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Preliminary processing of liquid organic waste in vortex layer devices

In recent years, society’s attention has been increasingly drawn to solving two inextricably linked problems — preventing the depletion of natural resources and protecting the environment from pollution.

The rapid consumption of natural fuel reserves and the limited construction of hydroelectric and nuclear power plants have aroused interest in the use of renewable energy sources, including the huge masses of organic waste generated in the agricultural, industrial, and municipal utility sectors. In this regard, the use of methods for biological conversion of organic waste with production of biogas and high-quality organic fertilizers while simultaneously addressing a number of issues related to environmental protection from pollution holds much promise.

Anaerobic processing of organic waste is carried out in special bioreactors — digestion tanks while the organic matter load on a reactor does not exceed 3–5 kg of organic matter (ОM)/ m3 of the reactor per day which leads to an increase in the volume of the reactor and, subsequently, to a rise in its cost; therefore, developing the methods for intensification of anaerobic bioconversion of organic waste is a relevant task.

The focus areas of intensification of anaerobic processing of organic waste for biogas production are as follows:

  1. Dividing the processing workflow into two or more stages with the optimal conditions for life-sustaining activity of microbial community ensured at each stage.
  2. Application of biological and physicochemical methods for preliminary processing of organic waste (anaerobic or aerobic hydrolysis, cavitation processing, mechanical grinding, thermal hydrolysis, ultrasonic processing, alkaline or acid hydrolysis, enzyme supplementation).
  3. Combining the processes of biological and thermochemical gasification of organic waste and intermediate products of their recycling using the benefits of each process.
  4. Applying the heat recovery and cogeneration to increase the energy efficiency of anaerobic treatment process.
  5. Adding high-energy co-substrates (slaughterhouse waste, off-spec food raw materials and food supplies, etc.) to processed waste.

In order to study the preliminary processing of organic waste from livestock farming, an experimental unit was created in the laboratory; the process flow diagram thereof is shown in the figure.

The unit operates as follows: the organic waste is fed into the receiving tank (the wastewater sludge and the imitated organic fraction of solid municipal waste); the pump  circulates the mixture through two reactors.

The steel needles (abradable working member) are located in the reactors and perform rotational and oscillatory motions under the influence of a magnetic field created by the inductor (the electric motor stator).

The magnetic field rotates at an increased frequency (100–120 Hz) due to the use of a rotation frequency converter mounted in the control cabinet (1).

А liquid-cooling system consisting of a jacket, a radiator, a fan, and a coolant circulation pump is used to cool the inductors.

With this kind of processing, the following positive effects are achieved:

  1. Pulverization that allows improving the rheological properties of substrate, carrying out the partial hydrolysis of complex organic compounds, improving the availability of nutrients for microorganisms, and heating the substrate.
  2. Penetration of ferromagnetic particles of the abradable working member (steel needles) into the substrate which makes it possible to shorten the bioreactor start-up period, to increase the formation speed and final yield of methane, to ensure a more complete decomposition of the substrate and a decrease in the required volume of the bioreactor, to increase the adaptive ability of microbial community to unfavorable conditions (for example, excessive accumulation of volatile fatty acids (VFA) or H2, reduced pH).

Using a vortex layer apparatus to increase the yield of pectin from beet pulp

Today, much attention is paid to the development of technologies for obtaining pectin from beet pulp – an effective detoxifier and radioprotector. In industrial production, pectin is extracted from apple and citrus pomace, beet pulp, sunflower baskets, but the pulp is the most economically profitable type of pectin-containing raw material. The content of pectin substances (on a dry basis) in plant raw materials is different: in an apple – (3.3 ÷ 19.9)%; in beets – (6.4 ÷ 30.0)%; in citrus fruits – (9.0 ÷ 14.0)%; in sunflower – (12.0 ÷ 24.0)%; in Jerusalem artichoke – (5.7 ÷ 11.7)%.

The largest amount of pectin substances if found in fruits and roots.

The classical technology of pectin production includes following stages: hydrolysis-extraction of pectin; its precipitation from the extract; drying and purification of pectin coagulum from impurities. The process of isolating beet pectin proceeds under more severe conditions than citrus and apple pectins. This is connected with the presence of acetyl ether groups in the beet pectin molecule, which negatively affect the gelling properties. That’s why pectin obtained from beet pulp is a low molecular weight product.

Harsh hydrolysis conditions favor the deesterification of not only acetyl groups, but also methoxyl esters, due to which beet pectin mainly exhibits gelling properties in the presence of polyvalent metals and a complexing ability.

The main consumers of pectin obtained from beet pulp are such industries as medicine, pharmacology, cosmetics, canning, dairy and bakery industries, as well as manufacturers of various biologically active food additives (AFA). Pectins can be used for the production of health-improving, protective, therapeutic and prophylactic products.

In the literature, there are many works on the intensification and greening of pectin production, but so far no studies have been carried out on the effectiveness of using the vortex layer apparatus for preparing raw materials before hydrolysis. It is known that the use of a vortex layer of ferromagnetic particles provides extremely effective mixing of the reaction medium. Acoustic waves and cavitation arise in the working chamber of the vortex apparatus, which leads to the intensification of mass transfer processes. However, complex physicochemical phenomena and processes that arise in the vortex layer are insufficiently studied and are often difficult to analyze. The prevalence and efficiency of the vortex layer apparatus has been shown in many works, moreover, these devices are already used in a number of industries.

Isolation of pectin substances was carried out by acid hydrolysis of samples of PGM, pre-soaked in a 1:15 hydromodule. One of the samples was homogenized in a vortex layer apparatus (AVS) for 15 s. The following scheme for obtaining pectin was used: acid hydrolysis of beet pulp with 2% HCl solution at 70 °C for 2 hours; separation of grains from the solution by vacuum filtration; concentration of the solution in a water bath to a dry matter content (DM) of 5%; precipitation of beet pectin from the concentrate with a double volume of 70% ethanol; separation of coagulum by vacuum filtration; drying the obtained pectin in a vacuum drying chamber at 30 ° C.

It was found that the pretreatment of the sample in AVS allowed an increase in the yield of pectin by 28.5%.

The results of the experiments showed that the vortex layer apparatus is an effective technology for the preprocessing of plant raw materials in order to increase the yield of pectin substances, which can be used in the future when creating production technologies.

Processing of Peat and Sapropel into Humates

Processing of peat and sapropel is used to obtain any new product with required properties. In particular, so-called humates or humic fertilizers, are obtained from this raw material.

What are humates (humic fertilizers)

They use humic fertilizers to stimulate plant growth. At its core, humates are organic substances. The processing of peat, sapropel, brown coal and other plant waste is used to obtain humic fertilizers. It usually takes 1-2 years for a layer of organic matter to form in a peat deposit, from which humic fertilizer 1 mm thick can be obtained. It usually takes 1-2 years for a layer of organic matter to form in a peat deposit, from which humic fertilizer 1 mm thick can be obtained.

Humic fertilizers show good efficiency in stimulating plant growth, while they are required much less than fertilizers of similar application. In addition, this type of fertilizer has a beneficial effect on the structure of the soil and activates soil microorganisms.

Humates History

In 1876, the German chemist Achard was the first to isolate the salts of humic acids from peat and gave their basic description. It was the German sciences that introduced the term “humic substances”.

At first, humic substances were used as a dye. It was a product, extracted from brown coal (19th century) In the twentieth century, humates already appeared in areas such as agriculture and medicine. But it hasn’t been systematic yet. More or less massively hu

In the USSR, the scientific foundations for the practical use of humic fertilizers were laid in the works of Lydia Hristeva and her followers.

The team under the leadership of Khristeva obtained humates from coal and carried out experiments to isolate humates from different plant species. The topic was continued by Belarusian scientists who isolated humates from peat.

Raw materials for obtaining humates

Nowadays, technologies for the production of humic fertilizers from bituminous and brown coal, peat and sapropel have been developed. The properties of fertilizers obtained from different types of raw materials are mostly the same, but in some points they can differ markedly.

Processing of peat and sapropel into humic fertilizers

The basic technology for extracting humic fertilizers from peat and sapropel is based on alkaline extraction followed by purification, since humic substances in insoluble form are practically of no value. As a result, salts of humic acids are formed, which dissolve well in water and have physiologically active properties.

Humates production using vortex layer devices AVS

We noted above that the layer of humic substances in peat does not form quickly and is not very large. Therefore, the main task in the production of humic fertilizers is to extract useful organic matter from peat without loss and convert it into a form that is easily accessible to plants. To do this, you first need to destroy the cellulose and lignin membranes of cells, which contain useful substances.

GlobeCore company uses AVS vortex layer devices for solving this problem. Through this devices, peat is dispersed in water due to the intense influence  on it from the side of ferromagnetic particles, which move along complex trajectories under the action of a rotating electromagnetic field. During movement, these particles collide with peat particles, with each other and with the walls of the working chamber. As a result, peat particles are crushed and more than 80-90% of them are no more than 15 microns in size. This is sufficient for the most complete extraction of all useful organic substances, the content of which after processing in the vortex layer apparatus is noticeably higher than before processing.

Thus, the processing of peat in the apparatus of the vortex layer AVS makes it possible to obtain a liquid substance, which in its essence is a humic fertilizer with all the properties necessary for plant growth.

Microcement: production on vortex layer devices AVS (nanocement)

Microcement is a material used to strengthen structures made of stone and concrete in order to increase their strength and water resistance. In fact microcement is crushed clinker with additives. Depending on the original components, there are different types (brands). Also the brand is determined by the particle size distribution.

With the addition of water to the binder, a liquid suspension is formed. The ratio of water to cement varies from 0.7 to 8 units. Due to its high fluidity, the suspension can be used as an analogue of water, glass or polymer liquid.

Stone, concrete and reinforced concrete constructions have multiple pores and cracks,  which are introduced by the suspension. This approach makes it possible to strengthen the structures, since microcement is made from ordinary Portland cement and the mineral base guarantees the compatibility of the suspension with the material to be strengthened.

Benefits of using microcement

Let’s consider what is the advantage of using microcement:

  • the service life of the fortified structures is practically unlimited
  • the transition of ordinary soil to the state of soil concrete or rocky soil after strengthening with a binder;
  • high water resistance of compacted soils and concrete structures;
  • environmentally friendly and safe product;
  • high compatibility with concrete; homogeneity with cements;
  • ease of preparation of suspension and spraying of injections;
  • economical consumption of material by regulating the water-cement ratio;
  • the ability to carry out operations with a binder at subzero temperatures – from – 10 0C (using warm water and insulation of hoses);
  • ensuring the strength of the foundations without negatively affecting the structure of the foundations of structures.

Microcement production technology. GlobeCore equipment

Vortex mills are used to produce finely ground material such as microcement. GlobeCore company developed and produced equipment operating on the principle of changing one type of energy to another under the influence of an electromagnetic field.

These are vortex layer devices – AVS-100 (AVS-150).The design of the installation consists of a working chamber in which ferromagnetic elements move randomly under the action of a rotating magnetic field. In addition to particles, materials in the device can be crushed using knives, tubes or a rotor. Carbon steels, nickel or any other metals with ferromagnetic properties are used as materials for grinding elements. The units are equipped with a cooling system and a control panel.

The GlobeCore company produces vortex devices of various designs and capacities. As well as laboratory versions for research and development activities and the production of new materials.

Increase of cement activity

Currently, the worldwide tendency is such that cements with a high content (more than 35%) mineral additives are replacing traditional pure Portland cement, such as blast furnace slag, silica fume, fly ash, limestone flour, natural and artificial pozzolana.

The expediency of increasing the share of mineral additives in cements does not raise doubts for cement plants, and at the same time, it is not always unambiguous for cement consumers.

Thanks to separate technologies for grinding individual components and subsequent homogenous mixing, it became possible to purposefully regulate the grain-size distribution of cement, to obtain cements with optimal dispersion. However, given the current shortage of high-quality cement, there is no need to talk about the use of cement of the corresponding grade today. It is good if you manage to work with the same reliable supplier and cement that meets European standards.

And it is very difficult to obtain a certificate for the supplied cement with actual characteristics in terms of activity, bulk density, dispersity and other parameters, and not the spread allowed by GOST. Therefore, only large enterprises with well-equipped laboratories can afford to use mineral additives, for example, blast-furnace slags with optimal dispersion, which have a functional dependence on the dispersity of cement.

The efficiency of cement can be increased (and, consequently, its consumption can be reduced) by increasing the fineness of its grinding. It is well known that the main properties of cement, including its activity and hardening rate, are determined not only by the chemical and mineralogical composition of clinker, the shape and size of alite and belite crystals, the presence of certain additives, but also, to a greater extent, by the fineness of the grinding of the product, its granulometric composition, as well as the shape of the powder particles.

In precast concrete factories, in order for concrete to reach stripping strength as soon as possible, they often go for an overestimation of the concrete grade by increasing the cement consumption.

This can be avoided by using a binder of a finer grinding: with such a binder, concrete hardening at an early age is faster. You can save cement in another way: add sand, limestone, ash or some other filler to the cement and grind the cement with it. However, studies show that the binder grade decreases, although not entirely in direct proportion to the amount of aggregate introduced.

To obtain concrete of grades up to 200 and even higher, such a binder is quite acceptable. Depending on the amount of added aggregate (30-50%), up to 30% of cement can be saved.

For example, some manufacturers of disintegrators assure that the joint grinding of commercial cement with limestone powder and a plasticizing additive increases the strength of the samples at the initial hardening period by at least 46%, and when one fifth of the cement is replaced with a micro-filling additive, the strength gain at the age of 3 days will be more than 90%.

However one should be careful with such statements. It is possible to believe in these figures for long-stored cement, with a fineness of 2000–2500 cm2/g and a very poor granulometry of cement grains, but for cements with a grind of 3500–4000 cm2 /g, it is doubtful, especially for cements with mineral additives. However, to obtain a highly active fast-setting cement, it is necessary to increase the fineness of grinding from the usual 2000–3000 cm2/g to 3500–4500 cm2/g, at the same time, an increase in the specific surface area of ​​the cement powder over 6000 cm2/g is doubtful and there are many questions and not fully understood.

Cement grinding with additives has become an epidemic. The quality of the additives is not controlled – the ashes are unstable and contain unburned coal. In the USA, the standard establishes the maximum level of unburned coal in ash for its disposal into concrete – 3.5%. When using ash, additional organic additives are introduced, which reduce the entrainment of air into concrete by coal particles. Obviously, they do not do this in our country.

High quality cement implies a whole range of properties, not just 28 days compressive strength of the cubes. Indeed, fine grinding increases the rate of hydration and rapid strength development, and reduces the proportion of unreacted clinker in concrete (mainly C2S). But at the same time, the rheology of cement changes dramatically and it may no longer have properties that allow it to be transported to silos and then fed by a feeder to a concrete mixer. Moreover, rapid hydration can create fast setting problems.

In order for conventional factories to be able to introduce these technologies, ready-made small technological lines, or separate units of the AVS type, are needed. Some scientists find it profitable to supply the factories with cements in the form of clinker. Grinding sections provide the most economical consumption of binders, allow using local raw materials as mineral additives, including waste, and allow wet grinding. For the organization of grinding can be used small-sized devices located in the concrete mixing shops between the batching and mixing sections. There are single copies of successful installations, such as an electric mass classifier (EMC), effective magnetic induction disperser reactors with a vortex layer of ferromagnetic particles  (АVS-100, АVS-150) using an alternating electromagnetic field to activate cement and fillers, disintegrators of wet grinding (Fig. 1).

Fig. 1

The maximum economic effect from the introduction of mechanical activation into the concrete production technology is achieved only with the correct combination of such processing parameters as the selectivity of final grinding of commercial cement with the ABC vortex layer devices, the optimal energy intensity of the mixing process and the availability of raw components, again with the ABC vortex layer devices. The process of cement activation is not only obtaining the optimal grain size, shape and surface of the cement grain, but also ensuring its complete hydration.

GlobeCore is ready to help introduce cement activation lines into existing production lines, grinding it to any fineness, AVS is able to grind to a dispersion of 3-5 microns per dry, while the productivity of an AVS-100 type apparatus will be about 100 kg / h, which is not much not a little for a cost of 4 kW, we get grinding from 70-80 microns to a size of 3-5 microns in 1 hour

Electromagnetic nano-mill for decontamination of liquid pig and cow manure

Livestock production generates large amounts of liquid manure, which may contain a variety of pathogenic microorganisms and helminth eggs. If such manure falls into the environment without preliminary treatment, it will cause epidemics among the local population. If there is no prompt response, the epidemics can spread to the neighboring towns and villages.

The microorganisms in liquid manure that can cause the greatest danger are infectious agents such as:

  • Salmonellosis;
  • Leptospirosis;
  • Brucellosis;
  • Anthrax and others.

Now the livestock farms use the following method for deteсting pathogenic microorganisms in liquid manure. The manure is kept in special containers for the incubation period (5 days) of the most dangerous pathogens. If during this time there was no outbreak, the manure can be placed in permanent storage, and used for composting. Otherwise it goes through a decontamination process.

The traditional methods do not always give the desired results. Therefore, GlobeCore offers the equipment for decontamination of liquid pig and cow manure: an electromagnetic nano-mill (AVS).

The AVS regrinds manure particles to less than than 1 mm, destroys weed seeds, pathogens and helminths and their eggs.

Experimental studies confirm that the use of electromagnetic nano-mill for disinfection of liquid manure:

  • Achieves complete decontamination and cancels manure quarantine period;
  • The manure can be used as fertilizer straight after treatment;
  • Ensures a high level of manure homogenization, reducing the costs of storage, and ease of loading and further use.

Globecore Participates in a Vital Project in North Macedonia

For the first time, The Ministry of Ecology of the Republic of North Macedonia is involving private companies to help find a solution to the problem of removing hexavalent chromium from the local waste dump.

For the last four decades, more than 2 million tons of waste, generated by Jugochrom factory, were simply stored with no further purification. The most dangerous poison, 100% concentration of Hexavalent Chromium, was flocculated and formed lakes a couple of meters away from the Vardar river, which supplies water to Skopje, the capital of Macedonia.

The residents of the surrounding areas are naturally alarmed: the water is poisoned; the soil cannot be used for agriculture. But the local community has no other source of water.

GlobeCore’s partners, the company SULA DOO KICHEVO, represented by Mr. Djevit Suloski and Mr. Stanko Illik Popov, a chemical engineer, initiated an Environmental Impact Assessment study into this problem. As a result, a series of tests were undertaken, and Vortex Layer Technology was tested and proved its high efficiency.

In the near future, the first process line that includes a Vortex Layer Device by GlobeCore will be installed at the Ferro-chromium dump in the Republic of North Macedonia.

This project makes us proud to be working at GlobeCore!

We will keep you posted on the results.

GlobeCore at Aquatech-2019

Amsterdam hosted the largest water resources convention in the world, Aquatech-2019 on November 5-8.

This year’s exhibition gathered participants from more than 147 countries, while the number of specialists attending, including the participants, exceeded 27000.

GlobeCore presented one of the latest developments, a wastewater purification complex based on the vortex layer ferromagnetic layer machine. This is a new wastewater treatment technique that generated considerable interest due to the following advantages:

  • reduction of chemicals used in the wastewater treatment process;
  • increased rate of processing (mixing, settling etc);
  • reduction of purification facility footprint by eliminating large mixers;
  • reduction of power consumption.

Participants from various countries, who visited our booth, noted the practicality of the technology to address the issue of effluent purification in leather production, electroplating, agriculture, petrochemistry etc.

Activation of Catalysts for Carbon Nanomaterial Production

The most important stage of preparing heterogeneous catalysts for carbon nanomaterial (CNM) is their activation, which is understood as a complex of physical influence on the catalytic material, which allows to significantly increase the efficiency of nanostructure synthesis.

This can be achieved by researching mechanical (dispersion) and physical (electromagnetic and ultrasonic) activation methods.

One of the most important factors defining catalyst efficiency is its granulometric composition. It is known that reduction of the particle size (less than 3 nanometers) causes capsulation inside nanotubes, while increasing it above 25 nanometers leads to uneven size distribution and defects in nanotubes. This is due to the fact the using large catalyst particles (25 to 100 nanometers) prevents carbon scattering from the surfaces where hydrocarbon decay occurs to the surfaces where carbon is deposited; as a consequence, no CNM growth occurs on such particles. Therefore, it is important to define reasonable catalyst particle size, as well as dispersion and classification methods.

Note that dispersion of catalyst microparticles causes both the reduction of size and the changes in the microstructure, e.g. destruction and reduction of pore depth, increasing the boundary of nano-seeds, where graphitized carbon is deposited.

Catalyst was activated in a drum mill and an electromagnetic vortex layer device (AVS). The distinguishing characteristic of the vortex layer in electromagnetic units is the multitude of high frequency and strength shocks, as well as friction, which not only break solid particles, but significantly activate their surfaces due to the deformation of their crystalline lattice. Enormous energy is concentrated in a volume of this process, which direct influence on the material. The influence is so high that it changes the structure as deeply as the atom’s valency shells. The process causes deep changes in the structure of the material.

Mean energy conducted to a volume of the vortex layer reaches 103 kW/m3. This is several orders of magnitude higher than in vibration mills, for instance. Besides, the energy is localized in certain areas, e.g. in the locations where the ferromagnetic particles collide, where mean power reaches even higher.

The electromagnetic vortex layer unit consisted of a process section and a control section, connected by oil tubes and a power cable. The process section consisted of a support, an enclosure, an induction coil for the rotating electromagnetic field, and a detachable operating chamber.

The catalyst activation process was performed with 1…1.5 mm by 10…15 mm PVC encapsulated ferromagnetic particles.

The chamber was loaded with 0.120 kg of the catalyst and 0.060 kg of ferromagnetic particles; retention time varied from 5 to 60 seconds. The granulometric composition of the Ni/MgO catalyst after the dispersion was done by fractionating sieve analysis. The catalyst after activation was separated into fractions and used for CNM synthesis under a unified method of testing various catalyst samples.

The results of the experiment show that the optimal duration time for the finest grinding constitutes 10 seconds, with initial catalyst particle size of 500 micron.

The observed increase of catalyst particle size after 10 or more seconds of dispersion is apparently due to the fact that with time the particles accumulate sufficient energy for spontaneous aggregation.

The analysis of the influence of the catalyst size composition on the mean output of CNM leads to the conclusion: the output increases in inverse proportion to catalyst particle size. This is due to the increased active surface of the catalyst. The experiments demonstrated that the actual method of catalyst dispersion has no significant influence on nanomaterial output.

GlobeCore extends invitation to the International Construction & Utility Equipment Exposition-2019

GlobeCore invites all businesses and parties interested in the implementation of innovative technologies to the International Construction & Utility Equipment Exposition.

This event is biannual, and this year will be hosted by Kentucky Exposition Center, Louisville, Kentucky on 1-3 October. The exhibition focuses, among other things, on electric power transmission and distribution, wastewater treatment, natural gas supply etc.

GlobeCore will be represented in the first two categories by the CMM-G designed to change oil in wind turbine gearboxes and the AVS vortex layer device. You can see these machines and speak with our specialists at booth 2240.

The CMM-G simplifies and accelerates oil change in wind turbines. To protect the new oil from instantly becoming contaminated with impurities left in the gearbox after draining the oil oil, the machine also washes the gearbox with special flushing oil. As for the vortex layer device, it increases the efficiency of the existing wastewater purification systems, reducing process duration and chemical consumption.

Looking forward to meeting you at International Construction & Utility Equipment Exposition-2019!

Cement Grinding in Ball Mills and Vortex Layer Devices

Cement and concrete are the second most used substances in the world, after water. On average, the per capita consumption of cement is one ton. This material is widely used as a binder in the production of concrete, reinforced concrete and various construction mixes. The demand for cement in construction of new buildings, repairs and reconstruction is always high.

The process of cement production includes several stages and concludes by grinding clinker with the addition of gypsum. Grinding precision is an important characteristic of cement, since it defines the amount of material capable of hydration. The rate of hydration and strength increase also depends on this parameter. Grinding processes are quite energy intensive, with up to 20% of the world’s energy production consumed by grinding equipment. Clinker grinding accounts for approximately 70% of energy costs in cement production. The objectives of the cement production industry at the modern stage are therefore as follows:

  1. Improvement of material grinding precision.
  2. Implementation of simple and reliable grinding machinery.
  3. Reduction of energy costs.

Grinding cement in ball mills

The principle of the ball mill operation is simple: it consists of a rotating drum and grinding media (cylinders, balls etc). The material is placed into the drum which starts rotating. The grinding media and the substance both come in circular motion and at a certain point drop from the walls the bottom of the drum. The grinding is achieved by attrition (particles of the ground substance and the grinding media move relative to each other) and impacts. Ball mills are most commonly used in cement factories to grind the raw material and finely grind the cement.

The use of ball mills in cement grinding is due to several factors, among which are relatively simple design and high processing rate. However, these machines have certain limitations as well. It is known that only 2 to 20% of the energy is consumed by the grinding proper, while the rest is expanded on overcoming friction, on vibrations and is dissipated as heat. Ball mills also are material-intensive due to high wear of the components. These mills are also very noisy.

Is there an alternative to ball mills? In this article we will look at one of the possible options: the vortex layer device.

The principles of vortex layer

The vortex layer device is, in a sense, similar to the ball mill, but the effect on the processed material is different in principle. The first similarity is the chamber, where the material is ground. However, the chamber of the vortex layer device is stationary, smaller than a drum and is always made of a non-magnetic material. The second similarity is the presence of grinding media (which, in the case of the vortex layer device, are cylindrical and made of ferromagnetic material). While the grinding media in the ball mill is put into motion by the motion of the drum, in the case of the vortex layer device, the grinding media moves along complex trajectories under the influence of a rotating electromagnetic field. This field is generated inside the chamber by electromagnetic induction coils. In fact, the design of the machine is similar to a short-circuited cage motor without the rotor (the rotor being replaced with a tube, i.e. the processing chamber).

Vortex layer device

The primary electromagnetic field created by the external power source, interacts with the electromagnetic fields of the ferromagnetic particles, creating several beneficial effects:

  • direct action of the grinding media on cement;
  • magnetostriction (mechanostriction);
  • electrophysical phenomena etc.

Mean power of these effects is such that not only cement is ground and activated, but the process is sharply intensified as well. Every ferromagtnetic particle is both a grinding and mixing medium. Moving along complex trajectories, these particles cover the entire volume of the chamber – another important distinction of the vortex layer device from a ball mill. If the process takes tens of minutes and hours in other mills, the required retention time in vortex layer devices is measured in seconds or minutes.

There are several parameters that affect the efficiency of the grinding  and activation process in the vortex layer device:

  • the strength and the rate of rotation of the magnetic field;
  • process chamber volume;
  • process chamber filling ratio (with both the ferromagnetic particles and the material);
  • the ratio of the particle length to diameter.

These parameters can be optimized experimentally, depending on the types of the processed material.

Comparing the performance of the vortex layer device and the ball mill

Vortex layer devices are superior to ball mills in several respects. Specifically, vortex layer devices are multifunctional. Unlike the ball mills, they can grind cement extremely fine without loss of efficiency, while at the same time activating the material with the electromagnetic field. All the processes occur a lot faster. E.g., increasing the mean surface area from 2800 to 6800 cm2/g is achieved as soon as within 120 seconds of processing. The noise output of the device is negligible, as compared to the ball mill. Cement can be activated even without ferromagnetic particles, simply passing it through process chamber.  In this case, the processing capacity increases severalfold.

Brief processing of cement in the vortex layer device ensures a reduction of concrete hardening time under natural conditions, a reduction of cement consumption or improved concrete grade, as well as achievement of high mix plasticity. The use of activated cement in all cement compounds ensures high physical and mechanical characteristics of the products.

The vortex layer device can also magnetize water for concrete mixes. Using magnetic water for mixing significantly improves the product strength. Regular water involves a lengthy period of cement crystallization, whereas in the case of magnetic water, the plastic strength starts growing almost immediately after mixing.

Probably the most important benefit of the vortex layer device is high efficiency of energy use. Mean energy consumption per 1 ton of ground cement is several fold less than that in the ball mill.

A comparison of the vortex layer device and the ball mill in cement grinding

Parameter

Ball mill

Vortex layer

Effects on ground material

Attrition, impact

Rotating EM field, direct impacts of ferromagnetic particles, magnetostriction etc

Possible grinding methods

Wet, dry

Wet, dry

Mean surface area of cement, cm2/g

Up to 5000

8000 and above

Projected means energy costs of final grinding, kW·h/t (depending on required grinding fineness)

40-70

4-10

The conclusion is that the vortex layer device used for cement grinding addresses three main issues of the cement production industry: it increases grinding fineness and reduces the energy costs of the process, while at the same time remaining simple and reliable in operation.

GlobeCore in the Press: Water & Wastewater Asia Magazine

The next issue of Water & Wastewater Asia magazine, published with the support of the Singapore Water Association, out in June.

The magazine publishes the first part of an article titled Using the Vortex Layer of Ferromagnetic Particles in Wastewater Treatment article by GlobeCore’s service manager Frank May.

The first part of the article deals with the principle of the electromagnetic vortex layer device. The piece includes the results of testing the technology in treatment of wastewater by reduction of hexavalent chrome, sedimentation of heavy metals, neutralization of acidic and basic wastewater and oxidation reactions. These results confirm the ability of the vortex layer machines to improve the efficiency of the existing wastewater treatment facilities.

See the first part of the article in the original. The second part is to be published in the next issue of Water & Wastewater Asia, expected to be out in September this year.

Vortex Layer Devices in Gold Production

Gold is used in several fields:

  • as part of national reserves;
  • in medicine (dentistry, pharmaceuticals and cosmetology). In this case gold is used in implants, medicines and cosmetics. The amount of gold used in this field is relatively small and remains below 2% of the total demand;
  • electronics (information technologies and telecommunications). In this field gold is used as a superconductor, in electroplating, as a connector in integrated boards, in wiring and cables. This field consumes about 8% of total gold demand;
  • chemical industry (as a catalyst);
  • construction industry (gold plating, decorations);
  • jewelry. This field consumes up to 87% of the total world production of gold.

The costs of gold production has been rising in recent decades. In 2014, the cost of producing one troy ounce of gold was 1200 dollars. This tendency is due to the reduction of the large deposits and mines. The number of new deposits discovered remains the same. The mean content of the metal in ore decreased from 1.5 to 0.8 g/ton, which makes it necessary for the producers to research ways to increase ore processing efficiency.

Using the vortex layer devices in gold ore processing

Extraction of gold and silver from the ore where the metals are rather thinly distributed in arsenic pyrite and pyrite requires decomposition of sulfides (roasting, bacterial leaching or pressure reduction).

To reduce the amount of material for roasting and increase the concentration of gold (in most cases gold is associated with arsenic pyrite), the concentrate is separated by flotation into arsenic and pyritic fractions.

All methods of concentrate separation are based on different oxidability of arsenic pyrite and pyrite surfaces under the influence of oxidation agents (pyrolusite, potassium permanganate, lime etc). However, all chemical separation methods have the following limitations: the process is very sensitive to slight changes of conditions; the collection and removal of the collecting agent from the concentrate requires multiple washes and involves partial loss of the solid matter with drains, as well as the need to constantly add new agent and extra measures to neutralize the waste stream to minimize the environmental impact.

The processes of dispersion and surface activation of the processed materials can be enhanced with the vortex layer devices (AVS). The processed material (dry or pulp) is intensively mixed by ferromagnetic particles, under the influence of electromagnetic fields, induced currents and discharges, acoustic shock waves and heat.

For experimental purposes, an airtight non-magnetic steel container was placed into the operating chamber. The subject of the experiment was flotation concentrate of the following composition: 89 g/t Au; 15 g/t As; 20,32 g/t S; 1,43 g/t FeO; 32,11 g/t Fe2O3; 8,1 g/t Al2O3; 23,8 g/t SiO2; 1,43 g/t TiO2.

Multiple experiments to separate the bulk concentrate without prior processing in the AVS yielded no positive results. In the best case scenario, flotation in basic medium using lime and copper sulfide reduces arsenic content in the pyrite product from 12-13% to 5%.

Subsequently, flotation separation was performed after pre-treatment of the concentrate in the AVS. A 200 gram concentrate sample (solid to liquid phase ratio 1:1) was processed at рН=7.8 for a certain amount of time (container diameter 100 mm). The weight of ferromagnetic particles was 30 grams, the ratio of length to diameter was 8.3. Immediately after treatment, the concentrate was transported into a 1-liter flotation machine and was subjected to flotation with butyl xanthate (50 g/t).

The data received show that the content of arsenic in pyrite product is reduced from 16 to 4% with 10-11 minute treatment. Approximately 89-90% of As and 90-91% of Au was extracted into arsenic concentrate with a yield of approximately 62% (As and Au content was 23-24% and 125-130 g/t).

An important factor defining the efficiency of the vortex layer processing of various materials is the amount of processed material per weight of the ferromagnetic particles.

Research shows that in a closed system the optimal ratio of concentrate mass to the mass of the particles is 8 to 12. Pretreatment of the concentrate at the ratio of 10 and subsequent flotation ensure production of arsenic concentrate with arsenic content of 2.4% with extraction of arsenic to pyrite concentrate 5-5,5%.

During the pre-treatment of the concentrate in the AVS, the surface of the minerals, covered with a xanthate film, is influenced by a number of factors, such as induced currents, electric discharges, local pressures, heat, abrasion etc, which causes the collecting agent to desorb from the minerals and partially decompose.

At the same time, after the process the pulp contains part of the collecting agent, which can again be adsorbed by the mineral surface and reduce the efficiency of the subsequent selective flotation. Adding activated charcoal (up to 1 kg/t) to the AVS process improves these parameters.

The resulting pyrite concentrate contains 1,7-1,8% As, which makes it possible to process it at copper mills. Arsenic concentrate contains 26-27% As, 130 g/t Au if 95-95,5% and 92-93% respectively are extracted into it.

Apparently, a brief pretreatment process of gold, arsenic and pyrite concentrates in the vortex layer device significantly improves the results of the following selective flotation and ensures a higher gold concentration of gold in the arsenic concentrate.

The Forces in the Vortex Layer Device Chamber Which Impact Biodiesel Production

The action, motion and energy of the ferromagnetic particles are the decisive influences on the methanolysis process. In turn, these factors are defined by the shape of the particles, their diameter, the ratio of length to diameter, the amount of particles in the chamber and a few other things.

The amount of particles in the operating chamber of a rotating electromagnetic layer device is directly linked to the efficiency of their influence on the reaction mass.

According to theory, the entire layer rotates as a whole. The motion of the particles in a rotating electromagnetic field is possible only up to a certain amount of particles, at which point all particles stop moving.

Large cylindrical particles rotate relative to the axis of the unit, but also move relative ot each other. In other words, the original idea was that the effect of the ferromagnetic particles boiled down to regular mechanical stirring and grinding.

If there are few particles, all of them should move mostly on circular trajectories. If there are a lot of particles, they collide between each other and the walls of the chamber, which causes the particles to turn and tumble, changing their trajectories.

Later experiments revealed new effects, occurring with the steel cylindrical ferromagnetic particles in a rotating electromagnetic field.

The forces and momentum cause the particles to move in a complex manner: forward motion with frequent and sharp changes of velocity and direction and rotational motion with alternating angular speed. Each particle moves independently of the others. Experiments show that the motion begins with the induction in the chamber exceeds 0.09 tesla.

There are two distinct tendencies of motion here. First, the entire layer of particles (due to centrifugal forces) moves at a certain distance from the induction coil axis in the direction of EM field rotation (the induction coil is vertical). Second, the motion of most particles combines the motion along a circle with complex large amplitude oscillations (the amplitude approximates half of the particle length) relative to their centerpoints.

If would seem that local electromagnetic fields are generated around each particle, which change the structure of the magnetic field in the induction coil in a pulsatile manner.

With complex mechanical and magnetostrictive oscillations (due to the delay of the motion relative to EM field rotation, as well as magnetoelastic effect during collisions), each particle becomes a source of cavitation. The processed liquid ingredients (a mixture of vegetable oil and the solution of methanol and base) have a very small compression coefficient, which means that large pressure changes are accompanied by small changes of volume.

The oscillations of the ferromagnetic particles in a fluid generate negative pressures. These negative pressure cause the formation of vapor-filled caverns, which expand and reduce the negative pressure. The continuity of the liquid is disrupted, and it is necessary to define the position of the caverns and the motion of the caverns’ boundaries. The tendency to form caverns in a liquid in idle state shows that in the presence of cavitation cores (microscopic inclusions of air with some vapor), the pressure is reduced to zero.

The pressure created at the boundary of a small spherical bubble due to the interfacial tension, is so high that it cannot be balanced by the vapor pressure, while the air under such pressure should rapidly dissolve in the fluid.

The intensive motion of the particles cause the gas bubbles to almost immediately disperse and fill with saturated vapor of the processed liquid, creating the conditions for acoustic cavitation. Particle motion drives the intensive motion of the fluid, creating the conditions for discontinuity of the fluid, i.e. stream cavitation.

We assume that the process efficiency of the devices with a rotating EM field is due to several factors which influence the processed fluid together:

  • the rotating EM field magnetizes the particles, which interact with each other, the fluid and the chamber’s walls;
  • acoustic shock waves are generated by the cavitation in the chamber, intensifying mass exchange processes;
  • the motion of a large amount of ferromagnetic particles in the induction chamber is accompanied by intensive collisions and release of energy;
  • each particle is, in a sense, a mini electrolysis devices, which saturates the chamber with ions, accelerating chemical processes;
  • magnetic polarity reversals of the magnetized particles generates magnetostriction. The number of reversals seems to significantly exceed the number of particle collisions. The change of linear dimensions are very rapid. The result is a force impulse. It is probably that each particle radiates strong impulses as it moves, significantly intensifying the chemical and diffusion processes;
  • the particles contact each other, forming a short circuit, with strong induced currents and micro-arcs. The released heat also facilitates process intensification and direct diffusion of matter;
  • the magnetostriction impulses, cavitation, induced currents and micro-arcs increase the area of interaction (phase boundary) by several orders of magnitude, increasing the “surface energy” and the rate of vegetable oil methanolysis.

All the forces and factors are synergistic and create previously unknown phenomena in the vortex layer devices, improving the efficiency and intensity of the chemical processes.

Vortex Layer Device Design Features

Operation of the rotating magnetic field devices is based on one of the most characteristic features of multiphase currents, that is, generation of a rotating magnetic field, which serves as a driving force for the intensive chaotic motion of ferromagnetic particles. The particles carry and transform the energy of the field.

The most common practical use of these systems are various grinding and mixing processes. The vortex layer systems have proven to be quite efficient in this field, compared to the traditional vibration or ball mills, as well as other mechanical mixing devices. The benefits include sharp intensification of the processes and reduction of power consumption, reducing product costs, as well as design and manufacturing simplicity, which do not involve complex technologies, and reliability in operation.

Regardless of the process in the vortex layer, the main components in the systems, which maximize the effects of the vortex layer, are the same (Figure 1).

Vortex Layer Device

Figure 1 – A rotating magnetic field system: 1- enclosure; 2 – induction coil; 3 – cooling jacket; 4 – operating chamber; 5 – ferromagnetic particles.

The main components are the electromagnetic system (the induction mechanism generating the rotating field), the ferromagnetic particles and the operating chamber that contains them.

Other component depend on the specific requirements for the process the system is used for. The machine can run a batch process or a continuous process, where the ingredients are supplied into the operating chamber from one end and the product leaves the chamber from the other end. The strong magnetic field holds the ferromagnetic particles so they are not carried out of the chamber by a liquid or gas flow. An important feature of a rotating electromagnetic field device is the absence of dynamic seals and the possibility to make the operating chamber completely airtight.

Let us take a look at the components of the machine. The rotating field can be created by either internal or external cylindrical induction coils.

However, with the identical number of pole pairs, the magnetic field of an internal induction coil dissipates much faster with distance, than in the bore of an external induction coil. This makes external cylindrical induction coils much more practical for the rotating field devices. In this case the electromagnetic system is a circular multiphase system of coils installed in the groves of the magnetic core.

An important condition for the efficient operation of the vortex layer and the entire system is the uniformity of the field in the cross section normal to the induction coil axis. In such field, the ferromagnetic particles, which rotatie with alternating angular velocities, are evenly distributed in the operating chamber, ensuring that the entire ingredient flow is involved in the process. Two-pole inductors generate the most uniform field.

One of the most important parameters of a vortex layer device is the magnetic induction in the center of the induction coil bore at idle, i.e. without the ferromagnetic particles. Induction defines the rate of ingredient mixing and dispersion, as well as the rate of chemical reactions in the vortex layer. For most vortex layer devices designed for the production of emulsions, suspensions and various chemical processes, the induction is in the range from 0.07 to 0.20 tesla. The length and internal diameter of the bore are also important parameters, defining the processing capacity of the devices.

Three AVS-100 machines commissioned in China

The ferromagnetic vortex layer devices are applied for intensification and improving efficiency of wastewater purification.

One of the latest orders for this equipment was filled by GlobeCore for a large factory in China. Three AVS-100 units are already operated in China, in cyanide and fluoride removal from wastewater.

In the case of two stage chemical neutralization of wastewater with simple and complex cyanides, cyanides are first oxidized to cyanates at pH 10-11.5, then the latter are hydrolyzed to nitrogen and carbon dioxide at pH 7-7.5. The process is performed in batches. The decontamination agent is sodium hydrochloride.

The implementation of vortex layer units makes it possible to complete decontamination in one pass at рН 9-10. Oxidizer consumption (chlorinated lime, sodium or potassium hypochlorites) constitutes 110% of the theoretically required amount. The alkaline agents used are soda solution or a Ca(OH)2 suspension in water. With the initial content of cyan ions at 8000 mg/l, the number drops after the purification to 0.12 mg/liter, from 4320 the amount is reduced to 0.02 mg/l and to 0.002 mg/l from 50.

Using the vortex layer devices also improves efficiency of fluoride removal. Removal of fluorine and converting phosphates into insoluble compounds occurs in one stage. The content of fluorine in purified wastewater in optimal conditions (рН 10-11) does not exceed 1.5 mg/l, while the phosphates are absent. The commonly used reagent is lime with 5-10% excess of CaO.

GlobeCore In The Media: the Cement Americas Magazine

The new issue of the Cement Americas Magazine came out in September 2018. The magazine published an article by Frank May, GlobeCore service engineer, titles The Promising Application of Vortex Layer Devices with Ferromagnetic Elements for Cement Improvement.

The article discusses one of the main reasons for cement deterioration which increases cement consumption and includes an analysis of equipment currently available in the industry for final pulverization of cement to improve its activity (such as various mills and dispersers). The author demonstrates how the currently existing mills are not always able to ensure the required results while consuming excessive amounts of electricity.

The alternative is the AVS vortex layer device. Mr. May describes the unit’s principle of operation and the results of practical trials for a concrete sample made from cement with and without AVS treatment. The results conclusively demonstrate the advantages of using these devices for activation and improvement of cement strength.

See the full article here (in the original language).

GlobeCore in the Press: Cemento Hormigón Magazine

The May-June 2018 number of Cemento Hormigón Magazine of Spain features an article by GlobeCore electrical engineer José Mora, titled “Re-trituración y mejora del cemento portland en los sistemas de optención de la capa vórtex de particulas ferromagnéticas”.  

The article describes GlobeCore experience in application of the vortex layer devices with ferromagnetic elements in the construction industry, specifically, to improve the properties of concrete. The article lists the results of testing samples made from cement after pulverization and activation in vortex layer devices. It also includes a description of the unit and its operation.

The article (in the original language) follows.

GlobeCore in the press : “Industrial WaterWorld” magazine

The fifth issue for 2017 of “Industrial WaterWorld” magazine published an article entitled “Decontamination of Oily Wastewater Using Electromagnetic Vortex Layer Devices”.

The article analyzed the main directions of cleaning and neutralization of wastewater containing oil, and the advantages and disadvantages of these methods. Also the article described  the principle of  operation of electromagnetic vortex layer devices with ferromagnetic particles, that have proven themselves in efficiently treating wastewater of various origins.

The article explored the possibility of using electromagnetic vortex layer devices for cleaning wastewater contaminated by petroleum products directly on ships and crafts. It established that the electromagnetic vortex layer device AVS produced by GlobeCore can easily be integrated into the existing ship systems. Wastewater treatment through the proposed technological scheme ensures the complete decontamination with the elimination of all possible waste.

GlobeCore in the press: published an article on electromagnetic vortex intensifier for wastewater treatment in “Water Today” magazine

The scientific and research magazine “Water today” in its August issue 8’17 published an article “Electromagnetic Intensification of Heavy Metal Removal and Wastewater Decontamination”.

The article addresses the problem of wastewater pollution as a result of industrial activities. For wastewater purification from heavy metals (chrome, zinc, iron, nickel, copper, iron, cadmium), is proposed an electromagnetic vortex intensifier AVS produced by GlobeCore.

The article shows the results of testing the laboratory AVS. It also shows a scheme of simultaneous wastewater treatment containing chromium, acid and alkali.

Production of coal-water slurry fuel with AVS

Electromagnetic field energy unit

A high price of traditional fuel (gas and heating oil) encourages to search for new cheaper fuel to reduce the cost of thermal energy. One of the most promising new products is coal water slurry fuel – a mixture of coal particles (fraction 1 … 70 μm), water and reagent. It is characterized by a good heating value and a high degree of combustion.

Advantages of coal-water slurry fuel

  • ignition temperature is 800-850 ° C;
  • combustion temperature – 950-1150 ° С;
  • calorific value – 3700-4700 kcal.
  • efficiency of carbon combustion  is 99%;
  • lower cost;
  • harmful emissions to the atmosphere are reduced;
  • fire and explosion-proof.

Preparation of water-coal fuel

Coal-water slurry fuel is produced from coal which has a high content of volatile substances. It is delivered to an open platform, then a front  loader feeds it into a receiving hopper of a grinder. Coal can be ground by ball mills, roller mills and hammer mills. Practically each of these mills is a complex and bulky equipment, that uses a lot of power. This calls for new and more efficient grinders for preparation of coal water slurry fuel.

Why AVS?

The design of the first AVS was proposed in the 60s of the last century. This device is an induction motor, that has an operating chamber instead of a rotor. The device is connected to a three-phase electric power that creates a rotating electromagnetic field of the industrial frequency. The material and  ferromagnetic elements are fed into the operating chamber. They begin to rotate and collide under the influence of electromagnetic field and other factors (high local pressure, electrolysis, acoustic impact, etc.), causing intensive dispersion and mixing of coal-water slurry fuel components.

An AVS unit doesn’t have the disadvantages of traditional industrial mills that have large overall dimensions and low energy efficiency. In addition, AVS can be integrated into existing lines for coal-water slurry fuel  production without significant changes and costs.

Test results of AVS-150

GlobeCore conducted studies of coal grinding and subsequent preparation of coal-water slurry fuel on AVS-150. The tests showed the following results:

  • re-grinding of 10-15 mm coal to coal dust not exceeding 300 μm;
  • re-grinding and mixing coal with water;
  • careful mixing eliminates a plasticizer;
  • AVS-150 approximate capacity for water-coal fuel production is 3 m3 / h;
  • energy consumption is 9 kW / h per metric ton. This indicator for a vibrating mill is 55 kW / h;
  • calorific value of produced fuel is 42,000 kcal.

Thus, it is possible to produce water-coal fuel on AVS-150 using cheap coal slurry, which is as good at heat transfer as gas or heating oil and more economical than they are.

AVS can be used in:

  • preparation of fuel for combustion;
  • preparation of coal-water slurry fuel;
  • co-combustion of coal and biomass.

Contact us to leave an application for purchase of AVS for the of coal-water slurry fuel production.

Modern Electroplating Wastewater Neutralization

Electroplating wastewater. Electroplating facilities and shops produce toxic solid waste in the form of ions of heavy metals, acids and alkalis that can cause water pollution. It is due to the electrochemical technology requiring large volumes of water.

Generally, the decontamination and neutralization of electroplating wastewater is performed by a special unit which uses reagent purification. Despite the mainstream use of this approach, it is not without flaws. Its drawback is ineffective wastewater treatment that leads to excess of unwanted substances in the water output. Other drawbacks of the reagent method are high reagent consumption and high salt content, which do not allow the water to return back into the cycle; it also requires large bulky equipment.

Therefore, scientists continue to search for new methods to improve the efficiency of existing technologies. A solution was found by GlobeCore in its magnetic mill (AVS). These devices were developed in the last century by Logvinenko. In his book “The Intensification of Technological Processes in a Vortex Layer Unit” he demonstrated the positive results obtained with the AVS in wastewater treatment. But the low capacity of the device precluded its mass introduction into the wastewater treatment industry, because a large industrial enterprise required many AVS units for neutralization of wastewater, until recently. The newly developed high-performance devices cover the necessary volumes of wastewater treatment.

The GlobeCore design department studied the effectiveness of the AVS for cleaning and neutralizing wastewater from electroplating facilities. The data is shown in the table below.

Heavy metal wastewater treatment from galvanizing plant using AVS 100

Parameter

Rating

Maximum concentration level (European Union legislation)

Before treatment

After treatment

1

рН

1,75

6,74

6,5-8,5

2

Fe, mg/l

9,7

2,77

2-20

3

Cu, mg/l

18,29

0,65

0,1-4

4

Ni, mg/l

5,8

<0,02 (not detected)

0,5-3

5

Cr+6, mg/l

19,08

<0,005 (not detected)

0,1-0,5

The use of the AVS-100 magnetic mill in wastewater treatment from electroplating plants reduces the concentration of heavy metals to values ​​not exceeding the maximum permissible concentration accepted in the European Union. It achieves complete absence of nickel and hexavalent chromium in the treated water and shows the possibilities of future use of the vortex layer devices in countries with more stringent demands for hexavalent chromium and nickel concentrations.

Wastewater treatment is immediate and does not require high expenditure of reagents. The sedimentation with the AVS occurs much faster than with a stirrer.

Physico-chemical methods of ceramic production wastewater treatment: coagulation and adsorption

Water treatment process. Ceramic production forms two major streams of wastewater.

The first stream is formed at the stage of preparing the slip casting of ceramic products, their mandrel, filling and bonding of parts and includes, mainly, a large amount of suspended clay particles and glycerol. The second stream is formed in the preparation of ceramic colors and contains pigments, which are made from different metal oxides. Since the streams are different and require different cleaning methods, it is not recommended to mix the streams and use separate treatment plants for each of them instead.

The wastewater with suspended particles of clay needs coagulation and sorption treatments to return the purified water and sedimented clay into the production process. The stream containing pigments must pass through coagulation treatment. Since this mixture is not used in the ceramic industry, it can be added into molding mass in production of bricks.

Coagulation treatment is used for natural and industrial wastewater mainly to purify it from colloidal suspension contaminants. The essence of coagulation is adding special coagulants. In most cases they are aluminum and iron salts, as well as their mixtures, also used are the salts of other polyvalent cations such as magnesium and titanium. Since the coagulants are the salts of strong acids and weak alkalis, they are hydrolyzed to form hydroxide salts which have a developed surface and can absorb various impurities. These particles coagulate with colloidal substances. The most commonly used today are aluminum, steel, and mixed aluminium-iron coagulants, which are mixtures of aluminum and iron salts.

Aluminium compounds used as coagulants are aluminum sulfate, aluminum hydroxysulfate, aluminum chloride, aluminum sulphate, sodium aluminate.

Removal of Heavy Metals from Wastewater Using Electromagnetic Nano-mills

Removal of heavy metals.. From the beginning of the 1970s, technological and scientific research has been increasingly directed towards protection and preservation of the environment, which is becoming more and more important around the world.

This is due to the irreversibility of negative anthropogenic impact, which is a real threat to the existence of mankind. It makes national conservation a number one priority.

The environment saturated with harmful substances, including toxic heavy metals, is becoming more dangerous to health and normal life of mankind. Adding to it is the increasing population, depletion of natural resources, an increase in industrial and agricultural production that creates worldwide shortage of fresh water. Besides, the development of industries such as optical, pharmaceutical and chemical, demands high quality treatment of wastewater. At the same time, the amount of wastewater increases, which, in turn, affects the environment and the state of water bodies. This demands the development of effective methods of water purification to remove undesired impurities.

By 1950s, wastewater was treated by distillation, but, unfortunately, this method requires bulky equipment and consumes a lot of energy. Since 1950, the deep wastewater treatment has been performed by ion exchange. The main disadvantage of this method is the chemical regeneration of sorbents with the use of significant amounts of corrosive reagents, as well as the complex design of equipment. From 1970, electrodialysis came into use, combined with reverse osmosis. However, large-scale development of this technology is limited by its high energy consumption and low productivity.

GlobeCore research shows that cleaning and neutralization of industrial wastewater could be seriously improved by the electromagnetic nano-mill (AVS).

These devices were developed in the 1960s-1970s and have since been applied in many industries improving the efficiency and intensity of various processes. The great results of the AVS are due to a variety of phenomena and effects which occur in the chamber of the unit. These effects are electrolysis, electromagnetic treatment, intensive dispersion and others.

Table 1 shows the results of wastewater treatment from galvanizing plant contaminated by heavy metals with the AVS-100 electromagnetic nano-mill, in comparison with the maximum permissible concentrations in the European Union standards.

Table 1

The results of treating wastewater from galvanizing plant removing heavy metals with the AVS-100 electromagnetic nano-mill.

Parameter

Value

Maximum

permissible concentration (European Union)

Before regeneration

After regeneration

1 рН

1,75

6,74

6,5-8,5

2 Fe, mg/l

9,7

2,77

2-20

3 Cu, mg/l

18,29

0,65

0,1-4

4 Ni, mg/l

5,8

<0,02 (not detected)

0,5-3

5 Cr+6, mg/l

19,08

<0,005 (not detected)

0,1-0,5

The data shows that the AVS -100 reduces heavy metal concentration in wastewater to values ​​not exceeding the maximum permissible concentrations specified by the European Union. Complete absence of nickel and hexavalent chromium in the water was achieved. The results demonstrate the efficiency of using the electromagnetic nano-mills in countries with more stringent requirements to hexavalent chromium and nickel concentrations.

It was also found that the electromagnetic nano-mill saves on the reagents. The process of sedimentation occurs much faster than when using devices with a stirrer.

Fish Processing Wastewater Treatment

The food industry, including the fish industry, is a source of organic compounds and water solutions of inorganic salts. These organic substances contain proteins and fats. They are washed by hygienic washing equipment with different types of detergents, resulting in different amounts of pollutants in the wastewater.

Their daily flow of concentrated wastewater varies between 5-7% of the total amount of wastewater. At the same time, the concentration of  impurities in this flow exceeds the maximum permissible value by 10 times or more.

The problem of wastewater treatment with such composition is connected with the origin and composition of wastewater. It requires new design of wastewater treatment equipment.

The solution could be in using baromembrane methods. This membrane technology is easy to use but is limited in certain conditions.

Industrial wastewater from fish processing facilities is generated by:

  1. defrosting, salting, washing and processing of fish;
  2. washing of equipment and production facilities.

The problem of discharge of wastewater from fish processing into municipal treatment facilities is the excessive number of pollutants.

Biological treatment used at treatment plants is not enough to remove fat. Therefore, the solution lies in combining classical physicochemical and biological treatments, and also in reducing the amount of detergents that pollute wastewater with chlorides.

Biotechnology in dairy wastewater treatment

Dairy wastewater treatment. The technology of food preparation creates waste varying in quantity, pollution, state of aggregation, etc.

Wastewater of the food industry is considered concentrated by the level of contaminants. It contains a significant amount of organic substances.

The most contaminated is the wastewater from alcohol, meat, dairy and sugar industries. Since these enterprises are situated mainly in urban areas, some of their wastewater is dumped into central sewage system. However, urban wastewater treatment plants work inefficiently. Moreover, the wastewater of most food companies does not comply with the requirements of their discharge into the sewer on the concentration of contaminants, causing violations of the rules and regulations.

Over the years, the food industry has been trying to solve the problem of wastewater treatment in the outdated sewage treatment plants based on traditional biological treatment technology, which was used to clean domestic wastewater. But this technique is not suitable for purification of concentrated effluents.

To solve the problem of treating concentrated wastewater, the anaerobic-aerobic treatment technology was proposed .

First, this technology sharply reduces the concentration of contaminants by methane fermentation, then finally treats the wastewater in aeration tanks with aerobic fermentation.

The implementation of methane fermentation coincided with the search for new, alternative energy sources, since methane fermentation produces biogas, which could prove to be a cheap source of energy. Biogas could be produced from both liquid and solid waste of virtually all food production facilities.

The problem of treating wastewater containing pharmaceutical substances

Treating wastewater. The efficiency of wastewater treatment in sewage treatment plants depends on many factors, among them is the presence of toxic substances in wastewater which affect activated sludge.

Typically, a pharmaceutical substance (medicine) is a mixture prepared by treating natural materials by synthesis or chemical treatment. These chemicals are released into sewage in micro concentrations, but some of these chemicals have an extremely negative effect, which in many cases exceeds the effect of known contaminants entering the drains in large quantities. Traces of pharmaceutical drugs were found in wastewater, surface water, activated sludge, oceanic sediments and annual rainfall and also in filters in municipal landfills in countries such as France, Germany, Great Britain, Denmark, the Netherlands, Sweden and the United States.

Wastewater from residential areas, medical institutions and pharmaceutical companies are discharged into municipal sewage, and then into treatment plants for the biological treatment. But even after the treatment the purified water that goes into natural waterways contains pharmaceutical drugs or their derivatives. This is explained by the fact that biological wastewater treatment in most cases is not intended to remove micro contaminants.

Chemical drugs poison the activated sludge microorganisms of treatment plants. The examination of toxic effects of pharmaceuticals show the negative change in the  biological nature of the activated sludge organisms, which changes the results of wastewater treatment.

The negative effects of pharmaceutical pollutants on the active sludge are various. Some of the pollutants slow down oxygenation of activated sludge, reducing its productivity, while others become food.

The remains of pharmaceuticals, after passing through biological treatment are discharged into surface waters and accumulate in the natural environment. They reduce the quality of water, violate the life-cycle of organisms and cause their abnormal development.

Wastewater Treatment With Microorganisms

Wastewater treatment. In the process of biological treatment of highly concentrated wastewater from industrial enterprises, food and light industries, the main role is played by microorganisms that colonize the treatment plants. These microorganisms use the substances contained in wastewater for their life-sustaining activity. These bacteria in the activated sludge are  Pseudomonas, Bacterium, Micrococcus, Bacillus, Corynebacterium, Thiobacillus. They perform the destruction of complex organic compounds and nitrogen compounds.

Biocenosis in a bioreactor occurs with the help of anoxic and aerobic technologies immobilizing microorganisms, hydrobionts and free-floating particles of activated sludge. These anaerobic-aerobic wastewater treatments are implemented in the food and light industries. They use Pseudomonas, oxidizing alcohols, fatty acids, waxes, aromatic hydrocarbons, carbohydrates and Nitrosomonas, Nitrobacter bacteria. In addition to bacteria, an important role is also played by invertebrates, algae, fungi, microscopic animals that form hydrobiocenoses in wastewater-treatment facilities.

The pollutants in wastewater and their concentrations and the place of their conglomeration, either  in the water or on its surface determine the treatment conditions: anaerobic, anoxic or aerobic.

The presence of rotifer, and worms (higher trophic level organisms in the food chain) in the aerobic bioreactor also improve wastewater treatment. These organisms eat away the detritus, bacteria and protozoa; they stop the increase of biomass, reduce the costs of recycling and disposal of sediment; mineralize biomass and improve sediment properties.

In bioreactors of wastewater treatment plants the immobilized  microorganisms form bio-conveyor of bacteria: small flagellates, ciliates, rotifers and worms effectively clean wastewater of contaminants, regulate the number of hydrobiont populations, which leads to a reduction of biomass.

Electrochemical treatment of industrial wastewater

Electrochemical treatment of wastewater. In recent years, the electrochemical methods of  industrial wastewater treatment became more popular than chemical treatment. It is due to a significant increase in prices of chemical reagents such as oxidizing agents, reducing agents, acids, alkalis, coagulants and flocculants. The other reasons to abandon chemical reagent treatment is the absence of secondary pollution of the treated water with anions and cations of salts, which makes the facilities environmentally safe; the purified water is reused in the production cycle, since its mineralization does not change, even reduced in some cases. The methods used for comprehensive treatment of multicomponent wastewater with different qualitative and quantitative composition are adsorption and sedimentation of impurities. The treatment plants are compact and easy to operate.

The most common method of electrochemical treatment of wastewater uses active coagulants of aluminum or iron cations in the solution for ionization (electrochemical dissolution) of metallic anodes with direct current. Metal cations react with water molecules and form hydroxides with high sorption properties for heavy metals, organic compounds and other components of wastewater, and also reduce the amount of chlorine anions and sulfates.

Electrocoagulation with iron electrodes forms ferrous iron, and by adding coagulant, it reduces the amount of hexavalent chromium and other contaminants, such as petroleum, oils, surfactants, other organic impurities.

Electrocoagulation is easily controlled by adjusting electric current and metal ions transition between electrodes.

Upgrading electrochemical treatment plants requires an inspection according  to safety standards and guides.

The main hazards of electrochemical treatment of wastewater, is the possibility of electric shock, electrolysis gas emissions, particularly chlorine, generation of fire and explosive dangerous mixtures of electrolysis gases (hydrogen) with oxygen and air, the possibility of generation of secondary hazardous substances by interaction of electrolysis components and wastewater.

Treatment of Wastewater From Galvanic Production

Wastewater system. The existing methods of electroplating wastewater treatment do not fully meet the requirements and regulations for wastewater discharge into waterways and the environment.

The reasons lie in the design and operation of wastewater treatment equipment. The difficulty is the comprehensive removal of the entire spectrum of pollutants used in industrial processes.

Furthermore, it is very important to strictly follow the environmental rules and requirements of wastewater discharge into waterways. These rules demand multi-stage treatment technologies and development of new and improvement of the already existing methods of treating wastewater from galvanic production.

At the moment, process equipment does not fully utilize the chemicals used for cleaning and neutralizing the heavy metal ions in wastewater, such as acids, alkaline and rinse water.

In addition, the increase in volume of sludge and sediment significantly complicates operation of wastewater treatment plants and leads to increase in energy costs.

Therefore, finding ways to improve the efficiency of wastewater treatment is always relevant. One of the ways to solve this problem is offered by GlobeCore with its electromagnetic nano-mill (AVS). This equipment was developed in the 1960-1970s and is successfully used in many production lines for intensification of processes.

The  effects of electromagnetic treatment, dispersion phase, electrolysis and high local pressure in the chamber of the AVS significantly accelerate the process of wastewater treatment.

Research Department of GlobeCore performed experiments treating wastewater from galvanic production with the AVS-100 laboratory electromagnetic nano-mill. The results of the experiment are shown in Table 1.

Table 1

The results of treatment of wastewater from galvanizing removing heavy metals with electromagnetic nano-mill AVS 100

Parameter

Value

Maximum

permissible concentration (European Union)

Before treatment

After treatment

1

рН

1,75

6,74

6,5-8,5

2

Fe, mg/l

9,7

2,77

2-20

3

Cu, mg/l

18,29

0,65

0,1-4

4

Ni, mg/l

5,8

<0,02 (not detected)

0,5-3

5

Cr+6, mg/l

19,08

<0,005 (not detected)

0,1-0,5

The submitted data shows that the AVS reduces the concentration of heavy metals to values not exceeding the maximum permissible concentration for the European Union. The nickel and hexavalent chromium are completely absent in the treated water. It shows the possibilities of the future use of electromagnetic nano-mills in countries with more stringent regulations for hexavalent chromium and nickel concentrations.

Also worth noting is that the cleaning of wastewater samples was instant and the reagents were used in small amounts. In addition, there was a more intensive sedimentation of sludge compared to the units with conventional stirrers.

Meat Processing Wastewater Treatment

Meat processing wastewater treatment. Rational use of raw materials and energy resources is a major problem of today. It is closely related to the protection of environment and, in particular, the protection and conservation of water resources.

In the 1980s the big meat processing complexes treated their wastewater mainly by mechanical methods. Now a significant number of small and medium enterprises release their practically untreated wastewater into the municipal sewers or into natural waterways.

Such waste dumping into the urban sewers raises the problem of  cleaning wastewater with high content of organic pollutants. These pollutants can not be eliminated by aerobic biological oxidation.

The main difficulty of treating this wastewater is its instability in volume and composition. This instability is caused, first of all, by the different raw animal materials (supplied meat is semi-finished or it is cattle for slaughter and subsequent processing), which, in turn, affects the stages of meat production, and consequently affects the wastewater. Secondly, the instability is caused by a range of products, including quantitative and qualitative composition of the ingredients in meat products. Thirdly, it is affected by the chemical composition of detergents which are used in compliance with sanitary and hygienic conditions in the workplace. Fourthly, the wastewater depends on seasonal fluctuations of demand for meat products in the market.

Traditional wastewater treatment by grease traps, sediment tanks and flotators does not always provide the necessary quality of wastewater treatment. Improving the treatment by using various filtering materials like flexible polyurethane, polystyrene and others, does not always give the expected results, besides, the filter material loses its properties after working for some time in the filtration-regeneration cycles and must be recycled, otherwise it may cause a negative impact on the environment.

High pH of wastewater (11,6-12,4) is unfavorable, and moreover, it is disastrous to the development of microorganisms, making biological methods unsuitable for cleaning such wastewater.

Furthermore, this wastewater is characterized by intense unpleasant odor, which requires prompt deodorizing and special anaerobic biological treatment to separate biogas.

The biogas contains hydrogen sulfide, which is a product of biochemical conversion of proteins. Also, the anaerobic wastewater treatment for meat processing plants takes longer than aerobic.

Wastewater treatment by electrochemical methods requires special equipment and skilled personnel, making it unavailable for small companies

Biological treatment of wastewater. Bioplatо

Bioremediation is a promising treatment of wastewater of different origins. Generally, a wastewater treatment plant is a complex engineering structure. In this article we will examine one such plant: a floating bioplato.

A bioplato is used for post-treatment and treatment of industrial wastewater, utilities, and surface water run-offs. It almost doesn’t require chemical reagents; it involves minimal costs and minimal maintenance.

The “bioplato” technology uses natural processes of self-purification, which occur in aquatic and semi-aquatic systems and are performed  by higher aquatic plants: reed, cane, weed, mace and others.

These plants are responsible for the following functions:

  • Filtering and creating conditions for sedimentation of harmful impurities;
  • Absorption of biogenic elements and organic matter;
  • Accumulation of certain metals and non-biodegradable organic substances;
  • Oxygen saturation of water during photosynthesis;
  • Detoxification of toxic substances.

The main disadvantage of phytotechnologies is the need for large areas compared to the structures for mechanical and chemical-biological treatment, which occupy small areas. In autumn and winter the performance of bioplato is somewhat reduced, but the quality of treatment does not deteriorate and the treated water can be discharged into natural water bodies.

Monitoring the performance of an operating bioplato shows that natural shrubs and higher aquatic plants form a balanced ecosystem and do not require artificial control. The situation is different when using bioplato for industrial wastewater which contains heavy metals and toxins. There is a risk of secondary contamination of water there, and bioplato operation becomes much more complicated.

The main advantages of phytotechnologies are low cost, no electricity, ease of construction and virtually no need for maintenance by operating personnel.

Tannery Wastewater Treatment

Tannery wastewater treatment.. Tannery wastewater is highly concentrated and contains contaminant particles of different size. This is due to a large variety of chemicals in leather industry: sulfuric acid, lime, soda ash, sodium sulfate, sodium sulfide, hypophosphite, ammonium sulfate, synthetic surfactants and finishing agents, kerosene, methyl esters, molasses etc. Synthetic surfactants are used in tanneries as solvents, wetting agents, detergents, emulsifiers, dispersants and accelerators of the processes.

During various operations associated with tanning and shaving hides in preparing leather, all these substances get into the wastewater and into the sewers. In addition, this wastewater contains components of skins, namely collagen proteins, fats and fat-like substances, some minerals containing sodium, potassium, calcium, and other elements. The specific amount of wastewater per 1,000 dm2 production is 2-9,5 m3 (lower values are characteristic for curing of hard skins, and higher are for chrome-tanned leather).

The conventional technologies for treatment of highly concentrated wastewater, particularly from tanneries, have several limitations. Therefore, it is appropriate to improve them using the electromagnetic nano-mills (AVS).

These devices were developed in the 1960s and became known as intensifiers of different processes, including tannery wastewater treatment.

In the chamber of the AVS various processes affect water purification:

  • Intensive mixing and dispersion;
  • Electrolysis;
  • Impact of electromagnetic fields;
  • High local pressure, etc.

Under other conditions these reactions last for minutes and hours, in the AVS they occurs within minutes, even seconds.The AVS used for wastewater treatment:

  • Reduces the consumption of reagents;
  • Reduces the production floor-space, allocated for a wastewater treatment plant;
  • Speeds up the cleaning process;
  • can be implemented into any technological process line.

Removal of Coke and Byproducts From Wastewater

The problem of industrial wastewater treatment to remove dissolved organic matter, such as phenols, is important and difficult at the same time, despite the large amount of domestic and imported equipment innovations.

First, deep purification of wastewater dictates special rules and conditions that are difficult to implement in practice. Second, many effective methods of deep purification require significant resources and costs, the the use of hard to find reagents with subsequent regeneration and recycling of waste. For most businesses this is difficult to perform. Therefore, the search for new effective methods of industrial wastewater treatment is ongoing.

Among the methods of destruction of organic pollutants in effluent the most common are electrochemical, electrocatalytic and reagent oxidation/reduction methods. These methods have certain advantages and disadvantages. The method most widely used is electrochemical destruction of organic substances in wastewater.

After considerable theoretical research, with the development of new low wear anode materials and new equipment designs, this method is quite promising. It uses micro-arc discharge for processing. The effectiveness of this treatment method is due to the high pressure and temperature of the discharge and significant power output.

The success of electrochemical wastewater treatment is based on the right choice of anode material, the design of the electrochemical reactor, energy consumption and the direction and selectivity of electrode processes. Most of anode materials are developed and produced specifically for electrolysis of concentrated sodium chloride solutions. These anode materials are based on RuO2 and IrO2. The platinum-titanium anodes are unsuitable for wastewater treatment. Another major group of anodes made of metal oxides (Co3O4, Fe2O3, PbO2) has high efficiency in the synthesis of sodium hypochlorite, but such anodes are not made industrially. Therefore, electrochemical treatment of wastewater from coke and by-product uses carbon, coke and carbon-graphite anodes. Their availability, ease of application and catalytic activity in low concentrations of chloride make them promising for decomposition of phenols in wastewater from coke and by-products process.

Sorbent wastewater treatment to remove heavy metals

Remove heavy metals. The presence of heavy metal ions such as copper, lead, iron, nickel, zinc in the water is a serious problem for the environment due to their high toxicity, and also due to the inability of microorganisms to process them. The main water pollutants with such metals are ferrous and non-ferrous metallurgy and machine-building facilities.

As a result of outdated technologies, a large amount of industrial pollutants including toxic heavy metals (lead, cadmium, manganese, cobalt, nickel, copper, iron, zinc and others) are discharged into waterways. The total amount of pollution entering waterways and over the surface flow in urban areas is about 15-20%. During the 1990s, the concentration of copper, zinc and lead in waterways increased by 1.5-3 times compared with the 1980s. Even today, the ions of heavy metals pollute water from bottom sediment. Therefore, the problem of efficient extraction of heavy metals requires effective methods for wastewater treatment.

There are many methods of sewage treatment, but each has its own disadvantages. The disadvantage of the extraction method is its complex technological process. The majority of extractants dissolve in the treated water to a varying degree. The disadvantages of the reagent methods are the significant costs of reagents and contamination of wastewater with them, making the water unsuitable to return into the cycle due to its high salinity. The disadvantage of the settling method is a large number of Na+, K+ and Ca2+ ions. The disadvantage of the ion exchange method of wastewater treatment is a low exchange capacity of ion exchangers. For coagulation method it is the generation of non-recyclable waste and low quality of treatment.

Adsorption is widely used for the final deep cleaning of wastewater to remove dissolved organic substances as a post-treatment after biological treatment of wastewater, and also for local treatment if the concentration of organic substances in wastewater is negligible and they do not decompose biologically and are not highly toxic.

The advantages of adsorbers are:

  • Natural sorbents are available in many countries;
  • They are easily obtained;
  • Adsorption technologies provide a high degree of purification;
  • The used adsorbent is utilized in other productions;
  • They do not require regeneration;
  • They can be regenerated.

The efficiency of adsorption treatment is 80-95%, depending on the chemical nature of the adsorbents, their chemical structure and adsorption surface, and their adsorbing ability in water solution. The adsorbents used in  treatment are activated charcoal, synthetic adsorbents and some waste products (ash, sludge, etc.) Non-carbon sorbents of natural and synthetic origin such as clay rocks, zeolites and other materials are also commonly used. The wider use of such sorbents is due to their high exchange capacity, selectivity, ion exchange properties of some of them, relatively low cost and availability.

Each adsorbent has its individual characteristics. For example, glauconite ensures prolonged action and low desorption rate (2-8%), with no need for recycling.

Dairy wastewater treatment

Dairy wastewater treatment . Dairy production is the second largest sector in the food industry. Milk processing plants are spread across the country due to the widespread availability of feedstock. The technology of food production creates large amounts of waste with different contaminants and concentrations. This problem needs to be solved to make dairy industry environmentally clean. It will automatically improve the environmental conditions in the area, because in most cases dairy wastewater is discharged into the sewerage system without any treatment, which can lead to malfunctions of urban sewage treatment plants and reservoirs.

Dairy industry consumes water at approximately 5 m3  for 1 ton of feedstock. The water is used for various processes: for sanitary purposes, as a heating medium (steam), wet washing, etc.

The concentration of wastewater pollution at various dairy facilities varies considerably. The variation is due to a wide assortment of products and fluctuations in output and pollutant content in the wastewater during the day. Also, the pH of wastewater ranges from 5.5 to 8.5, at temperatures from 15 to 35 ° C.

The fat content in wastewater from butter, cream, sour cream factory cold rooms is 200-400 mg/l. Suspended particles are mainly fats and coagulated protein particles. Dissolved particles are organic acids and lactose.

Microbiological contamination of dairy wastewater is low and is represented mainly by microorganisms causing lactic, acidic and alcoholic fermentation.

Despite the significant fluctuations in concentration of pollutants, the wastewater should go through a bio-chemical treatment.

Dairy wastewater treatment should be implemented locally. The primary stage of treatment is biodegradation of organic substances by microorganisms. This method is extremely efficient because it does not leave any by-products, i.e. the compounds are oxidized to carbon dioxide and water.

This principle is traditionally used at urban (municipal) wastewater treatment plants. It can also be used for the treatment of industrial (dairy) wastewater with small amounts of pollutants.

The difficulty of using aerotanks for biological treatment of dairy wastewater is caused by slow metabolization of lactose. The solution to this problem could be an integrated anaerobic-aerobic purification process, which can remove a significant amount of pollutants.

Methane fermentation is used as a preliminary step of purifying concentrated wastewater, followed by a mandatory aerobic treatment. This produces large amounts of biogas (60-80% methane) that serves as an alternative energy source. In addition, methane fermentation of wastewater from food production (including milk) produces a substantial amount of B vitamins and other biologically active substances, which puts a high value on this sediment.

Wastewater treatment of baker’s yeast production plant

Baker’s yeast.. Rational use of water resources and the protection of waterways from wastewater pollution is of paramount importance. The only way to effectively clean the waterways from pollution is to properly treat wastewater (especially industrial), improving the existing physical, chemical and biological treatment methods and developing new methods.

Wastewater from plants producing bakery’s yeast contain organic and inorganic contaminants. They are suspended mineral matter and volatile components, nitrogen, ammonia, phosphorus, sodium, potassium, calcium, etc.

Such wastewater must be purified before it is discharged into waterways or sewage system (if the plant is located in an urban area).

Wastewater treatment now uses methane fermentation. This method is used in the UK, the USA and Japan. This treatment is effective, but it requires significant investment, a lot of chemicals and other industrial water. Therefore it is necessary to justify the cost to use this approach.

Another wastewater treatment for baker’s yeast production plants is aerobic fermentation which also requires expensive equipment. That’s why the wastewater should be first cleaned by methane fermentation, which removes a significant portion of organic contaminants and then by aerobic fermentation. If we combine these two methods, the cleaning effect will be 95%.

After treatment, the water can be used in fisheries, in water rotation system, for irrigation in agriculture, as well as for industrial purposes.

Treating wastewater from electroplating plants

Treating wastewater. Improving environmental safety through development of low-waste technologies, efficient treatment equipment, resource recovery wastewater treatment are the priority directions of the modern industry.

Natural water resources are becoming a critical problem of today, because of outdated industrial water supply processes, poor state of wastewater treatment plants and old wastewater treatment technologies. They all lead to aggravation of the environmental situation. While towns and settlements suffer from the lack of fresh water, industrial plants dump polluted industrial wastewater into the water bodies. One of the biggest sources of pollution are galvanic electroplating facilities. Their insufficiently treated galvanic wastewater pollutes waterways with thousands of tons of highly toxic heavy metals such as zinc, nickel, chromium, and others annually, considerably complicating the environmental situation.

One of the most dangerous is the wastewater containing toxic hexavalent chromium. Hexavalent chromium damages natural environment, poisons water, further contaminates the ecosystem, disrupting the ecological balance.

In order to protect the biosphere from chromium compounds electroplating wastewater is treated with electrocoagulation method, which simultaneously reduces the hexavalent chromium and sediments it in the form of hydroxides. The electrogenerated sediment sludge has a stable form that does not leak into the environment during prolonged storage or when used as a secondary raw material in construction, metallurgy and roadworks. Still, electrocoagulation method is rarely used because of its technological complexity and high cost.

Considering the abovementioned problem of treatment galvanic plant wastewater and the continuing search for new and more effective approaches, GlobeCore designed the AVS electromagnetic nano-mills that are successfully operated in production lines in various industries at the moment.

The intensifying factors in electromagnetic nano-mills are:

  • electrochemical factors, electromagnetic treatment with activation of substances;
  • dispersed phase;
  • geometric parameters and hydrodynamic factors that ensure intensive mixing of the processed media.

We conducted the experiment treating wastewater from an electroplating facility removing heavy metals with the AVS-100 (laboratory unit). The reducing agent used in the experiment was ferrous sulfate FeSO4. The reduction of trivalent and hexavalent chromium with the reagent was performed in an alkaline medium, introducing lime milk Ca(OH)2 into the water.

Because a reducing agent in an alkaline medium is iron(II) sulphate, there is no need to increase wastewater acidity. During the experiment, 10 mg of 10% iron sulfate solution was added into the  0.5 liters of wastewater.

The ferromagnetic particles for processing in the operating chamber of AVS were 20 mm long and 1.8 mm in diameter (total weight 200 g) The treatment duration was 3 seconds.

Table 1 shows the results of treating wastewater from an electroplating plant, removing heavy metals with the AVS-100 electromagnetic nano-mill,  and comparing them with the maximum permissible concentrations according to the European Union standards.

Table 1

The results of removing heavy metals from electroplating wastewater with the AVS-100 electromagnetic nano-mill.

Parameters

Value

Maximum

permissible concentration (European Union)

Before treatment

After treatment

1

рН

1,75

6,74

6,5-8,5

2

Fe, mg/l

9,7

2,77

2-20

3

Cu, mg/l

18,29

0,65

0,1-4

4

Ni, mg/l

5,8

<0,02 (not detected))

0,5-3

5

Cr+6, mg/l

19,08

<0,005 (not detected)

0,1-0,5

The research leads to the following conclusions

1) Treating wastewater from electroplating facilities with the AVS-100 electromagnetic nano-mill reduces the concentration of heavy metals to values ​​not exceeding the maximum permissible concentration for the European Union. A complete absence of nickel and hexavalent chromium in the treated water was achieved. It shows the future perspectives for electromagnetic nano-mills in countries with more stringent regulations for concentrations of hexavalent chromium and nickel.

2) The treatment of wastewater is instant and does not overuse the reagents.

3) Sediment settles quicker than when using stirring devices.

Biological wastewater treatment to remove nitrogen and phosphorus compounds

Biological wastewater treatment. Wastewater treated with traditional biological methods contains large amounts of leftover biogenic substances (nitrogen and phosphorus compounds), which cause a lot of damage in natural water bodies.

The rapid growth of algae in the water causes secondary water pollution, intense coloration and reduction of oxygen concentration. Blooming water greatly complicates its use as drinking water for residences and industrial facilities. Therefore, the content of biogenic substances in wastewater is strictly limited.

There are many methods for wastewater treatment to remove biogenic substances: physico-chemical, biological, and chemical methods. The most efficient and inexpensive is the biological method for removing nitrogen and phosphorus compounds.

Biological purification of wastewater from nitrogen compounds is based on nitrification and denitrification. The essence of these processes is the oxidation of ammonia to nitrate (nitrification) and subsequent reduction of nitrates to nitrogen gas (denitrification). The nitrates containing oxygen reduce the amount of air needed for aeration of wastewater and, as a result, reduce the energy consumption.

The biological treatment of wastewater from phosphorus compounds is based on the ability of certain groups of bacteria (predominantly Acinetobacter) to remove significantly more phosphorus from the liquid phase in artificially created extreme temperature conditions (changing bacteria from anaerobic to aerobic). This process is also called “phosphorus absorption”.

Aerotanks can increase phosphorus removal rate by combining biological methods with chemical sedimentation.

Industrial wastewater treatment from lead

Industrial wastewater. Wastewater containing lead is extremely toxic. This metal is hazardous and has toxic and mutagenic effects on living organisms.

It has an extremely negative effect on the human reproductive system. For these reasons, the presence of lead is strictly limited in the wastewater of industrial facilities. When industrial wastewater is discharged into municipal sewage systems, the maximum permissible discharge (MPD) of lead should not exceed 0.1-0.05 mg / dm3, and the discharge into waterways should be less than 0.03 mg / dm3.

Industrial wastewater does not always contain lead. Significant concentrations of lead come from the production of sliding bearings and crystal glass.

Such wastewater contains many different metals and pollutants that are difficult to extract. The wastewater from sliding bearings production contains heavy metals (copper, zinc, nickel, tin), a wide range of organic impurities, particularly alkylsulfonic acid and a mixture of surfactants. The wastewater from crystal glass manufacturing contains glass colloidal particles and glass grinding pastes, as well as zinc and organic compounds. Thus, the wastewater from these processes are characterized by significant fluctuations in the concentrations of contaminants and the pH value.

Lead ions could be precipitated with the help of reagents in water solution in the form of hydroxides, sulfides and carbonates. Since lead hydroxides have a significant solubility (S = 1,0-0,95 mg/dm3), it is recommended to precipitate them in less soluble compounds as basic carbonate or lead sulfide.

Modern chemical methods of wastewater treatment are characterized by high consumption of reagents, complex treatment facilities and long duration of the process.

GlobeCore offers the AVS electromagnetic nano-mills for the industrial wastewater purification from lead. They were developed in the 1960-1970s. Even then they showed excellent results in the intensification of different technological processes.

Experiments confirmed the efficiency of the AVS for purification of wastewaters of different origins, which was achieved due to a number of effects and processes occurring in the operating chamber of the unit: the impact of electromagnetic field, electrolysis, intensive mixing, acoustic impact etc. The chemical reactions, which in traditional equipment would last minutes or hours,  only last seconds or tens of seconds in the AVS.

The unit is compact and can be integrated into virtually any existing wastewater treatment line. With proper placement (serial or parallel) of multiple units, the processing rate is virtually unlimited.

Methods of chromium and heavy metals removal from wastewater

Heavy metals removal from wastewater. In recent years, the most widely used methods of wastewater treatment to remove chromium and heavy metals are chemical (reagent), ion-exchange and electrochemical.

Wastewater treatment with reagents

Reagent treatment of wastewater is based on the use of reducing agents for chromium purification and precipitation agents for heavy metals neutralization. The reagent treatment of chromium containing wastewater restores the hexavalent chromium to trivalent and precipitates it. The reducing agents are sulfur (sodium sulfite, sodium bisulfite) copperas, scrap steel  and others.

In practice there are  two methods of wastewater treatment to remove chrome:

  • Reduction of Cr6+ to Cr3+ in acidic medium followed by precipitation of Cr3+, together with other heavy metals, in an alkaline environment, and neutralization of wastewater;
  • Joint treatment of chromium containing and acid-alkaline wastewater in an alkaline environment with reduction of Cr6+ to Cr3+ with copperas and precipitation of heavy metals.

Assessing the opportunities and prospects of reagent treatment methods, their shortcomings should be considered: the insufficient purification from heavy metals, high salt content, which often prevents reuse of purified water in the cycle; high consumption of reagents, large amounts of sediment and its high humidity, complex and bulky metal equipment with large footprint.

Ion exchange methods for wastewater treatment

One of the promising methods of wastewater treatment is ion exchange. This method provides an almost complete removal of harmful impurities from wastewater and allows the water to be reused. But it has limitations in treating wastewater from salts of heavy metals. Ion exchange can be used for purification of wastewater with salt content of up to 2.3 g / dm3 and  small amounts of metals and acids. The process is also complicated and the reuse of the concentrated solutions after regeneration is impossible too. The essence of ion exchange is the ability of cation and anion to exchange their ions for cations and anions and adsorb them from wastewater. At the same time, ion-exchangers must meet the following requirements: have a high exchange capacity, resistance to acids, alkali, oxidants, and perform as reducing agents, be insoluble in water and electrolyte solutions, have little change of volume.

This method is used in circular water systems at industrial facilities. It reduces freshwater consumption in the production process and in electroplating process, but it occupies a larger production area (1.5-2 times). The ion exchange method also has the following disadvantages: it uses large amounts of expensive reagents (3-4 times more than theoretically necessary), extra costs for regeneration of ion exchangers and decontamination of regeneration products, the costs of significant amounts of water, a large amount of mineral salts getting into the water bodies with neutralized regeneration products. The use of this method is also limited by the considerable costs, shortage of equipment and ion exchange resins, and it should only be used where there is a need for desalinated water.

Electrochemical methods of wastewater treatment

Recently, the electrochemical treatment of wastewater to remove chromium and other metals using steel electrodes has become very popular. Its essence lies in the chemical reduction of chromate ions due to electrochemical processes and electrolytic decomposition of water and oxygen and hydrogen evolution reaction. Simultaneously hydroxide and iron hydroxide,  chromium and other metal hydroxide bond the OH groups during electrolysis.

The analysis of physico-chemical characteristics of the electrochemical cleaning method points to its complexity. This method has the following stages: chemical ionization and electrochemical dissolution of iron, the reduction of hexavalent chromium to trivalent chromium and iron, the formation of basic salts and hydroxides of metals and their precipitation. The processing rate of electrochemical treatment depends on pH, current density, treatment duration and other factors. At the same time, the recommendations and the parameters of treatment processes are quite diverse, which makes it difficult to design wastewater treatment plants.

We can recommend the equipment necessary to improve the efficiency of existing methods of wastewater treatment to remove chromium and heavy metals.

Methods for water waste treatment for the production of edible oil

Water waste treatment. Rational use of raw materials and energy resources is an urgent problem of today. It is closely related to the protection of environment, and water resources. The large amounts of highly concentrated wastewater come from the food industry. Such water in municipal drainage system or discharged directly into the environment can pose a serious threat to natural waters. The worst wastewater treatment problems belong to the butter, margarine and mayonnaise production. It is due to the high concentrations of grease in these products and inefficient technologies for degreasing of wastewater.

Edible oil is produced by washing raw oils and fats, generating acidic wastewater with high content of organic components (fats, oils and the like). The other type of wastewater comes from washing equipment and transport. All wastewater varies in content and pollutant composition.

The complexity of the cleaning system for such production depends on a variable composition of wastewater. It should take into account that organic compounds disintegrate rapidly, causing acid fermentation and decay.

Enterprises neutralize their average wastewater with sodium hydroxide to a neutral pH, and then pass it through gravel before discharging it into the environment. This kind of treatment is ineffective, since it virtually does not trap pollutants and pollutes the environment with highly concentrated vegetable fat wastewater.

Wastewater of edible oil production is diverse both in component composition, and in concentration. It is a complex physical-chemical system with dissolved organic matter and disperse particles of varying fineness that require complex cleaning methods.

The particles may be removed by the simple methods of settling and filtration.

The organic substances can be removed only by a chemical or biochemical methods.

The processing rate of a biochemical method (biodegradation of contaminants in the wastewater) depends on water nature, dispersity and concentration, but biodegradation requires more time than chemical purification. Also, the wastewater can be purified by adsorption methods, using polytetrafluoroethylene, activated carbon and clay as adsorbents.

For best results, oxidants are introduced into the system. They gradually destroy organic structures. These oxidizing agents include solutions of sodium hypochlorite, bleaching powder, chlorine and its oxides. However, these methods are effective only for low concentrations of organic pollutants and are mainly used in the final stages of cleaning.

Chemical methods are based on the introduction of chemical reagents into the system. They serve as binders for organic soluble compounds resulting in precipitation of heavy organic acids. Such chemical agents may be acids, bases, and iron salts. For better sedimentation of inorganic coagulants A12 (SO4) 3, FeSO4, Fe2 (SO4) 3 or flocculants are also added.

For separation of suspensions electrocoagulation and electroflotation are also used.

Electroplating wastewater treatment – chemical methods

Electroplating wastewater. Wastewater from electroplating and printing plates is classified as acidic or alkaline metal containing wastewater. Therefore the treatment includes methods that neutralize acids and alkali, extract metals, but do not extract organic contaminants. As a result, there is a difficulty to extract metal organic complexes. It should also be noted that certain organic impurities in the electroplating wastewater have enhanced toxicity.

In the copper, nickel and chromium electroplating processes, sulfite-thiocarbamide electrolytes , sulfurol, naphthalene, polyacrylamide, monosaccharides condensation products or polysaccharides, amine derivatives etc are added. These electrolytes produce organic decomposition products that enter the polishing paste.

Research shows that the solution is a closed cycle “etching-regeneration” process in a single stage. At the same time, this wastewater is not properly researched, reliable design and technology, which could extract organic impurities for the reuse of these waters in the same production have not been developed.

The known chemical purification methods include treatment with an oxidizing agent (concentrated acid with a catalyst, ozone, agents containing active chlorine)  under normal conditions lead to incomplete oxidation and the chemical oxygen content higher than permissible standards of discharge into sewers. To increase the degree of purification the temperature of the process is raised to120-200°C with the use of aluminum oxide catalysts. The most efficient way with simple equipment design of is direct electrochemical oxidation of organic substances.

It is important to consider that organic substances form complex compounds with metals transferring the metal into complex compounds.

Also worth noting is the impact of organic substances on the chemical recovery process, the nature and concentration of anions in solution.

The analysis of the intensifying factors in the electromagnetic nano-mill (AVS),  that have significant effect on wastewater treatment are:

  • electrochemical and electromagnetic factors;
  • dispersing;
  • hydrodynamic factors for intensive mixing.

The electromagnetic nano-mill AVS-100 (laboratory scale) was used in electroplating plant wastewater treatment from heavy metals. The reducing agent used was iron sulfate FeSO4 that reduced hexavalent chromium into trivalent chromium, with introduction of lime milk Ca(OH)2.

In the reaction, 10 mg of 10% iron sulfate solution were added into 0.5 liters of water.

The ferromagnetic particles used for processing were 20 mm long and 1.8 mm in diameter (total weight 200 g). The time for  treatment took only 3 seconds.

Table 1 shows the results of removal of heavy metals from electroplating wastewater with electromagnetic nano-mill AVS 100, and a comparison of the original values and maximum allowable concentrations, valid for the European Union.

Table 1

The results of removing heavy metals  from electroplating wastewater with electromagnetic nano-mill AVS 100

Parameters

Parameter value

Maximum allowable concentration (European Union)

Before treatment

After treatment

1

рН

1,75

6,74

6,5-8,5

2       Fe, mg/L

9,7

2,77

2-20

3

Cu, mg/L

18,29

0,65

0,1-4

4

Ni, mg/L

5,8

<0,02 (not detected)

0,5-3

5

Cr+6, мг/л

19,08

<0,005 (not detected)

0,1-0,5

This study draws the following conclusions:

1) The electromagnetic nano-mill AVS-100 for wastewater treatment from electroplating facilities reduces the concentration of heavy metals to values not exceeding the maximum permissible concentration of the EU, and also achieves complete absence of nickel and hexavalent chromium in the treated water. It shows the promising application of electromagnetic nano-mills in the countries with tough regulations for hexavalent chromium and nickel concentrations in water.

2) Water treatment is instantaneous and saves reagents.

3) Sediment settling is much faster than with a stirring device.

Municipal wastewater treatment

Municipal wastewater treatment has become a complex process, due to numerous industrial facilities located in and around settlements, making their wastewater highly irregular in composition. Industrial wastewater requires a combination of the existing methods and improvement of the whole treatment process. The main approaches that can be used in municipal wastewater treatment plants are discussed below.

Mechanical treatment is used for cleaning of virtually all wastewater. Its essence is clarification, sedimentation, filtration and centrifugation. These methods allow to remove up to 60-80% of impurities contained in the wastewater in undissolved and partly colloidal state.

Biological wastewater treatment is considered to be one of the simplest and the most accessible method. It is based on the natural ability of ecosystems to recycle the substances by microbes. Biological treatment can remove the smallest suspended solid particles which remain in the wastewater after mechanical treatment.

Chemical treatment is the removal of contaminants by chemical reactions. These reactions begin with the introduction of special substances acting as reagents into wastewater. A good example is the oxidation-reoxidation reaction which causes precipitation of contaminants for filtration.

Physico-chemical methods of treatment are adsorption, crystallization, flotation, extraction, coagulation and others.

Neutralization of wastewater is another method, which can be performed by using one of the following techniques:

  • Mixing of acidic and alkaline wastewater in equalization tanks;
  • Mixing wastewater with reagents in balancing tanks;
  • Filtration of wastewater through various materials (dolomite, marble, limestone, etc.).

Using Chemicals to Remove Chromium from Wastewater

Remove chromium. The most common methods of wastewater treatment are reagent treatment, ion exchange treatment and electrochemical treatment. Chemical reagent treatment is most common method of chrome and heavy metals removal.

This method of treatment is based on the reactions of chemical reagents with pollutants. In case of chromium-containing wastewater, the reagents reduce hexavalent chrome to trivalent chrome followed by its precipitation. Some of the reducing agents are:

  • copperas;
  • sulfur compounds (sodium bisulfite, sulfite, etc.);
  • scrap steel;
  • scrap iron.

In practice, there are two approaches to purification of chrome containing wastewater. In the first approach hexavalent chrome is reduced to trivalent chrome in acidic environment followed by neutralization and precipitation. The other method is combined treatment of chrome and acid-alkaline wastewater in alkaline environment, with the parallel reduction of chrome by copperas. The process is completed by precipitation of heavy metals.

Obviously, wastewater treatment is not complete with the removal of chrome. It is also important to remove other heavy metals by neutralization with alkaline reagents. The best results are achieved by combined wastewater treatment removing several metals rather than removing each one separately.

In many facilities, the chemical treatment of wastewater by alkali is enough to reduce the content of heavy metal ions to values allowing wastewater discharge into the municipal sewage system. Deeper purification is achieved by post-treatment of wastewater through the ion-exchange filters.

Overall the chemical reagent wastewater treatment has both advantages and disadvantages. The disadvantages include insufficient degree of heavy metal removal, a high content of salts in the purified water, unrecoverable loss of metals, high reagent consumption, complexity and bulkiness of equipment.

As it is not possible to develop fundamentally new methods of wastewater treatment that do not use chemicals at the moment, improving the existing approaches is the solution.

One of the most promising ways to improve the treatment process is to use the electromagnetic nano-mill (AVS). The chemical reactions in the chamber of this device occur much faster: in seconds and fractions of a second. This is due to a number of effects, such as electromagnetic field effect, intensive dispersion and mixing and electrolysis.

The AVS reduces the consumption of reagents, reduces the footprint of equipment and significantly reduces the duration of wastewater treatment.

Adsorption treatment of wastewater containing dyes

Treatment of wastewater. Large amounts of wastewater contain various dyes which are toxic and hazardous for the environment. This wastewater comes from the dye manufacturers and dyeing facilities of various industries.

Harmful substances get into the water reservoirs with wastewater, degrading their sanitary state and requiring special treatment of water before its use for domestic and industrial needs. The water goes through mechanical treatment where the contaminants and impurities are removed from the water, and neutralized with biological treatment, then extracted by such conventional purification techniques as settling, coagulation and flotation. At the end of this complex comprehensive water treatment process there is adsorption aftertreatment. As a rule, it is the final step of water purification.

The adsorption methods use non-carbon sorbents of natural and artificial origin for water purification. These sorbents have a sufficiently high adsorption capacity, selectivity, cation exchange properties, and are available at relatively low cost. The most widely used mineral natural sorbents are zeolites and clay materials. They are characterized by a variety of features and are constantly expanding the boundaries of application for water purification.

Treatment of wastewater. The theoretical ion exchange capacity of natural zeolites ranges from 2,6-5,8 mEq / g. That’s why natural zeolites are greatly used as ion exchangers and sorbents for purification of natural and wastewater, especially such materials as clinoptilolite and mordenite.

A well known chain structured mineral with sorption properties is palygorskite. Its adsorptive properties are defined by the zeolite channel structure (primary pores) with long and short fibers (secondary pores).

Bentonite is a clay mineral (consisting mainly from montmorillonite and beidellite) with varying degrees of absorption properties. Bentonite is not heat-resistant, it has low catalytic and adsorbent activity that requires acidic activation. Bentonite clay activity is determined by its cation exchange capacity, its crystalline structure of montmorillonitic type and bound water. When the bound water is removed at high temperature it leads to the destruction of the crystalline structure and loss of activity. Acid activates bentonite adsorption and catalytic properties, but generally degrades its physical strength. Therefore, the use of acid-activated bentonite is limited by clay contacting purification technology.

Industrial wastewater treatment – electrochemical methods

Industrial water treatment plant. The electrochemical method of wastewater treatment is primarily used for extraction of chromium.

The chromium is removed by sedimentation and by electrolysis with iron anodes.

The process is based on the oxidation of trivalent to hexavalent chromium at the anode. The solution is pumped through electrolytic cell. The electrodes (anode / cathode ratio is (30/1) are energized with direct current. This electrochemical process keeps the concentration of trivalent chromium in the range of 60-75 g / l and hexavalent chromium concentration of 1069-1137 g / l. This technology allows multiple reuse of chromic acid. But with all its appeal (heavy metals come in pure form, no septic tanks or bulky chemical plant needed) this electrolysis method is not widely used, as the metal is obtained in powder form and requires additional processing for recycling. More promising is the method of direct electrolysis for recycling the recovered metal from draining solution.

Since the chromium effluents, apart from chromium (III, VI), also contain iron, copper, lead and zinc, complete purification requires extraction of these metals. For this purpose reagent method is used. However, this method does not provide a high degree of purification because of its inability to simultaneously sediment all metals in the effluent.

Ways to Improve Industrial Wastewater Treatment?

industrial wastewater treatment

Industrial wastewater treatment. The environmental issues of industrial wastewater treatment are becoming more and more important. This is due to the growing  pollution of water and air with the continuous increase of industrial wastewater volume and the tremendous growth in clean water consumption. This demands the development of new effective methods and equipment for water purification.

Experts estimate that  since 2000 the wastewater discharge in the US and Germany exceeded hundreds of millions of tons per year .

Such scale of industrial wastewater generation and the growing rate of water consumption need to be addressed by finding solutions in clean and uninterrupted water supply.

For example, chemical industry wastewater poses a significant risk to the environment, and the urgent problem is the development of efficient equipment for wastewater treatment.

The research of domestic and foreign equipment showed that the most promising are the electromagnetic nano-mills (AVS).

These devices can be installed in new and existing process lines. The processes and effects that occur in the chamber of the AVS unit provide a more efficient treatment of wastewater:

  • Vigorous stirring;
  • Dispersing;
  • Electromagnetic acoustic processing;
  • Electrolysis.

Application of the AVS in industrial wastewater treatment reduces the amount of reagents used, reduces the footprint of treatment facilities, and speeds up the reaction proceeds.

GlobeCore successfully tested the AVS-100 and AVS-150 units in treatment of wastewater of different origins.

Contact us at one of our contacts and we will advise you on retrofitting the AVS in existing treatment lines, or creating a new treatment facility based on the AVS unit.

Wastewater treatment plant process in paint production

wastewater treatment plant process

Wastewater treatment plant process. Wastewater treatment, reuse and disposal is a pressing environmental, economic and technological  problem for many industrial facilities. The current methods often do not provide complete water purification and do not meet modern environmental standards. Formaldehyde paint shops wastewater (FSV) forms a waste of phenol, urea or melamine with formaldehyde.

Phenol resins are polycondensation products of phenol with formaldehyde.

Urea-formaldehyde resins modified with butyl alcohol are used for urea-alkyd paint production. Melamine-formaldehyde resins modified with alcohols are the basis of a melamine-alkyd paints.

Wastewater of paint formaldehyde productions is a complex multicomponent formation contaminated with organic and inorganic substances in dissolved, colloidal and coarse-grained dispersion states and may contain formaldehyde mass concentration of 50-3000 mg / dm3.

The maximum allowed concentration (MAC) of formaldehyde in fishery waters is 0.25 mg / dm3, so prior to discharge into sewer drains the wastewater must be thoroughly cleaned.

Wastewater treatment plant process. Deep wastewater purification removing formaldehyde is performed by biochemical oxidation. This process is based on adding strong oxidants into the system (hydrogen peroxide, potassium permanganate, etc.), and oxidation at high temperature and pressure (with significant operating costs), it also requires the construction of large and expensive structures, which  return their costs only after processing significant amounts of wastewater.

The application of reagent methods has disadvantages, such as high costs of transportation, storage and dispensing of reagents, not to mention the usual high cost of the process.

Traditionally the methods of wastewater treatment are: biological, chemical and physico-chemical. The biological treatment is used for wastewater with concentrations of formaldehyde of 800-1500 mg / dm3, and can not be applied with high concentrations of formaldehyde, which is toxic to the processing microorganisms and requires the construction of large size and expensive structures.

Among the physicochemical and chemical methods, thermal (incineration), oxidation and absorption methods, and methods of condensation of formaldehyde with an alkaline reagent are the most commonly used. Non-catalytic incineration is applicable only in case of highly concentrated wastewater (15% formaldehyde). Using environmentally hazardous oxidants in oxidizing methods raises the question of separation of the remaining hazardous reagents from the wastewater. The use of many oxidants is also limited by their high cost and the possibility of secondary toxic reaction products.

Absorption methods are free from the above mentioned limitations, but are effective only in a narrow concentration range (300-400 mg / dm3 formaldehyde) and require the disposal of adsorbent or its regeneration.

Improving the efficiency of wastewater treatment plant process in paint production

The electromagnetic nano-mill (AVS)  is an inductor with a hollow active chamber containing ferromagnetic particles. When power is applied, the ferromagnetic particles begin to rotate  in the electromagnetic field.

These devices were designed in the 1960s-1970s and have been successfully used as intensifiers of different technological processes. Another application of the AVS is the wastewater treatment processes. The  rapid physico-chemical wastewater treatment is achieved through intensive mixing, dispersing, acoustic and electromagnetic treatment, electrolysis and other factors. The same processes that last minutes and hours in the stirring devices, occur within seconds or tens of seconds in the AVS.

Moreover, the introduction of AVS units into the wastewater processing lines of various designs reduces the use of reagents, and also reduces the production floor space and optimizes energy consumption.

Aerotank – a biological wastewater treatment facility

aerotank

Aerotank is a tank in which wastewater contaminants go through aerobic oxidation under the influence of activated sludge organisms. The aeration tank is constantly supplied with air that provides for the normal activity of organisms and maintains the sludge in suspension. The sludge is a biocoenosis of organisms that can oxidize  and adsorb on their surface the organic matter of wastewater forming compact medium-sized flakes.

The process of biological treatment of wastewater in the aerotank is divided into three stages. At the first stage the wastewater is mixed with the activated sludge, with the following adsorption of contaminants and oxidation of substances that easily oxidize. This treatment reduces contamination by 40-80% with the total consumption of dissolved oxygen. It usually lasts 0.5-2 hours.

The second stage involves oxidation of substances that oxidize slowly, followed by the regeneration of the activated sludge by adsorbing organic pollutants from it. The rate of oxygen consumption in this stage is significantly lower than in the first stage.

The third stage involves nitrification of ammonium salts. Oxygen consumption rate increases again.

The term “active” means that the biomass is an activated sludge:

  1. It represents microflora with the enzyme systems required for degradation of contaminants.
  2. It has a high adsorption surface.
  3. It forms stable floccules which are easily precipitated and settled.

The aerotank effectiveness is measured by the degree of decontamination, the output of activated sludge, the air flow or energy consumption for aeration, aeration time and sludge concentration etc.

Sedimentation water treatment in the cement industry

sedimentation water treatment

Sedimentation water treatment. Municipal and industrial wastewater goes to the wastewater treatment plants where it is purified and the waste is dried and disposed of.

First the wastewater goes through a preliminary treatment that consists of solidification, stabilization, conditioning, destruction of colloidal structures of sediment and dehydration.

The first step of wastewater treatment is filtering with removal of large particles by passing the water through nets and smaller particles through the screen of the filters. It is followed by clarification and settling of sludge. These processes remove about 50-60% of suspended solids, and the deposited sludge contains a substantial amount of organic matter.

Sedimentation water treatment. Then, the wastewater is subjected to secondary and tertiary treatment (biological treatment), with introduction of the aerobic (or anaerobic) microorganisms that feed on the remains of organic suspended solids, destroying them. Thereafter the wastewater goes into the secondary settling tank  where it deposits 90% of organic matter. Dehydration and drying of the settled sediment requires further energy costs. The process of drying can be performed by the clinker heat and the rotary kiln gases. The whole alternative fuel on the basis of sewage sludge was created for the cement and energy industry in Poland.

The resulting sediment can be used as fertilizer, fuel, heat or electricity, capable of replacing similar traditional products.

In the firing of Portland cement clinker the dried sediment is used as an alternative fuel and burned together with coal. Maximum sediment flow rate must not exceed 5% of the capacity of clinker production.

Wastewater treatment technologies in bakeries

wastewater treatment technologies

Wastewater treatment technologies. The situation with wastewater of bakery facilities varies and depends on the location of the plant. Large factories dump their wastewater into the municipal sewage system, because it is believed that bakeries do not need their own treatment facilities, as their wastewater standards are close to sewer discharge norms. However, this is not quite true. The amount of chemical oxygen consumption of bakery production ranges from 300-600 mg O2 / l, and during the cleaning of equipment it is even higher, reaching 1800 mg O2 / l. Given that the municipal treatment facilities cannot cope with the growing amount of wastewater and the degree of contamination, sooner or later, the sewage discharge standards for sewage system will become tougher. It means that the manufacturers will have to solve these issues locally.

Today, large urban bakeries are addressing these problems. But it is another thing with many small bakeries, located in cities where there are no sewage treatment plants. The amount of wastewater of these facilities is insignificantly small, within 30-50 m3 per day. Therefore it is easy to build a treatment plant for such volume at a bakery.

Wastewater treatment technologies

Since the wastewater of the bakeries contains yeast,  the proposed technological treatment diagram is shown in Figure 1.

Fig. 1. Process diagram of wastewater treatment for bakeries: 1 – electromagnetic nano-mill (AVS); 2 – mass transfer column; 3 – equalizing tank; 4 – pump; 5 – settling tank; 6 – tap ; 7 – regulating valve 8 – sampling tap.

The operating principle of the unit is as follows. The wastewater from the tank 3 is pumped by a pump 4 through valve 6 and the regulating valve 7 goes into the electromagnetic nano-mill (AVS) 1. The air blower supplies air to the AVS. The equalized wastewater is pumped into the AVS activation chamber where it is subjected to the rotating electromagnetic field, the high local pressures, acoustic vibrations, electrolysis, and other factors that intensify the process. After AVS the water enters the mass transfer column 2 for further intensive treatment and effective oxidation. The purified water after the column is collected in a settling tank 5. The samples of clarified water are taken from sampling tap 8 .

Improving the efficiency of industrial wastewater treatment

industrial wastewater treatment

Industrial wastewater treatment. The new ideology of using nature and natural resources is making it a number one priority to solve the environmental and economic problems, to stabilize and improve ecological conditions and protect all types of natural resources. These tasks could be solved by implementing a competent environmental policy and environmental management by changing the patterns of production and consumption, structurally modernizing wastewater treatment plants, and improving drinking water quality.

As you know, the human need in water is enormous and is increasing every year so much, that it has already become a global problem. The issue of water supply is faced by many countries in the world. Even the most developed regions may experience a lack of good drinking water that encourages them to look for ways and means to solve the problem. At present, the promising directions are: rational use of water, better recovery of freshwater resources; development of new technologies to prevent pollution of waterways; and effective methods of treatment of ground water and wastewater.

The existing wastewater treatment methods in many cases comply with the requirements, but at the same time they have a number of disadvantages, such as:

  • High consumption of reagents;
  • Long duration of the cleaning process;
  • Large treatment equipment footprint;
  • Energy-intensive process, etc.

Industrial wastewater treatment. Electromagnetic nano-mill (AVS)

Most of these issues can be solved by cleaning wastewater with the electromagnetic nano-mill (AVS). This equipment appeared in the 1960s-1970s and showed excellent results, intensifying different technological processes.

GlobeCore performed industrial tests of commercial AVS-100 and AVS-150 mills treating wastewater to remove chromium and other heavy metals, and contaminants, including  phenol, arsenic and fluorine.

The effects of dispersion, electromagnetic fields and electrolysis that occur in the working chamber of the AVS, significantly reduce the duration of wastewater treatment (the reaction in the unit lasts seconds and fractions of seconds) and also reduce the amount of reagents used. The units are compact and can be integrated into a serial, parallel manufacturing production lines to achieve the desired performance.

Oil wastewater treatment on board ships and in ports

oil wastewater treatment

Oil wastewater treatment. Oil waste represents a great danger to waterways. It often spills into the environment in the form of liquid petroleum whenransported by sea, causing pollution.

Most modern ships have special equipment that processes oil  contaminated water. The process of cleaning water and removing oil generates waste, sent to offshore or port facilities. As you can see, existing solutions are not autonomous, and require fuel reserves for transportation, as well as finances

The use of wastewater treatment plants on site eliminates these shortcomings, as well as reduces the demurrage of ships in port.

Oil wastewater treatment. Electromagnetic nano-mill (AVS)

Wastewater containing oil can be purified by physical, chemical or biological methods. A combination of these methods gives better results, using heavy and bulky equipment for treatment with high operating costs. Another solution is offered by GlobeCore, the electromagnetic nano-mill (AVS) for oil-containing wastewater treatment at ships and port facilities.

These devices were developed in the 1960s-1970s as activators and enhancers of various technological processes. But unfortunately, they have not received widespread acknowledgement, due to the lack of full scientific explanation of the physical processes that lie in the base of their operation.

When viewed in the context of wastewater treatment the AVS provides:

  • Intensive mixing using hydrodynamic factors, and geometric parameters
  • Electrochemical and electromagnetic activation of substances;
  • Phase dispersion.

GlobeCore commercially produces electromagnetic nano-mills AVS-100 and AVS-150 and has successfully tested this equipment in treating wastewater of various origins.

Compared to the existing equipment for oil containing wastewater treatment on board ships and in ports, AVS has the following advantages:

  • Low weight and small dimensions;
  • The ability to adapt to any pumps;
  • A wide processing rate

Wastewater Treatment with Vortex Layer Device

Wastewater Treatment

Wastewater Treatment. Over the years, there has been a growing anthropogenic impact on water resources. The main reason is the careless attitude of man to nature, resulting in increasing concentration of pollutants in the water every year, unauthorized dumping of washing water from ships, as well as accidental discharges from industrial wastewater from plants.

During the reception of cargo, a ship’s compartments are washed with water that is dumped back into the sea with residue that constitutes a significant threat to all living things. This contaminated water has a high content of nitrates, heavy metals, petroleum compounds and other harmful substances that are absorbed by plants and ultimately end up on the dinner table. Water recourses laws and regulations cannot fully govern business due to insufficient financing or lack of scientific research.

Still, the anthropogenic impact on water bodies is constantly growing due to the lack of purifying equipment at industrial facilities and the lack of modernization of sewage treatment plants. No one can deny the need for rational use of natural resources, especially water.  But we still pollute these recourses with various toxic and harmful substances. The harmful emissions get into air and water from different processing plants.

Wastewater treatment can solve the problems listed above. But the existing methods of treatment are expensive, time-consuming,  labor-consuming and take large production space.

The solution is to use a vortex layer device (AVS) by GlobeCore.

The AVS consists of an operating chamber (tube) positioned in the inductor which creates a rotating electromagnetic field. Inside ​​the tube are small ferromagnetic particles.

The analysis  of the intensifying factors which occur inside the chamber (intensive mixing and dispersing of the processed components, acoustic and electromagnetic factors, local high pressures and  electrolysis) shows their great effect on the wastewater treatment process:

  • The geometrical parameters and operation modes, hydrodynamic factors- ensure intensive mixing of the processed medium;
  • Electrochemical factors and electromagnetic treatment and activation of substances in vortex layer;
  • Phase dispersion.

For example, with the introduction of the AVS into treating of wastewater from heavy metals it is possible to achieve high-quality purification. Reagent consumption is no more than 90-100% of the stoichiometric, which greatly simplifies the operation of wastewater treatment plants. The classic reagent methods use reagents in the amount of 115-120% and 150-175% of reducing agent.

In the simultaneous cleaning of acid-alkali and chromium-containing wastewater the AVS decreases the level of impurities below the allowable concentration, reducing the reagent consumption by 1.5-2 times, lowering the energy consumption 2-ce and reducing the occupied floor space by 10-15 %.

Decontamination of Wastewater

Decontamination of Wastewater

Decontamination of Wastewater. Protection of drinking water, as well as surface and underground water bodies from pollution is a serious problem of humanity, because the need for clean drinking water is always growing.

Water bodies contain naturally occurring impurities along with chemical pollutants of various compositions (pesticides, phenols, petroleum products, heavy metal salts, nitro compounds, etc.), which enter water bodies with insufficiently treated industrial and domestic wastewater. The technologies and equipment currently used for wastewater treatment do not always provide the required level of cleaning and decontamination.

The methods of wastewater decontamination are divided into the following groups:

  • Chemical (using various chlorine compounds, ozone, hydrogen peroxide, organic polymers and other biocides);
  • Physical (thermal, electrical, electromagnetic);
  • Physicochemical (flotation, coagulation, electro filtration, adsorption);
  • Decontamination in artificial and natural biocenosis.

Decontamination of Wastewater. European countries are abandoning wastewater treatment with chlorine, preferring treatment with ultraviolet light, ultrasound and various combined methods.

Today, Germany, the UK and the US almost completely abandoned the use of chlorine. Chlorine-containing reagents have a number of significant faults. Chlorine interacts with organic substances contained in wastewater and forms chloroform, carbon tetrachloride, bromodichloromethane, dibromochloromethane and benzopyrene which have mutagenic and carcinogenic effects. A small dose of active chlorine of 365 mg / dm3 at 30 minutes in some cases is not sufficient for disinfection of wastewater. Using higher doses of active chlorine is unsafe. Furthermore, the use of chlorine requires safe storage and transportation.

Decontamination of Wastewater. The twentieth century studies have found that bacterial and viral microbial flora in wastewater is completely removed only with active chlorine dose of 15620 mg / dm3 in two hours.

The experiments in disinfection of wastewater from polioviruses with the help of chlorine, chlorine dioxide and ozone showed the best results with chlorine dioxide compared to chlorine.

The advantages of chlorine dioxide as a disinfectant in comparison with chlorine are as follows:

  • Oxidizing ability of chlorine dioxide is higher than that of chlorine;
  • Biocidal activity of chlorine dioxide is higher than that of chlorine at the same amounts of reagents;
  • Properties of chlorine dioxide are not dependent on the pH of water;
  • Chlorine dioxide reacting with ammonia and amines does not form chloramines and toxic byproducts of chlorination (trihalomethanes);
  • Organic oxidation products oxidize and do not create danger when released into the natural water bodies as compared to trihalomethanes, that do not oxidize and accumulate in the environment;
  • Byproducts (chlorates and chlorites) are not dangerous for the environment, as chlorites quickly reduce to chlorides and chlorates and stable in aqueous environment

In some cases, disinfection is possible with the use of hypochlorite (sodium and calcium hypochlorite). However, the use of hypochlorite for the disinfection of drinking and wastewater is limited by its high cost and low stability.

Mechanical Treatment of Wastewater to Remove Petroleum

Mechanical Treatment of Wastewater

Mechanical Treatment of Wastewater. Among the worst environmental problems is a widespread petroleum pollution of water bodies, coastal areas and soil, due to its increased production, transportation and refining.

Statistics estimate 2% of oil losses during transportation. The losses cannot be avoided during storage of fuels and lubricants on tank farms and oil processing enterprises, which, in accordance with the existing requirements should not be more than 3%. Although in practice this number is significantly higher. This is not surprising, since virtually any oil refining enterprise forms a zone of soil and groundwater contamination.

This leads to disruption of the natural biochemical processes and mass destruction of flora and fauna. Therefore, wastewater contaminated with crude oil is rightly considered to be one of the worst pollutants on the planet.

Mechanical Treatment of Wastewater. Preliminary cleaning of wastewater from petroleum mainly uses mechanical treatment. In general, its efficiency is 65% when cleaning household wastewater and 95% in purification of certain industrial effluents. Mechanical cleaning prepares the wastewater for the following stages of physicochemical and biological treatments. This method is considered to be the cheapest, so it is used very often.

Mechanical treatment of wastewater is necessary to remove insoluble suspended solids through clarification, filtration and sedimentation. The main drawback of this approach is the low efficiency of mechanical equipment. The complexity of petroleum removal is in its spreading in a thin layer on the surface of water. As it is collected, water is captured as well.

Methods for Wastewater Treatment

Methods for Wastewater Treatment

Methods for Wastewater Treatment. The industrial enterprises cause environmental pollution with exhaust gases, wastewater and solid industrial waste.

The bulk of waste of the I-IV class is the combustion residue, animal and plant waste as well as industrial wastewater resulting from wastewater treatment. The large amounts of such waste are due to the outdated technologies that make it impossible to efficiently and quickly purify water. Also there is a lack of treatment facilities.

Continuous development of the society and urbanization lead to an increase in industrial production and, consequently, to an increase of wastewater amounts. The hydrosphere pollution increases, which adversely affects the health of people and the development of fauna and flora. Therefore, an important problem today is the treatment of wastewater, because industrial wastewater contains a variety of contaminants. Especially dangerous is the waste water contaminated with chromium, because this chemical element belongs to the I hazard class.

Methods for Wastewater Treatment. Wastewater treatment uses the following methods: reagent, ion exchange, electrochemical and biological. The most common for chromium wastewater treatment is the reagent method which uses expensive reagents like sodium sulfite, hydrazine, salts of iron (II) and others, the degree of purification is 65-80%. Another effective approach is ion exchange, but it is not widely used because of its duration and cost.

There is also wastewater treatment from chromium by electrochemical method that uses steel electrodes. The drawback of this method is more than four time increase of solid sludge. The biochemical method for purifying wastewater from chromium uses special microorganisms, which consume chromate-bound oxygen; they survive and grow in oxygenated environment. These microorganisms reduce chromate and dichromate ions to chromium hydroxide.

The purification of wastewater by filtration is carried out at the beginning of the treatment, or at the end of the treatment in order to achieve the required physical and chemical characteristics of wastewater.

Wastewater Treatment Unit to Remove Hexavalent Chromium and Other Heavy Metals

Wastewater Treatment Unit

Wastewater Treatment Unit. The process line for wastewater treatment from chromium, lead, nickel, iron and other heavy metals can be equipped with the AVS-100 (150) electromagnetic nano-mill by GlobeCore. It significantly reduces reagent consumption, provides better cleaning and make the process continuous.

The main feature of the electromagnetic nano-mill is the intensive mixing of materials with the help of ferromagnetic particles affected by an electromagnetic field. The impacts and friction of the particles against each other, the walls of the chamber and the material forms colloidal metal, which is an excellent reducing agent. Simultaneously, the electrolysis of water forms hydrogen. Both of these factors affect hexavalent chromium and other heavy metals in the wastewater.

Figure 1 compares the rate of hexavalent chromium reduction in the electromagnetic nano-mill  compared with a conventional stirrer.

Fig. 1. Wastewater Treatment Unit. The rate of hexavalent chromium reduction: 1, 2, 3 – in a stirrer with consumption of the reducing agent FeSO4 of 50%, 80% and 100% of the stoichiometric amount; 4, 5 – in the AVS with consumption of reducing agent FeSO4 of 10% and 30% of the stoichiometric amount.

Analyzing the data makes it clear that the electromagnetic nano-mill achieves a full recovery of hexavalent chromium with 10% of ferrous sulphate. The process takes almost no time and lasts a fraction of a second.

Figure 2 shows a complete process line with the AVS for wastewater treatment.

Fig. 2. Wastewater Treatment Unit. Flow chart for wastewater treatment from chromium on the AVS: 1 –mixing tank, 2 – pump, 3 – reducing agent tank 4 – alkali dispenser, 5 – acid dispenser, 6 – electromagnetic nano-mill (AVS).

The principle of operation is as follows. Wastewater with hexavalent chromium goes into the mixing tank, where acid concentration is equalized and more acid is added. After that the wastewater goes into the AVS,  simultaneously  mixed with ferrous sulphate or sodium bisulfate. The flow meter adjusts the flow rate.

After chromium recovery the waste water flows into the second AVS with lime milk, forming chromium hydroxide and other heavy metal salts. The acidity level is controlled by a pH meter, which is placed over the device.

If the residual concentration of hexavalent chromium exceeds the desired value, it is necessary to adjust reducing agent consumption.

Industrial Wastewater Treatment Using an Alternating Electromagnetic Field

industrial wastewater treatment

Industrial Wastewater Treatment. Environmental pollution is a global problem requiring effective and integrated solutions. An important part of protecting the environment is keeping the water resources pure and clean, when they are contaminated with heavy metals, acids, alkalis and other industrial wastes.

The existing wastewater treatment technologies are not always reliable and efficient, requiring the development of new technologies and new generation devices that can overcome these limitations. GlobeCore offers new equipment: its electromagnetic nano-mill AVS 100 (150). This equipment operates using the energy of rotating electromagnetic fields of high intensity. The AVS operating space is a chamber with ferromagnetic particles inside. The rotating electromagnetic field turns the particles into dipoles. The particles begin to move in complex trajectories colliding with each other, with the walls of the chamber and with the material.

The AVS chamber performs the following processes:

  • Decontamination of water;
  • Recovery of various compounds;
  • Partial decomposition of water;
  • Oxidation;
  • Deposition of metals from the solution as hydroxides;
  • Partial decomposition of organic compounds with complex and polyatomic structure.

Rapid movement of the needles (ferromagnetic particles) and the resulting cavitation in the liquid can significantly speed up the flow of physical and chemical reactions (hundreds and even thousands of times) improving industrial wastewater treatment.

Practical studies show that the AVS dissolves components in water faster than a stirrer with heating. It uses less energy and saves production space (with smaller size of the equipment).

Wastewater treatment with the AVS includes pre-filtering, cleaning and decontamination, controlling chemical composition of clarified water and sludge disposal.

Among the other advantages of the AVS units in wastewater treatment are:

  • Ability to operate with virtually any wastewater composition;
  • Easy integration into existing production lines;
  • Management and control of the device by changing the process parameters.

Depending on the degree of purification achieved, the purified water can be directed to urban wastewater treatment plants, or to the open waterways.

Wastewater Treatment Based on Electromagnetic Nano-mill

wastewater treatment

Environmental problems are vitally important and require complex approaches. The most urgent task is improving the water resources of the planet which are polluted by industrial and agricultural waste. This problem is solved by wastewater treatment systems.

Currently wastewater treatment mainly uses ion exchange, reagent and electrochemical methods, which are designed to deal with such harmful substances as chromium, cadmium, nickel, copper, etc. But despite the progress, the question of economical and efficient wastewater treatment still stands.

The reagent and ion exchange methods are laborious and time consuming. They require large amounts of reactants and involve significant operational costs. The equipment used in these technologies is large and bulky. The duration of the treatment may vary from 15 to 40 minutes with 150-250% of reagents use.

The duration of ion exchange is 0.5-1.5 hours. The ion exchangers require a regular recharge by washing in a solution with high concentration of sodium ions that needs further neutralization.

The main disadvantage of electrochemical method is the high power consumption and applicability testing required in each particular case.

The electromagnetic nano-mill as a part of wastewater treatment system

Wastewater treatment system with integrated electromagnetic nano-mill (AVS) eliminates the above disadvantages. AVS is a device operating on the principle of a vortex layer generated by ferromagnetic particles of certain diameter and length. The rotation of the particles is facilitated by electromagnetic fields. The device intensifies and improves the quality of wastewater treatment, which is achieved by a number of effects that occur in its chamber, such as vigorous stirring and dispersing, electrolysis, and high local pressures. Wastewater is treated to remove chromium in a single stage in an alkaline environment, instead of the two-stage process in acidic conditions. This significantly simplifies the process and reduces the consumption of reagent. The wastewater is treated in the AVS in a few seconds instead of the 15-30 minutes in conventional equipment.

Table 1 shows the results of wastewater treatment using AVS.

Table 1

The results of wastewater treatment in industrial environment using an electromagnetic nano-mill

Initial concentration of metals in wastewater, mg / dm3

pH of the process

FeSO4, percent yield  % of the stoichiometric

Alkali reagent percent yield  ,% of the stoichiometric

Processing Time, seconds

Residual metal content, mg / dm33

Сr6+-50

(Fe, Cu, Zn, Ni, Cd)-300

7,5-8,0

90

100

0,5-2,0

(Сr6+, Fe, Cu, Ni) – 0,00.

Zn-0,008 Cd-0,007

Сr6+-100

(Fe, Cu, Zn, Ni, Cd)-370

7,5

85

90

0,5-2,0

Сr6+-0,20

Fe- 0,00

Cu – 0,12

Ni-0,06

Zn-0,13

In conclusion, it is easy to see that using the AVS in wastewater treatment:

  • Reduces reagent consumption by 1.5-2 times;
  • Reduces energy consumption (0.3 kW × h to 1 m3 instead of 0.6-0.8 kW × h (mechanical stirrer) and 2-6 kW × h (electrocoagulation method);
  • Treated wastewater is reused in production;
  • Performs reliably and efficiently.

Improving the Cracking Resistance of Concrete Using Electromagnetic Nano-mill

concrete

For more than 100 years, scientists around the world explored the cracking resistance of concrete. The central scientific problem of this research is to establish the patterns of crack development and their effect on the bearing capacity of the element. There are two types of cracks typical for reinforced concrete structures:

The first type of cracks is associated with plastic properties of concrete.

These cracks appear during the hardening process and during long-term processes (such as creeping) of concrete or with changes of ambient temperature;

The second type of cracks, which inevitably occur during use of reinforced concrete elements under the influence of permanent and temporary loads. Today it is generally accepted that crack formation and further shear fracturing of the protective layer are the main factors that determine the durability, reliability and load-bearing capacity of concrete elements.

With time the cracks cause a sort of “domino effect”: corrosion in the crack zone of reinforcement becomes more intense, such phenomena generate pressure on the protective layer, it breaks down, the crack widens, the corrosion increases, and it is an endless circle. Moreover, the intensity of the degradation process increases nonlinearly.

It has been established that the use of nano-additives and magnetization of water can increase concrete cracking resistance. The use of AVS-100 (150) electromagnetic nano-mill by GlobeCore allows to simultaneously magnetize mixing of water and concrete and stir the raw concrete components more thoroughly.

Increasing the cracking resistance can be achieved by selecting the optimum length of time for magnetizing the water and the percentage of nano-additives. Therefore, the main problem in this case is to find the correlation that ensures maximum strength. The table below shows the increase of concrete strength with nano-developed additives and magnetizing water for five seconds.

resistance of concrete

Fig. 1. Resistance of Concrete. The strength of concrete on magnetized water (to = 5 c) with nanofiber additives

The graph above clearly shows the increase in strength. It is achieved by the electromagnetic nano-mill, which improves the quality of the concrete mixture.

Research on Coal Regrinding for CWSF Production

Coal Regrinding

Coal Regrinding. Natural energy resource reserves are distributed unevenly and many countries experience an acute shortage of such raw materials. Hence it is necessary first to seek cheaper options for energy imports, then to take measures to ensure their economic use, and also to look for alternative sources of heat and power.

Some experts point out that the so-called coal-water slurry fuel (CWSF) is particularly promising as one of alternative fuels. CWSF is a dispersed system consisting of water, fine carbon and a chemical additive. It was not until the 1970’s that due to the outbreak of the “oil crisis” the replacement of traditional energy resources with CWSF was extensively discussed. That was largely attributed to the efforts of Chinese, Japanese, American and Swedish scientists. Japan and China have not abandoned this idea and continue working on this subject at present.

The main points that allow CWSF to be considered as a real alternative to traditional energy sources are:

  • Low combustion temperature (a 70%-reduction in nitrogen oxide emissions);
  • Explosion and fire safety;
  • Availability of all the technological properties that are peculiar to liquid fuels;
  • Stability of properties during long-term storage and shipment;
  • Switching heat and power equipment to CWSF does not require significant design changes;
  • Reduced cost of one ton of fuel equivalent ;
  • Reduced cost of energy output.

Taking into consideration that CWSF contains 60-70% of micronized coal with the size of 45 … 250 microns, it is necessary to apply special mills during its production. Traditional CWSF production technology involves the use of ball and rod wet-grinding mills. The average energy consumption rate in this process ranges from 86 to 248 kWh/t.

Such a high energy consumption rate is the result of a low energy coefficient of grinding machines that appear to be rather bulky.

In order to eliminate these drawbacks, the GlobeCore R&D department researched coal regrinding with magentic mills for subsequent CWSF production. You can find a detailed description of the experimental procedure and findings, featured in the two brief video reports below. As one of the main findings, note the production of CWSF with much lower energy consumption compared to existing technologies.

GlobeCore manufactures both stock and custom designed magentic mills. This equipment can be used for:

  • fuel preparation for pulverized combustion;
  • coal-water fuel production;
  • coal and biomass co-combustion.

GlobeCore’s magentic mills can serve as the basis for designing and implementing both completely new systems and upgrading existing ones.

Improving the efficiency of industrial wastewater treatment in the electromagnetic nano-mill

The environmental protection measures include saving the planet’s water resources and management of used resources which occupy large areas. Especially important is the treatment or industrial wastewater, among which the wastewater of chemical, engineering, food, instrument, petrochemical and other industries poses the greatest danger to the environment.

Wastewater of these industries varies in amounts, composition and concentration of contaminants and thus requires the application of reliable and efficient cleaning methods and appropriate equipment. The problem of wastewater purification is caused by the complexity of physical and chemical processes involved.

Existing methods of industrial wastewater treatment. Their advantages and disadvantages

The methods of industrial wastewater treatment applied today are ion exchange, reagent and electrocoagulation. They treat wastewater, removing chromium and other heavy metals. In spite of the existing achievements, they are not fully efficient and economical and do not provide rational management of water resources. These methods also produce large quantities of waste requiring disposal. In most cases, the resulting sediment is dried and stored on the premises or in places specially designed for waste disposal at extra cost. In recent years, much attention is paid to no-waste or low-waste technologies. But, as practice shows, they require large investments.

The main drawbacks of ion exchange and reagent methods of wastewater treatment with traditional equipment are the process duration and the large consumption of reagents, significant operating costs, high metal consumption and bulky equipment with large footprint.

Electrocoagulation process leads to a higher content of iron and aluminum in the treated water and a high electric bill. It is significantly affected by the flow fluctuations, temperature, salt content and concentration of pollutants. This method requires a feasibility test in each particular case. In addition, the electrocoagulation process often does not ensure the necessary water quality to return to the production facilities and its subsequent use in manufacturing processes

What is an electromagnetic nano-mill (AVS)?

The first electromagnetic mill (AVS) was constructed in the 1960’s. The principle of this device is very simple. It is a hollow cylinder made of nonmagnetic material. Inside this cylinder are ferromagnetic particles (the so-called “needles” with magnetic properties, with a ratio of length to diameter of at least 20).

Outside the cylinder is wound with inductor coils that create a rotating magnetic field. When voltage is applied to the coil, the magnetic particles come into a complex oscillatory motion, forming electromagnetic field in the operating space. Each particle moves in the direction of the rotating field at high velocity, colliding with each other.

The interaction of the rotating electromagnetic field produced by the inductor and the ferromagnetic needles create a number of effects, which together with mechanical and thermal effects change the physicochemical properties of the substance. The effects in the operating chamber of the AVS are highly energetic.

Today, the AVS are successfully used in many process lines, improving productivity by tens and thousands of times.

Possibility of AVS application to improve industrial wastewater treatment

The analysis of the intensifying factors which take place in the AVS shows the processes that influence industrial wastewater treatment:

  • Intensive dispersion and mixing of the components;
  • High local pressure;
  • Electrolysis;
  • Acoustic effects;
  • Electromagnetic effects, etc.

Kinetic intensification of the processes instead of diffusion completely overcomes the disadvantages of the existing methods of wastewater treatment.

Until recently, the performance of one unit was relatively low to provide, for example, a large company or a city with wastewater treatment. However, the company has created units with 100-1000 m3/h capacity. Therefore, there are no performance issues today.

Research results

We tested the AVS (based on the AVS-100 commercial sample) for purification of chromium-containing acid-alkali wastewater with different compositions of chromium, iron, nickel, zinc, copper, cadmium and other contaminants.

The results of the tests were as follows. The AVS achieved a high degree of decontamination (below allowable limits) of chromium and heavy metals (Fe, Ni, Zn, Cu, Cd). Reagent consumption was 90-100% and the operation of treatment plants was greatly simplified. The conventional methods use 115-120% Ca (OH) 2, Na2CO3 and 150-175% of the reduction agent (FeSO4).

Using the AVS system  for simultaneous cleaning of chromium and acid-alkaline wastewater ensures water quality standards marginally below allowable concentrationы, reduce reagent consumption by 1.5-2 times, half the power consumption, and reduce water treatment plant footprint by 10-15%.

AVS can be retrofitted into the existing line easily and cheaply and can be efficiently used in any industrial wastewater treatment plants.

Ion Exchange in Electroplating Wastewater Treatment

The process of ion exchange has found practical use in wastewater treatment and water preparation systems, specifically for demineralization, desalination, correction of the chemical composition of water, removal of toxic or valuable substances in processing natural or industrial wastewater.

Despite the abundance of the chemical properties of electroplating wastewater contaminants, both organic and inorganic, the specific chemical interaction of ions, which exchange ionites (forming complex functional groups, weakly ionized form of ionites) becomes important.

Ion exchange is the most environmentally dangerous technology for deep purification of water and using it as a part of combined water treatment systems requires research of the interconnected processes: the exchange of ions between phases and the transfer of solvent.

The end result of the balanced distribution in these system is the result of the Donnan distribution of components and the chemical reactions of ion exchange.

This can be explained by the structural changes in the system of ionite-solution, since we know that wastewater treatment begins with the cationic exchange of cation exchanger with a sulfate group. The sulfate group in this is an ionogenic group and has the highest affinity with multicharged ions, which are the primary contaminant in electroplating wastewater. This is due to the following processes:

  • strong electrostatic interaction of multicharged counter-ions with fixed ions;
  • strengthening of hydrogen bonds between the molecules of hydrate water;
  • strengthening of bonds with counter-ions and fixed ions.

Complete regeneration of cationite requires a 2.5 excess of acid, while desorption of double-charged ion from the cationite, even larger acid exceed is required. The result is that a significant excess of acid exists in wastewater after cationic exchange filters, along with the salts of copper, nickel, calcium etc. This limits the use of eluate (regeneration solutions) for their recycling.

The process of anionic exchange is performed consecutively first in low-basic and then in highly basic anion exchangers. The need to used low-basic anion exchangers is due to their easy regeneration, but the low-basic anion exchangers absorb practically no weak acids. It is important that highly basic anion exchangers function in any pH range. At the same time, highly basic anion exchangers are more difficult to regenerate.

At present, the degree of wastewater mineralization and reduction of its volume occurs. Therefore it is reasonable to consider combined batch or semi-batch systems with complete purification and final polishing to reuse the water in the production process.

Using Biosorbents to Remove Oil From Water

Remove Oil From Water. Dumping of insufficiently treated household and industrial wastewater contaminates water, poisons water bodies and destroys ecosystems. Among the substances contaminating oceans, seas, lakes and rivers of the planet, various oil products hold a leading position.

The amount of oil products dumped into the ocean, but different accounts, varies from 5 to 10 million tons annually. The main sources of such contamination are crude oil extraction sites, oil transportation, terminals and storage facilities, railroads etc. The most toxic oil products are naphthalene, methylnaphthalene, phenanthrene and trimethylbenzene. Besides, there is direct economic damage from oil products getting into the water, in the order of several billion dollars each year.

That is why the search for new methods, materials and technologies to purify water and minimize the amount of oil and oil products in the hydrosphere.

There are mechanical, chemical and biological methods of removing oil from wastewater. Adsorption is widely used for deep purification of contaminated water. In this respect, the above methods have several disadvantages.

Chemical methods involve mixing of chemical reagents with the water. The reactions occurring in the treatment process may result in formation of materials more toxic than before.

Mechanical methods remove only the oil and oil slime from the surface. Emulsified and solved oil cannot be removed, making this method inefficient.

Biological oxidation can be efficient in case of low oil concentration, in the surface layers of water in a certain pH and temperature range.

Adsorption is one of the most promising directions in water treatment. The advantage of the method is its low cost, general availability, enough raw materials, non-toxicity, high efficiency and the capability to treat wastewater with many contaminants.

Adsorbents can be inorganic, synthetic, natural organic and organomineral. All are similar in their adsorption and other characteristics. They are used as Natural materials of vegetable or mineral origin are used(cotton, peat, peat moss, sawdust, wood chips, wood powder, hemp, hay, clay, perlite etc), as well as artificial synthetic materials based on rayon, hydrocellulose, synthetic fibers, thermoplastic materials, foam polyurethane etc.

The analysis of sorption methods to remove oil and its products from water indicates the prospect of using natural adsorbents. These are peat (absorbs 3.5 to 9.8 kg of crude oil), wool (8-10 kg of oil absorbed by one kilogram), sawdust, moss, seed peels, activated charcoal, etc. Sapropel and lignin are also quite promising as adsorbents.

Purification of Household Wastewater

Household wastewater goes into sewage from kitchens, bathrooms etc. Such wastewater can be treated using mechanical and biological methods.

Purification of wastewater is a complex multistage process, which begins in the input chamber. Then the water is filtered mechanically to remove garbage etc. The liquid phase is separated from the solid phase, by using settling tanks, grates, sand traps etc. Mechanical influence is only a preliminary stage before biological purification.

Microbial metabolism removes organic contaminants from the wastewater. The biological treatment facilities are of two types:

  • with conditions close to natural (natural biological treatment);
  • with artificial conditions (artificial  biological treatment).

Natural bio treatment can be performed in sewage farms, oxidation ponds etc, while artificial measures include aero and biofilters, as well as aerotanks. In the latter case, all purification processes are mode intensive, due to better conditions for microbial life.

A biological filter is a special structure where wastewater is filtered by passing through material covered with a biological film. This film is made up of microbial colonies.

Aerotanks are long rectangular concrete vessels with slow motion of mixed wastewater and biological sludge. Air is supplied to the tank so that the microbes can function, which does not only supply oxygen, but also maintains the activity of the sludge.

After dehydration, the sediment from wastewater may be used in agriculture as organic fertilizer, but only if it contains no toxic waste, such as heavy metals.

Chemical Purification of Wastewater

Chemical Purification of Wastewater. Water going into the sewage system must be processed to remove heavy metals and other hazardous contaminants. This purification requires a complex of measures.

Wastewater can be classified by origin:

  • industrial;
  • household;
  • precipitation (snow, ice etc).

Chemical purification of wastewater implies the use of special reagents which react the contaminants. Such reagents are chlorine, potassium permanganate, chlorine and sulfur acid, sodium hydroxide, ozone, lime etc.

Chemical purification often precedes biological purification. Let us look at chemical wastewater purification in mode detail.

Neutralization of wastewater implies bringing pH of the wastewater to 6.5-8.5. In practice this may be achieved by mixing acidic and basic wastewater, chemical introduction and filtration. Acidic water can absorb ammonia, basic wastewater can dissolve gases.

Oxidation is used for decontamination when removal of contaminants is not required. Some of the oxidants used are chlorine dioxide, calcium chloride, air oxygen, ozone and other substances.

The oxidation process make the wastewater less contaminated and allows to remove toxic substances. The most efficient oxidant is fluorude. However, this substance is rather aggressive, making it hard to use in large quantities. So in many cases chlorine is prefered as a means to remove hydrogen sulfide, cyanides, methyl-sulfuric compounds etc.

Electrolysis is the oxidation of wastewater by electrochemical methods. The latter are efficient in purification of wastewater, removing organic and inorganic substances.

Even when using well-known and proven methods, several problems remain: long duration of the process, large footprint required, high chemical consumption. Hence the need to improve process efficiency.

GlobeCore offers a solution: installation of magnetic nano-mills into the water treatment systems.

The ferromagnetic particles located in the chamber of the AVS unit, intensively stir and mix the reagents in the chamber. Under the influence of the shocks and friction, the materials are broken down into colloidal particle sizes. The colloidal metal is good reduction agent. At the same time, electrolysis causes formation of hydrogen in the vortex layer. Both factors have significant influence on reduction of hexavalent chrome and other metals in wastewater. This ability of the vortex layer allows to reduce iron sulfide consumption, or even achieve complete reduction of hexavalent chrome due to colloid metal and hydrogen only. The process in the AVS occurs in fractions of second, making the process continuous. Intensive mixing of reagents and the influence of the EM field, as well as the dispersion of the product compounds causes the formed metal hydroxides to be more dispersed than materials obtained in mechanical agitators. Interestingly, increased dispersion of the sediment does not slow the process of settling. On the contrary, sedimentation of the solid particles after the AVS process occurs up to two times faster than in a mechanical agitator. This is due to the intensive magnetic influence on the suspension, which changes the interfacial tension on phase boundary.

An important feature of the vortex layer is the fact that after the processing, the chemical and physical properties change, which in turn changes the chemical activity of the resulting product.

Using a unit with mechanical agitators requires a lot of space and investment. The duration of a purification cycle in this method can be 30 to 120 minutes. A system based on the AVS magnetic nano-mill to decontaminate wastewater by reducing chrome with chemical reduction agent in basic media and precipitation of the contaminants as metal hydroxides only includes vessels for iron sulfide and lime milk with portioning devices, the AVS mill and a filter or solid waste settling tank.

Treatment of Electroplating Chromic Wastewater

While the industrially developed regions of the country suffer from lack of clean water, electroplating consumes enormous amounts of water: more than 50 million cubic meter per year. This industry is one of the most hazardous, with harmful work conditions, large amounts of wastewater contaminated with highly toxic chemicals. The main components of electroplating wastewater are inorganic substances, such as heavy metals: chrome, zinc, nickel, copper, cadmium etc. Hexavalent chrome compounds are especially hazardous.

To toxicity of Сr6+ is in the suppression of growth, retardation of metabolic processes in the form of genetic, gonadotropic, embryotropic changes, while chrome compounds are highly carcinogenic. One of the priorities is implementation of modern decontamination processes to obtain waste with the concentration of contaminants which does not exceed regulatory limits.

When selecting the method of decontamination, it is necessary to consider the methods of handling solid waste. This is due to the fact the solid waste extracted from wastewater poses a great danger to groundwater if stockpiled in landfills.

Among the many existing methods of chromic wastewater decontamination, such as chemical, ion-exchange, adsorption, membrane, biochemical and electrochemical, the chemical method is used the most. The reduction agent of hexavalent chrome can be iron sulfide, calcium sulfide, hydrogen peroxide, formaldehyde, powder aluminum, hydrazine, barium salts, lead compounds, metal scrap etc. For reduction of one part of Cr6+ up to 16 parts of reduction agent are required. In the end, the process results in large amounts of solid waste(10.0 – 12.5 thousand tons per year), which contain large amounts of hydroxides, carbonates and heavy metal salts.

The membrane methods of wastewater decontamination are the reverse osmosis and ultra-filtration. Membrane methods offer high degree of purification, allow to return the water back into the production and regeneration of the solved substances, all with rather low energy costs. However, ultra-filtration units accumulate the captured substances on the surface of membranes, reducing permeability and selectiveness. Low chemical resistance in aggressive media and high cost allow membrane application only where the media is not aggressive and the concentration of metal ions exceeds the limits by a small amount. Due to the above, membrane technology has not come into wide use for local decontamination of electroplating wastewater.

The sorption methods of electroplating are adsorption and ion-exchange. Natural and porous materials are used in this process. Industrial application of this process is limited due to the complicated regeneration and reuse of the sorbent.

Ion exchange method is widely used. Chrome is extracted and reduced by two columns, filled with highly acidic cationite and highly basic anionite.

Another possible method is electrochemical coagulation with soluble steel anodes. In this method, bichromate and chromate ions are reduced by iron ions Fe (II), which form during electrolytic dissociation and due to cathode reactions.

Oil Processing Wastewater Treatment Facility

Wastewater Treatment Facility. Environmental protection and reasonable use of natural resources, ecological security of the society are the main conditions of sustainable economic and social development.

Industrial production generates waste in solid, liquid, gaseous and mixed forms, influencing the environment, in the course of processing various natural resources.

The environment is degrading rapidly due to::

  • land being reserved for mining waste;
  • disruption of natural hydrological conditions in ground and surface waters;
  • water abstraction of large territories or flooding of large areas;
  • salination of soil;
  • reduction of drinkable, ground and drain water;
  • dust and gas in the air and harmful substances which come into contact with the human sphere (water, soil, air), such as compounds of heavy metals, sulfur, nitrogen, hydrocarbons etc.

The industry uses various treatment methods, which involves equipment insufficient for high degree of water purification due to constantly changing contaminant composition or inefficiency of the equipment.

Oil processing facilities generate waste water which contains crude oil and its derivatives, particulate matter, salts, demulsifiers and other contaminants, which are removed by mechanical, physical, chemical and biological treatment. However, the degree of purification does not satisfy regulatory requirements, since many facilities use obsolete treatment equipment.

Gravity purification of wastewater in open settling tanks is used in crude oil extraction. The degree of purification is low, besides, the open settling vessels take up much land and contaminate the environment. Open ground settling vessels are inefficient, so new thin-wall settling tanks, which are more efficient, have been developed. The main factors of their efficiency are the following design elements: the length and height of inclined surfaces, square area, location of the outlet. It should be noted that operation of filters with low grain loads is not automated and requires labor and time for regeneration.

All of this compels the search for methods to increase the efficiency of wastewater purification, among which is the magnetic nano-mill (AVS). It is a chamber (tube) located inside an inducer of a rotating electromagnetic field. Ferromagnetic elements are placed inside the tube.

An analysis of the intensification factors in these devices (intensive mixing and dispersion of components, acoustic and electromagnetic effects, high local pressures and electrolysis) shows that some of these factors can influence the process of wastewater treatment:

  • geometry and mode of the vortex layer, its hydrodynamic properties which ensure intensive mixing of the processed materials;
  • electrochemical factors, electromagnetic treatment and activation of substances in the vortex;
  • phase dispersion.

Methods of Dry Construction Mix Modification

Dry Construction Mix Modification

The high quality of the modern construction mixes is impossible without using special modifying additives. They allow to adjust the properties of the material, making solutions with the required qualities for use in any (even extreme) conditions.

A relatively large amount of such additives is available in the market today. These are mostly surfactants, electrolytes, polymers etc. The history of modifying construction materials begins in the ancient times. Some of the oldest surviving buildings on the planet were built with lime concrete and mortar with vegetable oil, egg whites, dairy, boiled tree bark etc.

Binding materials have replaced the ancient modifiers with time. But, in the beginning of the previous century, modifying additives returned into construction on a new technological level. Many countries have already completely transitioned to modified concrete and mortar (with the market share reaching 90-95%).

The form in which the additives are used depends on the technology of their application. For concrete or otherwise soluble mixes, additives are introduced with water, while in preparation of dry material, they come in the form of powders, which must:

  1. spread evenly through the mix;
  2. have low water absorption ability.

The most widely accepted classification of modifying additives for dry construction mixes is as follows:

  • rheological properties adjustment;
  • structure adjustment;
  • settling and hardening process adjustment;
  • special modifiers;
  • multifunctional modifiers.

The modifiers which change the rheological properties of materials are the most widely used. This is because they can be used for any construction material mix.

Settling and hardening modifying additives are mostly used for modification of dry construction mixes based on gypsum binding, repair mixes, mixes for machine application, flooring materials etc.

Structure regulators are used to improve the qualities of plaster, repair and waterproofing materials.

Special modifiers are required if construction materials are used in special conditions with special requirements.

Each of the additives is supposed to change a certain quality (or several) and must not influence other important properties of construction material mixes and solutions. That is why multifunctional additives were developed: these allow to reduce or completely remove the negative influence of certain components, while retaining their positive effects. Multifunctional additives are used for flooring materials, plasters and special construction material mixes.

Mechanical Activation of Dry Construction Material Mixes Using Magnetic Nano-mills

Research shows that approximately 20% of the cement in concrete does not take part in hydration. These are mostly particles 70 micron and larger.

Magnetic nano-mills facilitate additional pulverization and activation of cement with mean surface area of 4500 – 5000 cm2/g.

The principle of operation of such mill is rather simple. They consist of a hollow cylinder made of non-magnetic material. Inside are ferromagnetic particles in the shape of a needle. Outside of the cylinder is an inducer which generates a rotating magnetic field. When the inducer is powered, the particles move along complex trajectories, forming the so called vortex layer. If large particles of cement are placed inside the cylinder, they will be turned into finely pulverized powder within seconds. Mechanical activation of cement reduces the amount of material used and improves concrete quality.

It should be noted that vortex layer mills can also be used to activate old compacted cement. Construction specialists know that if the сement is not used immediately and stays in storage for a month, activity of the material is reduced by at least 15%. When processed in the vortex layer, the compacted grains are broken and the cement is activated, oxides are removed and the cement is made as good as new.

Modern Methods of Wastewater Treatment

When selecting methods and processes for treatment of industrial wastewater, several factors must be considered, such as the amount and nature of waste, concentration and type of contaminants, requirements treatment results as well as the possibility of using this water in water supply systems.

In recent years, chemical, ion-exchange and electrochemical methods have come into wide use. Chemical reagent methods are mostly used for treatment of water contaminated with chrome and other heavy metals.

The idea of these methods is the use of special agents to reduce hexavalent chrome to trivalent and precipitate it. Some of the reagents are ferrous sulfate, steel scrap, sodium bisulfite etc.

Evaluating the perspectives of chemical treatment, the following disadvantages become apparent:

  • low degree of heavy metal removal;
  • high content of salts, which does not allow to use the water in return cycle;
  • irrecoverable loss of metals;
  • high consumption of reagents;
  • large equipment footprint.

Ion-exchange method is a promising approach in industrial wastewater treatment. It facilitates almost complete removal of contaminants from wastewater and allows to reuse the water. However, this method has certain limitations in removal of heavy metal salts.

This approach dominates in design of closed loop water supply systems, and allows to reduce consumption of fresh water in industrial processes. However, one of the effects of this method is the large footprint of treatment facilities.

Among the disadvantages of ion exchange are:

  • high reagent consumption for ionite regeneration;
  • large amount of salts entering water bodies along with neutralized regeneration products;
  • high water consumption on ionite processing and washing.

Electrochemical treatment has come into wider use recently. It allows to remove chrome and heavy metals from wastewater by steel electrodes. The idea is to reduce chrome by bivalent iron ions, which form from electrode dissolution. In general, the specifics of electrochemical method make it quite complex.

Wastewater treatment technology

Development of wasteless technology is an important measure to protect the environment from anthropogenic loads by separating contaminants from water, and possibly to recycle the contaminants for use in technology processes.

This can be achieved by using modern efficient technologies. However, wastewater has several types of contaminants and so using only technology process in real conditions might be economically problematic or too cumbersome.

Wastewater is most often processed using traditional treatment methods. However, if wastewater contains several organic substances, similar in physical and chemical properties, the technology process becomes complicated.

The amount of wastewater, including that containing hazardous organic materials, grows every year. To prevent further increase of wastewater amount in the industry, a promising approach is to develop wasteless technology processes and implementation of closed loop water supply systems. That is why comprehensive purification processes are being developed. Also, new methods of chemical removal, such as iron, fluoride, manganese, pesticides and other chemicals, petroleum products etc.

Hexane is used in many industries. For instance, hexane solvent is widely used in vegetable oil extraction. Such solvents as benzol, toluene, ethyl acetate, isopropanol and cyclopentane.

Reduction of organic substances in wastewater can be achieved by local purification. The processes involved adsorption, reverse osmosis, ultra-fitration, electrodialysis and ion exchange. Oxidation by atmospheric oxygen and ozone allows to remove up to 99% and 75% mercaptans. Resinous materials are removed by filtration through activated charcoal or coke.

Activated charcoal can easily adsorb acrylonitrile, aniline, benzene, chlorobenzene, cyclohexane, cresol, mercaptan, naphthalene and phenol. These substances can be extracted from activated charcoal by chloroform, ethanol, acetone, while reverse osmosis removes up to 90% of organic substances from wastewater.

In sulfate cellulose factories, the local purification methods include purification of wastewater with chlorine, lime, ozone and oxygen, which oxidize hydrogen sulfide and hydrosulfide. To oxidize organic substances in wastewater and for disinfection, chlorine is used, to remove odor, apart from ozone and chlorine, hypochlorite and manganese dioxide are used; unpleasant smell of sediment is neutralized at 730ºС.

As a rule, organic substances in wastewater are biologically oxidized in local or factory facilities. However, many are resistant to biological oxidation, and in such cases, thermal decontamination (incineration) is often used. Organic wastewater materials are incinerated at 800-1000ºС. Incineration is often used for such substances as benzol, toluene, resins, aldehydes and paraffins.

Using natural sorbents is treatment does not require their regeneration, while contaminated sorbents may be used in other chemical, construction or agricultural processes. Therefore adsorption is a promising and relatively inexpensive method of wastewater purification.

Chromatographic processes, especially adsorption, are often used in chemical and pharmaceutical industries, in biotechnology for breaking chemical and physical bonds. Many types of adsorbents with various structure and chemistry found use in adsorptive chromatography.

Intensification of Wastewater Treatment in Food Production

Intensification of Wastewater Treatment. Treatment of wastewater, including that in food production industry, is a serious problem. Today, industrial processing of agricultural materials without consideration of environmental concerns causes contamination not only of the atmosphere and water bodies, but also the soil, ruining its fertility. Sugar, alcohol, yeast and meat processing facilities are often surrounded by ‘dead zones’, contaminated due to inefficient treatment of waste.

Chemical and biological methods of wastewater treatment are used in food production industry.

Intensification of wastewater treatment in many cases can be achieved by coagulating particles under the influence of coagulants, flocculants, adsorbents and mixtures thereof. Coagulants of various origins are used to treat wastewater, including certain salts of iron, aluminum, polymer guanidine compounds etc.

Aluminum sulfate and its primary salts are widely used in purification of wastewater by separating suspensions and pre-treatment of water. The coagulating effect of aluminum salts is high both in acidic and alkaline media. A significant advantage of these coagulants is a sizable reduction of aluminum content after coagulation.

Sulfates and chlorides are the most often iron salts used. Other coagulants are obtained by chlorination of iron filings in water solution and anodic dissolution of iron in solutions of sodium chloride and sulfuric acid.

Biological purification of wastewater is a promising direction since wastewater of the food production industry contain many substances which are easily oxidized by microorganisms: proteins, hydrocarbons and fats. However, most of treatment facilities in food production involve mechanical methods or treatment in filtration fields (by extensive ground methods) which cannot achieve the desired results and lags behind the modern requirements to the process.

Intensification of Wastewater Treatment. A very important and complex problem in both anaerobic and aerobic treatment of wastewater is the presence of solved nitrogen in the water. Insufficient removal of ammonium from wastewater contaminates underground and surface water by toxic ammonium, nitrates and nitrites. These substances stimulate the growth of algae and reduce the amount of solved oxygen in natural water bodies.

The natural circulation of nitrogen is closely connected to the water cycle. The research of nitrogen transformation in the biosphere draws interest lately. The high content of organic and inorganic nitrogen compounds has a negative effect not only on water ecosystems, but on the biosphere as a whole. The presence of nitrogen in the form of ammonium can also cause undesired consequences. Particularly, decomposition of ammonium salts release toxic ammonia. Besides, oxidation of ammonium nitrogen reduces the content of oxygen in the water to 22-44%. The result of reaction of ammonia with active chlorine in decontamination at drinkable water preparation facilities is the formation of chloramines, which are toxic and mutagenic. In general, increase chlorine absorption by water and reduction of decontamination degree has been noticed in the process of preparation of water with increased content of ammonium, which is unacceptable for household supply.

The most complicated part of the problem with nitrogen compounds in wastewater is the removal of ammonium nitrogen. Particular attention is paid to this process.

Removal of nitrogen from wastewater is possible with various technological and biotechnological measures. They mostly involve improvements of process equipment, such as the use of biofilters, rotating contactors etc.

We recommend to take a look at GlobeCore’s wastewater treatment intensification equipment.

Neutralization of Wastewater

Neutralization of wastewater is required before releasing it into water bodies or reuse in various technology processes. Wastewater containing acids or alkali must be neutralized.

Water with pH of 6.5 – 8.5 are considered neutral. Neutralization is required where pH is below 6.5 and above 8.5. Practically, the highest danger is posed by acidic wastewater containing salts of heavy metals.

Neutralization is a chemical reaction between two substances, of which one has the properties of an acid and the other one of a base. The result of the process is that both substances lose these properties.

There are several methods of neutralization:

  • mixing of acidic and basic wastewater;
  • using chemical agents;
  • filtration of acidic wastewater through neutralizing materials;
  • absorption of acidic gases by basic water or absorption of ammonia by acidic water.

The method is selected based on the following factors:

  • volume of waste water;
  • concentration of wastewater;
  • the manner in which wastewater is transported to treatment facilities;
  • availability and the cost of chemicals.

Neutralization of Wastewater. Neutralization by mixing is used when two facilities, each generating separately acidic and basic wastewater are located nearby. It is important that water contains no other contaminants. Mixing can be performed in special tanks, both with or without mechanical agitators. In the latter case the process is driven by the air coming from the supply line at 20-40 meters per second.

The neutralization method is used when the facility only has acidic or basic wastewater and there is no way to set up a reaction between the two. This method is used more often when working with acidic wastewater. While selecting neutralization chemical, consider the specific acid, its concentration and solubility of salts formed in the reaction.

Filtration through neutralizing materials (magnesite, dolomite, lime, marble, chalk etc) is performed in special neutralization filters. Continuous filters are used for neutralization of sulfuric, chlorine and nitric acid if the concentration in water is below 1.5 grams per liter.

Basic wastewater can be neutralized by using gas containing CO2, SO2, NO2 etc. This method allows not only to neutralize wastewater, but also to treat the gases.

Removal of Phosphorus From Wastewater: a Review of Methods

Removal of Phosphorus From Wastewater. Wastewater generated by the industry and agriculture in many cases contains large amounts of ammonium and phosphorus. Insufficient removal of these from wastewater is a source of contamination of ground and surface water and causes eutrophication of water bodies. Biogenic elements cause proliferation of cyanobacteria. Excessive activity of algae degrades operation of water intakes and fishing, reduces the hydraulic parameters of the flow (the speed of flow near the banks); algal bloom reduces the amount of solved oxygen, has a negative impact on flora and fauna and disrupts normal functions of natural ecosystems.

High level of phosphates in wastewater has been a problem in the last decade, when the content of phosphate has grown from 6-8 mg/liter to 20-25 mg/liter. The main source of phosphates in sewage is, statistically, household wastewater and various industries, which use many synthetic detergents.

The problem of removing phosphates from wastewater has no optimal solution at this time and requires more research. Biological treatment of wastewater cannot achieve the required degree of contaminant removal, while the physical and chemical methods, while offering good results, require significant investment and create the problem of processing sediment, which forms in the process of chemical treatment.

Removal of Phosphorus From Wastewater. The biological method of phosphorous compound removal is based on the metabolism of biological sludge. Certain amounts of phosphorus are required for the formation of living cells, as well as a medium of transfer of energy, used to accumulate nutrients in a cell. The method of thorough removal of biogenic elements from wastewater is based on a traditional biological treatment combining aerobic and anaerobic processes. The biological phosphorus removal is based on the ability of several bacteria to accumulate soluble orthophosphates in cell in the form of insoluble polyphosphate. Oxidation of previously accumulated organic substances occurs in the aerobic part of the cell, and the energy is used by the bacteria to consume orthophosphate from the environment and turn it into polyphosphate to repeat the cycle of cell growth. However, the insoluble forms of phosphorus may hamper purification, since such compounds, in their solid form, cannot be consumed by microorganisms, thus requiring filtration or settling of the wastewater before biological treatment.

If the content of phosphorus is high, it may not always be possible to remove biologically. Chemical methods are used in this case. Reagent selection depends on its availability and cost in the area. The place of mixing the chemical with wastewater is determined individually based on previous laboratory research and later testing of the results in industrial applications.

Livestock Farm Wastewater Treatment

Farm Wastewater Treatment. The degree of contamination of wastewater is characterized by the amount of mineral, organic and bacterial materials solved or unsolved in the water.

Wastewater is treated by mechanical, chemical, physical or biological methods.

Biological processes involve oxidation of organic substances in waste water in the form of suspensions, colloids and solutions by microbes.

There are two type of facilities for biological treatment of wastewater. The first type are facilities where biological treatment occurs in conditions similar to natural (sewage farms, absorption fields and biological sewage ponds. The second type are facilities with artificial conditions (biological filters and aerotanks). The treatment process in the first group occur slowly, with the oxygen in the soil and in the water and due to the metabolism of microbes, which oxidize organic contaminants. Treatment is much more intensive in the second group of facilities.

Since the requirements to the degree of wastewater treatment keep growing, and biological treatment alone may not always be able to meet them, livestock farm wastewater must be processed additionally.

Treatment of such wastewater is a complicated process. It requires thorough consideration of the capabilities of each facility on a case by case basis. Methods used for such treatment are biological (biological ponds with natural or biological aeration) and physical and chemical (flotation, sorption and ozonation).

Every milliliter of livestock farm wastewater contains 10^8 of aerobic and up to 10^7 of anaerobic bacteria, therefore thorough decontamination must precede release of the water into water bodies or into sewage farms.

Biological wastewater treatment facilities are available to large livestock farms, but even their wastewater does not meet the purity requirements for release into water bodies. Purification of such wastewater is quite complicated. It requires two problems to be solved: technical and technological. The former occurs with pumping of wastewater and its mixing in tanks. The latter is related to the quality of processed water and the cost of its treatment. The cost of purifying highly concentrated wastewater from livestock farms with traditional treatment methods is defined by the energy cost of the process and the formation of large amounts of sludge.

Sometimes the problem of removing nitrogen and phosphorus from waste water arises.

Technical problems are solved by using modern equipment. For instance, for pumping of waste with high concentration of manure, hay or sand, submerged pumps with special wheels of various types are used.

The characteristics of wastewater must be taken into account, among them the concentration of suspended particles, abrasive particles, fibers etc.

For economical solution of mixing highly concentrated waste water, submerged mixers are used.

Aeration, the process of supplying oxygen to the biological processes, has always been problematic for livestock farm wastewater treatment. DUe to the high content of salts, organics and surfactants formed in the process of hydrolysis, the mass transfer of oxygen is 40% slower than in fresh water.

For a time, these problems were addressed by using ejector aerators with submerged pumps.

They have since been replaced by submerged pneumatic/mechanical aerators, which operate on the principle of atomizing bubbles with consecutive horizontal stirring of the sludge with a powerful stream generated by the mixer.

This results in formation of very small bubbles and high oxygen saturation.

Biological treatment of livestock wastewater is performed in two stages. Removal of nitrogen and phosphorus is not provided for in such facilities, as a rule. The high energy costs and a large amount of sludge is an unavoidable part of wastewater treatement.

The development of pneumatic and mechanical aerators and their capability of stirring without air facilitates the process of nitrodenitrification with periodic aeration without additional equipment, to set up the aeration process when oxygen is available and stirring when it is not.

The new technology is based on nitrodenitrification (a biological method of nitrogen removal) and anaerobic treatment of wastewater.

In the process of anaerobic purification, fatty acids are removed, hydrolysis of organic material occurs with formation of ammonium nitrogen. The result is the growth of pH to 7.6-7.9, with the formation of magnesium-ammonium-phosphate, which settles on the walls of pipelines. Up to 80-90% of phosphorus is removed.

Biochemical Treatment of Wastewater: Anaerobic Process

Biochemical Treatment of Wastewater. Anaerobic methods involve treatment of wastewater without access to oxygen. Instead, methane fermentation is used. The advantage of this method is the high level of converting contaminants with the formation of biogas byproduct.

Wastewater contaminated by nitrogen compounds are converted in the process of denitrification by microbes (such as Paracoccus denitrsficans) with formation of gaseous oxide (NO2) and molecular nitrogen (N2) or ammonia (NН3).

The fermentation occurs in sealed methane tanks (septic tanks). These are air tight reactors filled with immobile biological sludge, sludge ponds or similar. Methane tanks not only treat wastewaste, but also generate gas, which has high calorific value.

The main parameters of anaerobic methane fermentation are temperature, amount of waste and the intensity of mixing the water with the sludge. It should be noted that it is impossible to achieve full fermentation of organic substances in methane tanks, since the process is slow and requires stable and favorable temperature conditions. The degree of organic decomposition in the result is 40% (with methane output of 70%). An important point about the anaerobic process is the slight increase of microbial mass (by an order of magnitude less than in aerobic conditions), it also does not require the removal of large amounts of biological sludge from the reactor.

Biochemical Treatment of Wastewater.. The products of organic destruction, which are formed in the first trophic level, function as substrate for second level microbes. The characteristics of the intermediary products of anaerobic fermentation depend on the composition of the initial contaminants.

Anaerobic oxidation, as a rule, is efficient for treatment of wastewater contaminated with large amounts of organic substances (it ensures decomposition of over a hundred organic compounds).

Wastewater Treatment: Aerobic Process

Aerobic process are based on the use of microbes which require constant supply of oxygen and the temperature of 20-40°С. Disruption of oxygen supply and temperature changes the composition and number of microbes. Purification of wastewater in aerobic conditions is performed by biofilters or by cultivation of microbes in biological sludge, in which biocenosis consists of various groups of organisms(bacteria, worms, fungi, algae etc). Biological sludge is an amphoteric colloid, in which рН = 4-9, and the dry material contains 70-90% organic and 10-30% inorganic substances.

The main goal of the aerobic process is the oxidative mineralization of  organics and transformation of reduced nitrogen to oxidized nitrogen (nitrification resulting in formation of nitrite and nitrate ions).

Aerobic biochemical treatment of wastewater removes organic materials using heterotrophic organisms, which feed on organic carbon (proteins, fats, hydrocarbons etc). The nutritional value of carbon varies depending on the properties of the organic substances, as well as physiology of the microbes. In microbial metabolism some carbon is oxidized to form carbon acid and then carbon dioxide. Some carbon atoms are reduced to radicals becoming part of the cell.

The biochemical destruction of organic substances occurs due to several consecutive reactions, which simplify the initial structure of the substance. For instance, the process of oxidation of hydrocarbons, fats and some amino acids results in the same “universal metabolite”, which completely oxidizes into carbon dioxide and water. Therefore, the mechanism of wastewater treatment is related to transformation of components into environmentally safe compounds. The energy exchange in bacteria is characterized by the intensity of oxygen consumption and exceeds that in the cells of higher plants and animals. Bacteria adapt to consumption of new organic substances better than other organisms.

MIcroorganism which oxidize carbon, live in the upper part of the reactor, while nitrification bacteria reside in the lower part, where the competition for oxygen and nutrients is higher.

The process of aerobic treatment is efficient because its products are low-molecular compounds (СО2, H2О). They cannot be further decomposed in a microbial cell and have no reserve energy to release.

Wastewater Treatment: Absorption Fields, Biofilters and Aerotanks

Wastewater Treatment:. Aerobic wastewater treatment methods is classified according to the type of reservoir where the contaminants are oxidized. The reservoirs can be such structures as absorption fields, ponds, biofilters and aerotanks.

The aerobic oxidation (mineralization) occurs in biological ponds due to the microbes, algae and higher plants. The small depth, no currents, abundance of microalgae saturating water with oxygen and simple organisms feeding on bacteria etc.

Cultivation of higher water plants in such ponds to absorb not only a large part of biogenic elements, but also toxic substances (heavy metals, oil, phenol, nitric compounds, pesticides etc) intensifies the treatment process. Using biological ponds, both household and industrial wastewater can be treated, included mining wastewater.

Absorption fields are special plots of land populated with aerobic microbes which biochemically transform biological contamination into water and carbon dioxide.

Wide use of biological ponds and absorption fields is limited by the seasonal variations, low throughput, as well as the large areas required, along with constant control of ground water level. Artificial reservoirs, such as biofilters and aerotanks do not have these limitations.

Biofilters are special biological reactors loaded with a filtering element, which is covered with a biological film.

Thanks to the biological film, which consists of microorganisms, intensive biological oxidation processes occur. The film plays the chief role in treatment of wastewater.

The contaminated water in biofilters passes through a layer of loaded material (crushed minerals, pieces of plastic, synthetic fabrics etc), covered with biological film. Unsolved contaminants, colloids and organic materials in the water are captured by the biological film and remain in the filter material. The thickness of the biofilm formed by the microorganisms depends on the mean surface area of the material, concentration of organic material and external factors. After die-off, the film is carried out of the reservoir with water.

If the average yearly temperature in the environment does not exceed +3°С, it is recommended to place biofilters indoors with heating, if the average temperature is higher, they can be operated without external heating.

Biofilters are rectangular or round with double bottom: the lower bottom is solid, the upper is perforated. In the course of filtration, microbial film grows on the surfaces of the filter. Air is supplied through the lower part of the filter in the direction opposite to the flow of water.

Processed water goes to a settling tank where particles of the biofilm are deposited. Immobilization of biomass cells facilitates several stages of purification, with specific types of microbes.

Aerotanks are homogeneous bioreactors. They are typically concrete rectangular tanks, 3-6 meters high, equipped with aeration devices and connected to a settling tank. Aerotanks are divided into three or four corridors by screens. The types of these reactors are defined by the method of oxygen supply, the design of the reactor and the volume to material load. Treatment of water in an aerotank occurs when aerated mixture of wastewater and biological sludge pass through the tank.

Biological sludge has a complex structure; it contains many microorganisms, (thread bacteria and nitrification bacteria) and simple organisms (infusoria), with ferments to remove contaminants from wastewater. The treatment process is the continuous fermentation of contaminants. Particles of the sludge, formed by thread bacteria, on the one hand form adsorption skeleton, around which flocсules form, and on the other hand prevent formation of foam and stimulate sedimentation. The simple organisms consume bacteria, clarifying the water.

After treatment in aerotanks, water goes to settling tanks, where bio sludge is sedimented and partially returned to the aerotank.

It should be noted that most biogenic elements required for the development of microorganisms (carbon, oxygen, nitrogen etc), solve and are concentrated in wastewater. When the concentration of one of the elements in insufficient, such as nitrogen, phosphorus, potassium, such element is added to the wastewater in the form of salts.

Industrial Wastewater Treatment

The volume of toxic waste has been growing in recent years, and the environment cannot cope on its own.

Large amounts of contaminants enter the environment with wastewater, including toxic ions of heavy metals. Reagents are used to purify wastewater and decontaminate concentrated solutions (electrolytes etc), neutralizing them and causing sedimentation of heavy metals with an alkaline agent. This method does not allow to achieve the required purity of the water, while generating solid insoluble waste, which is difficult to recycle.

To address the large number of issues related to resource saving and environmental protection from wastewater contamination, is the development of new technologies using compact wastewater treatment systems. In this case the complete treatment of wastewater containing heavy metals is more efficient. Instrument, chemical, engineering and other industries generate a lot of wastewater with heavy metal compounds.

The specific peculiarities of the vortex layer are well suited for treatment of wastewater containing hexavalent chrome and other heavy metals, which allows to significantly reduce the consumption of reagents, improve purification and make the process continuous.

Ferromagnetic particles inside the chamber of the AVS magnetic mill perform intensive stirring of reagents in the chamber. The impacts and friction pulverizes the materials to colloidal particle size. The resulting colloid metal is good reduction agent. At the same time, hydrogen forms due to electrolysis of water in the vortex layer. Both factors have significant impact on hexavalent chrome and other metal reduction. This ability allows to significantly reduce the amount of iron sulfide for chrome reduction and completely reduce chrome by the colloid metal and hydrogen alone.

The process in the AVS magnetic nano-mill lasts only a fraction of second, making the process continuous.

Intensive mixing of reagents and the influence of electromagnetic fields, as well as dispersion of the compounds makes the formed metal hydroxides more finely dispersed than the product of mechanical agitation mixers.

Mechanical devices require large footprint and significant invesment. The duration of the cyclic process while using this method is 30 to 120 minutes.

On the contrary, the AVS magnetic mill unit to remove chrome from wastewater by chemical reduction in alkaline media is equipped only with tanks for iron sulfide and lime milk with portioning pumps, one AVS mill and a filter or a waste collection vessel.

Compact Wastewater Treatment Facilities

The modern wastewater treatment infrastructure in cities is in many cases in poor condition, while the volume of wastewater and the concentration of contaminants keep growing. The quality of wastewater treatment may fall short of standards due to unsatisfactory operation of the aging treatment plants. Besides, new sewage lines must be built through residential area to supplement the existing infrastructure. The larger the treatment facilities, the mode costly are maintenance, repairs and operation, which becomes so cumbersome that the expenses keep growing indefinitely.

Another unpleasant issue is that with the growth of aeration facilities, the amount of bio sludge and the area of the facilities grow proportionately. In large cities treatment facilities may take up as much as 1000 hectares.

Compact treatment facilities can help avoid these drawbacks, while using new technology allows to improve treatment quality to meet the highest standards.

Biochemical methods, apart from mechanical, chemical and biological, are considered the most promising.

Three types of bioreactors are used in local systems for deep wastewater treatment: biofilters, aerotanks and sewage farms. Among them are biogilters with sand and biofilm, used in the US, the UK, Japan and France.

The gravity feed of wastewater in combined biofilters eliminates the need for pumping stations and separate buildings with heating and lighting.

High parameters of wastewater treatment may be received by a compact system with submerged biosludge membranes, which consists of separate anaerobic-aerobic treatment chambers, due to the passage of wastewater from the bottom to the top through the biomass. This technology also allows to produce biogas.

Another compact option with good treatment quality are two coaxial polyethene cylinders. The ring between the cylinders is separated into zones by radial screens, and wastewater flows through them consecutively. The various facilities combine various levels of treatment: destruction of arganic compounds, nitrification, denitrification, microfiltration etc.

Biochemical treatment of household wastewater is performed in vertical rectangular tanks, with a four sided pyramid in it. The space between the rectangle and the pyramid is the aeration zone, while the space in the pyramid is the secondary settling tank. Bio sludge returns to aeration zone through four slots in the bottom.

Operation of small treatment plants is prone to sharp variations in flowrate and contaminant concentration. To compensate for this and to ensure a more even supply of water for treatment, an equalization tank is recommended. Wastewater from several buildings can be treated in a single structure of several concrete modules. The first module performs as a collector and settling tank, the other performs aerobic oxidation of organics and ammonia nitrogen, the third module performs denitrification. Excess biomass is supplied into the first module for stabilization with primary sediment.

A final treatment section can be added to the system for better treatment, where water passes through layers of filtering material with decreasing mesh. The processed water is decontaminated by UV-light.

Ion Exchange in Electroplating Wastewater Treatment Processes

The problem of contamination of water bodies with biogenic elements and protection of the environment is essential. The main source of contamination, which worsens water quality and disrupts ecosystems is the release of insufficiently treated wastewater.

Municipal treatment facilities, where biological treatment of water is performed through the traditional arrangement of aerotank and a secondary settling tank, cannot ensure high enough quality of the processed water to meet the requirements sufficient for release into water bodies, due to high concentrations of various forms of nitrogen and phosphorus.

The reasons of low efficiency of treatment plants are many: design flaws, obsolete technology, incorrect operation, water and contaminant composition different from anticipated due to the development of the industry.

The solution to the problem of pollution by inefficiently treated waste is to reconstruct most of the sewage facilities using advanced technology and new wastewater treatment developments. Most attention is now directed at processes, which can simultaneously remove phosphorus and nitrogen from wastewater. Considering the environmental factors, removal of nitrogen and phosphorus using biological denitrification and biological dephosphorization.

Removal of biogenic materials from wastewater can be done in several ways. All methods are divided into anaerobic, anoxic and aerobic.

Three areas must be created in aerotanks for biological denitrification and dephosphorization:

  • aerobic (high concentration of solved oxygen), with removal aerobic removal of organics, nitrification (biooxidation of ammonia nitrogen to nitrate nitrogen) and dephosphorization (rapid consumption of phosphates by bacteria);
  • anoxic (practically no solved oxygen, but nitrates and organics are present), with denitrification;
  • anaerobic (no solved oxygen, no nitrates and nitrites, organics present), with fermentation of organics to acetate, consumed by bacteria with formation of phosphates.

Anoxic and anaerobic conditions are created by changing aeration to mechanical agitation, although such reconstruction is costly for existing facilities. There is an alternative: to create anoxic conditions in the aerotank by low (the minimum required to prevent settling of biological sludge) intensity of aeration.

For existing aerotanks in traditional aerobic mode, implementation of biological denitrification and dephosphorization while keeping treatment capacity requires intensification of purification. Increasing the rate of aerobic process, including nitrification and biooxidation of organics, can reduce the volume of aerobic zone to allocate space in the tank for anoxic and anaerobic zones.

Treatment of Agricultural Wastewater with Biotechnology

Treatment of agricultural wastewater usually involves physical, chemical and biological processes. A typical treatment system includes primary, secondary and, in some cases, tertiary purification stages.

The principle of operation of most one or two stage treatment plants is based on using physical (mechanical) effects, and therefore the variety of the facilities does not differ much in terms of construction and operation costs. In turn, secondary treatment plants can be divided into two large groups: traditional and alternative (close to natural conditions), which differ very much in terms of construction and operation costs.

Secondary treatment involves removal of suspended substances, solved organic and biogenic materials from wastewater, and is performed by microbial transformation and assimilation.

Treatment of agricultural wastewater. This biological process, which is performed by bacteria and fungi, the development of which is artificially stimulated in special tanks or depressions in the ground, which may be equipped with devices for mixing, aeration or additional surfaces for immobilizing and development of the biomass.

The traditional biotechnology which can be used for secondary purification of wastewater are:

  • aerobic systems with suspended microbes, also known as biosludge systems (aeration basins with sludge recirculation – aerotanks; cyclic reactors – SBR; membrane bioreactors – MBR; oxidation ditches);
  • aerobic systems with immobilized microbes (trickling filters – TF; rotating biological contactors – RBC).

Alternative (near-natural) biotechnologies which can be used for secondary treatment of wastewater, are:

  • waste stabilization ponds;
  • aerated ponds (lagoons);
  • constructed wetlands.

Traditional and Alternative Methods of Household Wastewater Treatment

Methods of Wastewater Treatment. Among the traditional wastewater purification technologies, one of the most common is aerotank treatment.

Those are, as a rule, rectangular reactors with many chambers, which contain high concentrations of aerobic microbes in suspended floccules (biological sludge) and are equipped with a system of continuous aeration and recirculation of sludge. Aerotanks with prolonged aeration promote the development of bacteria which can effectively remove organics, as well as oxidize ammonia nitrogen to nitrates.

For complete removal of nitrogen from wastewater after nitrification, anaerobic denitrification is required by installing additional vessels or creating special chambers in existing ones.

Phosphorus can be removed by chemical sedimentation or microbial assimilation.

Single reactor systems are also widely used in the world: sequencing batch reactors and membrane bioreactors, as well as oxidation ditches.

The other type of devices are systems with immobile biomass (biofilm). These include trickling filters and rotating biological contactors.

Methods of Wastewater Treatment. Trickling filters are usually cylindrical vessels filled with natural or artificial materials with high mean surface area, on which aerobic and anaerobic bacterial proliferate, and which is in contact with wastewater. Rotating biological contactors consists of several disks up to 3 meters in diameter, installed vertically on a horizontal shaft and submerged (35-40%) into wastewater.

The biological purification of wastewater can also be performed in conditions close to natural. One of the simple methods that can be used for secondary treatment of wastewater is the biological pond. Stabilization ponds are usually artificial rectangular ponds (without higher plant life), connected in a three level cascade: anaerobic pond (2 – 5 meters deep), optional anaerobic pond (1-2.5 meters deep), and an aerobic pondа (0.5-1.5 meters deep). These systems are constructed in at least two parallel lines. Minimum temperature for operation is 8°С.

Stabilization ponds can also be equipped with aeration devices (mechanical aerators usually), which improve the efficiency of purification and makes it possible to use the ponds in lower temperatures.

Another technology of the same nature is the ponds with horizontal subsurface flow of wastewater. They consist of a reservoir covered by watertight material, a layer of filtration material (gravel, sand etc), higher plant life and waste water that moves mostly horizontally below the filter layer.

Dry grinding of paint pigments using electromagnetic nano-mill by GlobeCore

grinding of paint pigments

grinding of paint pigments

Expanding the application areas for the electromagnetic nano-mills (AVS), GlobeCore engineers conducted tests in dry milling of paint pigments.

Pigments and fillers perform an important function in paints and varnishes. First of all, pigments provide the variations of color and color shades. Second, they form a film layer, making the coating more durable. And third, the pigments improve anticorrosive properties of paints and lacquers.

Paint pigments are divided into two groups: mineral and organic. Mineral pigments, in turn, are natural or artificial. Natural mineral pigments are obtained by crushing and refining of various ores and clays, such as light gray, white chalk, green glauconite, dry yellow ocher. Artificial mineral pigments are produced by chemical processing of mineral raw materials. Organic pigments are materials of organic origin.

Each pigment has certain properties. The most important property is the fineness of grinding, which also influences paint spreading and tinting strength. Paint spreading is calculated in square meters per liter and the tinting strength is the ability of the pigment to change the color of another pigment. Increasing the fineness of grinding automatically increases paint spreading and tinting strength.

To obtain an alkali-resistant paint, GlobeCore performed mixing and regrinding of  pigment components: silicon, aluminum, zinc and zirconium.

Initially, the selected degree of grinding was more than 50 microns, and the mixture itself was not homogeneous.  To achieve better results, it was decided to try a finer grinding  and regrind 500 g of the mixture to less than 10 microns to achieve a homogenous state. The grinding was performed using ferromagnetic steel particles 400 gr each, for 30 minutes, at the temperature of 90 … 100 ° C. The mixture changed color from bright red to pale pink due to the finer grinding of components.

The results of the experiment, its details and conditions can be found in the video report.

Equipment for Mixing of Paints

http://avs.globecore.com

The need for mixing different paints arises when one needs to perform some paintwork, but is not satisfied with standard colors available in the market.  In addition, mixed colors are more subtle and convincing.

Let us consider the basic techniques used in paints mixing, as well as the equipment used for this purpose.

There are the so-called basic colors, which cannot be obtained by mixing others.  These are red, blue and yellow.  Mixing these colors, we get complementary colors: green (blue + yellow), purple (blue + red), and orange (red + yellow).  The main difficulty in this case lies in basic colors not being absolute, i.e. there are different shades of them.

Complementary colors are mixtures of two other colors.  When adding a third color, a mixed color is obtained.

In order to mix paints, different equipment can be used, but not all equipment can to give the expected result.  Electromagnetic mills provide dispersion of solid particles with simultaneous particle activation.  This feature can be used for mixing of paints very efficiently.  The process of pigment grinding is accomplished simultaneously with the process of ferromagnetic particle surface grinding.  This is not applicable for white or light-color paints.  However, metal additive does not impair the properties of paints of different colors, moreover, it can even improve them.  The devices were tested on mixing of water-based paints, which contain chalk, talc, titanium dioxide and ultramarine.  Tests have shown that paint can be prepared by several minutes of treatment in the vortex layer.

Filtration of Vegetable Oil

Filtration of Vegetable Oil

Vegetable oil is a product made from oily raw material by extrusion and extraction processes.  A combination of these methods is used slightly less often: the first stage is extrusion, and the second one is extraction.

The extrusion process involves pressing of oily raw material from pre-treated sunflower seeds.  Extraction is based on diffusion and involves recovery of oily material using extraction hexane.

Oil extraction is preceded by cleaning the seeds from various impurities, peeling the seeds and grinding, which ends with obtaining seed meal.

Thereafter the meal is subjected to hydrothermal treatment, which involves humidifying and heating in scrubbers or steaming.  The final product of such hydrothermal treatment is pulp.  It is much easier to get oil from pulp.

Pressed oil almost always contains various impurities, which significantly reduce the quality of the product and their presence is undesirable.  Vegetable oil must be filtered.

Filtering can be of mechanical type, when suspended particles of impurities are removed from vegetable oils.  Usually this is done by settling or filtration through special cotton cloth in filter presses.  It is also possible to use centrifuges.

In addition to mechanical filtration, refining of sunflower oil also includes hydration, winterization, bleaching, deodorization and polishing.

Hydration is a method for removing phospholipids, protein and mucous substances.  It is never used independently, but in combination with settling.  Initially oil is treated with a small amount of hot water, and then precipitated impurities are removed by settling.

Winterization is necessary to remove waxes and wax-like substances from vegetable oils.

Neutralization is the process of oil treatment with a water solution of sodium hydroxide.  This process is based on the ability of free fatty acids to react with alkali to form water solutions of soap, also referred to as soap stock.  The latter are oil-insoluble substances that are deposited on the bottom and can be easily removed from the product.

Adsorptive refining is also called bleaching.  The second name arises from the nature of substances removed during oil processing – fat-soluble pigments (chlorophylls, carotenoids, etc.).

Oil bleaching occurs under vacuum at a temperature below 75-80ºC.  Bentonite bleaching powder is added to the treated product and the mixture is stirred for 20 to 30 minutes.  This time is usually sufficient for adsorption of coloring substances from the oil.  After this, the oil requires sedimentation and filtration on filter presses.

Deodorization is a distillation process for removing odorous substances from the oil; these substances include low molecular weight fatty acids, aldehydes, ketones, and other products that affect the taste and smell of oil.  Deodorization is also necessary to remove polycyclic hydrocarbons, toxic products and pesticides. The process itself takes place in vacuum by blowing superheated water steam through oil.

Complete refining of vegetable oil is not always necessary.  But filtration is always required.  When grinding sunflower seeds it is practically impossible to obtain raw material completely free of impurities.

During oil filtration, great attention should be paid to technical operations associated with mechanical mixing of the components.  Conventional equipment used for this purpose is unable to provide the necessary contact between components, resulting in excess expenditure of raw materials and inability to provide the necessary stability and quality of refining.  A good alternative is the use of the so-called magnetic mill.  The specifics of their operation (the combined effect of a vortex layer and a magnetic field of the inductor) can intensify the process of mixing of the components, thus creating the necessary conditions for effective flow of oil degumming process.  You can find more detail on tests conducted in the article “Purification of vegetable oils using AVS”.

The Use of Vortex Layer Devices for Decontamination of Liquid Pig Manure

One of the major problems of livestock industry is the accumulation of large amounts of liquid manure.  Manure processing and subsequent disposal technology depends on the pig farm cleaning methods.  Nowadays, water wash is most often used in practice, which is characterized by the occurrence of low-concentration manure effluent, the volume of which is 4-5 times more than the volume of the initial material. Processing costs also grow proportionally.  At the same time it extends the life cycle of various infectious diseases and helminth eggs, which requires effective ways of disinfecting the resulting manure.

Traditional approaches are used mainly for litter manure and are unacceptable for liquid effluent in terms of economy and sanitary, because they can cause mass spread of infectious diseases of humans and animals.

The use of magnetic fields for liquid pig manure treatment gives the highest technical and economic effect resulting from the absence of necessity to use reagents, reduction of the amount of deposits and efficient treatment facilities operation.

Manure which has been disinfected in such a way meets all environmental requirements and can be successfully used as an organic fertilizer.

Technically, disinfection of pig manure is performed in special AVS-100-type vortex layer devices.  By means of selecting the optimal mass of ferromagnetic elementsin the active zone of the machine, as well as adjusting the ferromagnetic particle length to diameter ratio, it is possible to achieve optimal performance of disinfection.

Electromagnetic nano-mill technology for diesel desulfurization

diesel desulfurization

diesel desulfurization

Oil contains many different chemical components and elements, sulfur one of the them.

Sulfur in oil can be in pure form or in the form of volatile sulfur compounds: sulfides, hydrogen sulfide, disulfides and mercaptans with high corrosive and aggressive effects, therefore not allowed in commercial petroleum.

A special measurement was introduced to characterize the level of sulfur in fuel, called sulfur mass fraction. Nowadays the requirements for the sulphur mass fraction in petroleum products are quite strict and continue to tighten. It is due to the poor environmental situation, deteriorating due to toxic gas pollution and combustion of sulfuric fuels.

For desulfurization of petroleum products, the industry uses the processes of catalytic hydrofining, biodesulfurization and oxidation of sulfur compounds. As a result, fuels have limited sulfur content. For example, acceptable limits of sulfur for Euro-2 fuel is 500 mg / kg, for Euro 3 fuel it is 350 mg / kg, Euro 4 it is 50 mg / kg and Euro 5 it is 10 mg / kg.

Almost all transportation companies and organizations whose work is directly connected with operation of motor vehicles are looking for ways to save money on fuel and lubricants. One of the possible ways to save money is to buy cheaper oil and desulfurize it to acceptable levels according to standards.

For autonomous fuel desulfurization, GlobeCore proposes a new technology process implemented in the AVS-150 and UVR units. The electromagnetic nano-mill intensifies the mixing process of the reagent with diesel fuel.

The tests achieved reduction of sulfur content in diesel fuel from 337 to 8 mg / kg, while retaining other important characteristics such as flash point in closed cup, fractional composition, etc.

Learn more about the experiment and its results in more detail in the video report.

Magnetic mills in production of aluminum powder from aluminum-containing waste

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GlobeCore engineering department continues the testing of vortex layer magnetic mills to expand the possible applications of the device.

This time, the research focused on pulverization of salty aluminum waste into powder. This type of waste is formed by aluminum and aluminum alloy production, processing and molding.

Aluminum powder has many industrial uses due to its properties, such as high reactivity, high combustion energy, corrosion stability etc. The material can be used in pyrotechnics, chemical production, metallurgy, petrochemical industry and other areas. It also serves as pigment in dye production.

The possibility of making aluminum powder aluminum-containing waste was tested in the AVS-150 magnetic mill with the use of dipole steel ferromagnetic particles. The desired result was achieved in thirty minutes of processing.

Using the AVS for powdering of aluminum waste allows to solve the issue of handling environmentally hazardous aluminum waste and to replace the costly gas generator in production of aerated concrete.

You can see more of the experiment in the video below.

Quartz sand pulverization

Quartz is a natural mineral. It is widely availalbe and has several important properties: high strength, resistance to destruction and high sorption capability. Quartz can be a part of other minerals, making its content in the planet’s crust above 60%. It is mostly used as sand in industrial applications.

Fine pulverization of minerals allows to change their adsorption capacity and intensify processes. Due to fine and superfine grinding, the material’s properties change.

Applications of quartz sand

Quatz sand is widely used. It is stable to chemical, mechanical and atmospheric factors and has good flowing properties. This material is used for:

  • asphalt felt production;
  • textured fininsh production;
  • fire-proof material production;
  • steel production;
  • application on yards and lawns;
  • production of casts for steel production;
  • metal corrosion removal;
  • paint production;
  • filtration of drinkable water and industrial waste water;
  • production of fine concrete and polymer concrete;
  • production of glass and fiberglass.

Quartz sand production

Quartz sand can be produced either artificially or naturally. In the latter case, the material is taken from quarries, in the former case minerals are ground, refined and sieved.

While choosing a method of quartz pulverization, it should be remembered that each industry requires certain granule size, smoothness, color etc. For instance, decorative use in architecture requires smooth average and small size granules, while sanding requires jagged granules.

Jet mills are used for fine grounding of material up to 3 micron. The principle is of colloding two air jets carrying the material. The material is pulverized due to the collision impacts and friction.

Vibration mills are used for grinding of particles in the range of several millimiters to several micron. They consist of the grinding chamber with a vibration device inside. The rotation of the vibrator shaft causes the chamber to move on a circular path. The internal surface of the chamber and the external surface of the vibrator transfer this motion to the particles. Collisions of the particles create tension changing the structure of the material and promote its interaction with the medium filling the space in between. The main drawback of the vibration mill is the deterioration of the body due to wear along with grinding of the particles. This means that not only the equipment service life is reduced, but the material becomes contaminated by wear products.

Planetary mills perform fine and superfine pulverization of materials. The device consists of 3 or 4 drums, rotating relative to the central axes in the direction opposite to the rotor.

All advantages considered (high mean capacity, high energy and intensive pulverization) planetary mills also have drawbacks. The main issue is the scaling problem, high wear and their use mostly for wet grinding.

GlobeCore magnetic mills

As an alternative to the above methods of quartz sand production, GlobeCore offers magnetic mills, the AVS-100 and AVS-150 vortex layer devices. THe vortex layer is created by three phase electric power. The system resembles a cage motor without the rotor, with the active chamber in its stead. The chamber is filled with the material for processing, along with ferromagnetic pellets, which interact with the rotating EM field.

Chemical and physical processes in the vortex layer devices are intensified and accelerated due to the intensive disperion and mixing of the processed material, acoustic and electromagnetic influences, high local pressures, electrolysis and other factors. All of the above processes occur in the same chamber, in the same mode of operation.

The vortex layer devices can easily be integrated into existing process lines to improve product quality. Arranging connections accordingly (consecutively or parallel), just about any production rate can be achieved.

Tests indicate that pulverization of 200 grams of quartz sand to 1 micron only takes 2 minutes in the vortex layer. The size of the ferromagentic elements used was 3 mm, with the total particle load of 300 grams.

Advantages of GlobeCore Magnetic Mills in Processing of Diamonds

Diamonds that are mined from Earth’s interior can be divided into two groups: industrial and jewelry. Industrial diamonds can be of high and low quality. High quality industrial diamonds are used in drill bits without preliminary processing. Low quality industrial diamonds require some manipulations to be done that can split the diamonds according to their shape and size, as well as strength characteristics. In particular, we are speaking about selective crushing, ovalization, polishing and thermal processing.

Selective crushing of diamonds can be implemented through the influence of mechanical stress, which destroys the weakest grains. The main disadvantage of units that operate based on the mechanical method is the uneven distribution of the breaking stress, which has an impact only on some parts of diamonds. Therefore, upon completion of the process the outgoing material may still contain some weak grains. In addition to that, the mechanical method of processing diamonds does not provide a high efficiency of the crushing process.

The GlobeCore AVS vortex layer unit eliminates the mentioned disadvantages in selective crushing of diamonds. The principle of operation of the unit is as follows: feedstock is fed into the cylindrical tank of the unit. The inductor creates a rotating electromagnetic field. The ferromagnetic particles, which interact with the rotating electromagnetic field of the inductor, are also placed together with the diamonds in the working chamber of the apparatus.

Processing of the diamond feedstock in the vortex layer of ferromagnetic particles can reduce the number of large and increase the number of small diamonds. Moreover, there is a significant increase in the strength of the processed grains and their ovalization.

Vortex layer devices are characterized by a high reliability of their performance and can be easily installed in industrial facilities that have no special foundations. Proper placement of the device (sequential, parallel, and other) enables you to get virtually any efficiency of the diamond selective crushing line.

Grinding (Crushing) of Fluoroplastics

Fluoroplastic – is the general name of fluorine-containing polymers. According to the existing classification, substances of this class include:

  • polytetrafluoroethylene;
  • polytrifluorochloroethylene;
  • polyvinylidene fluoride;
  • copolymers of fluorinated ethylene.

Fluoroplastics have an excellent chemical inertness towards corrosive media. The exceptions are molten alkali metals and chlorine trifluoride.

Fields of Application of Fluoroplastics

Due to its physical and chemical properties fluoroplastics are widely used in industry, medicine, transportation, energetics, and also for solving military tasks.

Chemical inertness towards corrosive media promotes the use of fluoroplastics as structural materials for chemical instrumentation. Also, they are useful for manufacturing pipes and vessels intended for pumping and storage of highly aggressive liquids.

Fluoroplastics are characterized by a low friction coefficient, which allows to widely use this construction material in mechanical engineering. For example, fluoroplastics in friction assemblies improve the reliability and durability of industrial machinery by being able to operate even in aggressive environments, cryogenic temperatures and high vacuum.

At the same time fluoropolymers have good dielectric properties and high heat resistance. Due to this, they are used in electrical and radio engineering for insulating cables, wires and connectors, producing printed circuit boards, as well as slot insulation of electrical machines. To obtain high-quality secondary products from waste fluoroplastics, it is necessary to crush the feedstock to a particle size less than 200 microns.

Methods of Grinding of Fluoroplastics

The mechanical method of grinding is based on the use of impact mills. In this case, material of the required size is obtained by sequential application of static and dynamic loads, thereby creating stresses in the material, which excess the internal cohesive forces between the particles. Dynamic impacts, such as a stroke, are more suitable for fluoroplastics.

The complete grinding process of waste fluoroplastics is as follows:

  1. coarse crushing to a particle size of not more than 3-5 mm;
  2. additional processing of the material obtained after the first stage in order to give it the required brittleness;
  3. grinding to a particle size of not more than 200 microns;
  4. screening of the ground fluoroplastic for selecting a certain fraction (if necessary).

Grinding of Fluoroplastics in Vortex Layer Device

GlobeCore suggests using vortex layer apparatuses to intensify the process of grinding fluoroplastics. The principle of operation of this equipment is based on converting the energy of an electromagnetic field into other forms of energy directly in the area of processing. The vortex layer device consists of the working chamber with a diameter of 60-330 mm, and the inductor of rotating electromagnetic field. In the working chamber there are cylindrical ferromagnetic elements of the required diameter and length. Depending on the volume of the working chamber the number of such particles can range from a few dozens to a several thousands of pieces. Under the influence of rotating electromagnetic field the ferromagnetic elements begin to rotate in the working chamber and form a so-called “vortex layer”.

By using the vortex layer device for grinding fluoroplastics you are able to obtain the required particle size for significantly less time than when using alternative approaches. This result is achieved through a number of effects that take place in the working chamber of the machine, such as:

  • intensive dispersion;
  • acoustic and electromagnetic treatment;
  • high local pressure, and other.

Advantages of GlobeCore Vortex Layer Device (Magnetic Mill) for Wastewater Cleaning

Despite of all the efforts to achieve progress in  improving the environment is not yet possible. Therefore, it is urgent to find a new high-performance solutions for treating sewage of  industrial enterprises.

Existing wastewater treatments are not always able to remove all hazardous chemicals. GlobeCore specialists conducted a number of studies confirming that – using  physical fields is quite a promising approach to cleaning and disinfection of wastewater.

GlobeCore has developed and produced vortex layer units using the energy of rotating electromagnetic fields for  industrial wastewater treatment.

This device consists of an inductor, a working chamber and ferromagnetic particles (needles). The working chamber is a smooth tube, inside which there is a rotating electromagnetic field,  induced by inductor. Ferromagnetic particles entering magnetic field, themselves become magnets. Needles begin to rotate, but their movement is constantly disturbed by collisions with each other and with the walls of the working chamber and particle materials. It is the energy and movement of ferromagnetic particles that has a great influence on the course of technological processes. Also, the needles cause an  acoustic wave, and liquid – the phenomenon of cavitation. This makes it possible to achieve a number of effects:

  • Destroy  solid mass;
  • Emulsify liquids;
  • Paint dispersing;
  • Change the course of chemical reactions.

In an external alternating magnetic field, ferromagnetic particles acquire a certain charge, which continuously changes. If there is water in the working chamber or other liquid, it causes electrolysis. And due to the large number of needles electrolysis occurs substantially throughout the working chamber of the machine.

The processes occurring in the working chamber of magnetic inductor are:

  • Restoration of compounds;
  • Oxidation;
  • Partial decomposition of water (ionization);
  • Metal depositions in a form of  the solution as a hydroxide;
  • Partial decomposition of organic compounds with complex polyatomic molecules;
  • Disinfection of water.

Combination of these phenomena in a relatively small workspace  is capable to  accelerate all mechanical-physical and physical-chemical reactions in hundreds of thousands of times, which is equivalent to a proportional  increase in productivity of a production  line.

GlobeCore Vortex layer device magnetic mill AVS-100/150  clean waste water, which include nickel, lead, chromium, copper, iron, manganese and other heavy metals, as well as phenol, tianity and cyanates, nitro compounds, arsenic, organic connections, etc.

Studies have shown that the use of GlobeCore vortex layer devices in production lines for industrial wastewater treatment allows you to:

  • Reduce power consumption 2ce;
  • Reduce reactants used 2-10 times;
  • Reduce  temperature of the reaction;
  • Reduce the area of wastewater treatment plants by 10-15%;
  • Speed up chemical processes to hundredths of a second.

Types of wastewater, for  vortex layer device magnetic mill AVS-100/150.

Wastewater treatment from hexavalent chromium and other heavy metals

Using vortex layer devices  to treat this type of wastewater can make it a  continuous cleaning  process. Recovery of chromium lasts no longer than a second, which improves the overall performance of the processing line. Deposition of the solid phase particles after the reaction  goes 1.5-2 times faster than in conventional devices with a stirrer. Furthermore, when processing vortex ferromagnetic particles layer can be obtained more dispersed metal hydroxides.

Wastewater treatment from phenol

When using magnetic mill AVS 100/150 in technological lines in wastewater treatment from phenol – it is possible to reduce operating costs. Full cleaning is achieved within 0.1-2 seconds at the current temperature of wastewater from 20 to 45 ° C. The corresponding figures of traditional approaches are 3-5 hours and 95-100 ° C, respectively.

Wastewater treatment of cyanide compounds

The vortex layer machine oxidise cyanide and decompose it to carbonate and ammonia in one step in an alkaline environment at pH 9-10.

Also, the benefits of  magnetic mill AVS-100/150 – the quality achieved is not based on its concentration in wastewater.

Wastewater treatment from fluorine and nitro compounds

In the case of wastewater with fluorine content of nitro compounds – the use of vortex layer devices significantly simplify technological lines and improve the quality of cleaning. The control measurements showed that the output of the magnetic mill AVS fluorine concentration in the wastewater does not exceed the limits.

GlobeCore equipment performance in this case is about 30 000 m3 / h per 1 m3 of working volume. Traditional performance of reactor cascade does not exceed 0.25 m3 / h per 1 m3 of the working volume.

Wastewater treatment from arsenic

The magnetic mill AVS-100/150 totally clean wastewater from arsenic in 1-5 seconds. Thus reagent consumption is reduced in 3-5 times compared with conventional technologies. In addition, the use of vortex layer devices helps to make the process continuous and significantly simplifies the process diagram.

Wastewater treatment in enterprises, specializing in the production of fodder yeast

To date, for disinfection of sewage of industrial enterprises specializing in the production of fodder yeast, used mainly biological methods. But they are not without certain disadvantages, which are  non-compliant to the existing degree of disinfection of the current regulations, have large operating costs and power consumption.

Using vortex layer apparatus can accelerate physical and chemical processes of mash treatment, due to the intensive mixing, dispersing, acoustic and electromagnetic treatment and electrolysis.

Magnetic mill AVS-100/150 gives better quality of cleaning compared to industrial fermentors oxidant even with a smaller air flow

Vortex Layer Device(Magnetic Mill) AVS Treatment of Containing Cyanide Wastewater from Galvanic Plant

A huge amount of water is consumed in electroplating workshops. Most of the volume is used to prepare and adjust electrolyte and  for rinsing products after processing.

Depending on the type of contaminants the wastewater from electroplating plants  is divided into three groups:

  • The acid-alkaline water. It contains acid (sulfuric, hydrochloric, nitric, hydrofluoric), alkali and heavy metal ions (copper, nickel, cadmium, iron, zinc, tin, lead). pH indicator for such drainage ranges 1 -10;
  • Cyanide-containing wastewater. It contains free cyanide, zinc cyanide compound, copper, cadmium and various salts. Acidity of cyanide drains usually exceeds mark “7”;
  • Chromium-containing water. The composition of chromium-containing drainage include trivalent chromium, iron, zinc, copper, nickel, chromates and acids. The acidity of wastewater can vary from 1 to 7.

Neutralization of cyanide and chromium-containing wastewater is recommended to be done separately as they release toxic hydrogen cyanide in the case of co-processing. The same reason prevents mixing cyanide containing wastewater with acid.

Cyanide wastewater treatment may be achieved using reagent, ion exchange or electrochemical method. Also possible to use ozonation and hyperfiltration.

In fighting cyanide more commonly is used a modification of reagent and electrochemical methods. Modified reagent method chemically converts highly toxic cyanide into non-toxic and manageable products. For oxidation there are used KMnO4, H2O2, O2, O3 и Cl.

Already there are successful experiences in the application of vortex type grid chambers  in wastewater treatment processes. Their effectiveness is  due to a number of factors:

  • Electromagnetic treatment and substance activation;
  • Dispersing phase;
  • Operation of the vortex layer, its hydrodynamic factors that provide an intensive mixing of the processed materials.

Various waste compositions require further testing to investigate the effectiveness of performance and future application in each separate case.

GlobeCore cleaned cyanide-containing wastewater sample on the vortex type machine magnetic mill AVS 150. 0.5 L of water was taken with 250 g of dipole particles of ferromagnetic steel 08G2S 2 mm diameter and 20 mm long. The reagent used – was sodium hypochlorite NaCl with active chlorine concentration of 190 g / l. The initial zinc content in the drainage was 24 mg / l.

Then 66 mg of sodium hypochlorite was added to the liquid to be processes with, representing 100% of the stoichiometric ratio. The level of acidity during cleaning process was pH = 10.4. The processing time in the machine was 3 seconds.

After cleaning , the results showed :

  1. cyanide content of less than 0.005 mg / liter;
  2. the chlorine residue content  is less than 2 mg / l.

To compare the results achieved using  magnetic mill  GlobeСore AVS-150, a similar experiment was conducted with a stirring device. It was  established  that using vortex layer unit completes the deposition of cyanide in less than an hour, and  using a stirring device  – more than six hours. The sediment obtained by treating wastewater in the vortex layer unit, proved to be more dense, due to the magnetization of the ferromagnetic ground particles.

Chlorine content in the drainage after a stirring device was 6 mg / l, which is three times more than  after  magnetic mill AVS-150.

cyanide wastewater treatment avs 150

cyanide wastewater treatment

Regrinding wood flour

Wood flour is a powder consisting of particles the size of hundred microns, and obtained by pulverizing sawdust.

The area of application of wood flour is rather wide This material is used in the preparation of phenolic plastics, alkyd linoleum, filter elements and explosives. In smaller amounts wood flour is used in the manufacture of electrodes, adhesives, catalysts, and casting molds.

Production technology of wood flour:

  1. Preparation of raw material. The basic raw material can be sawdust, wood shavings or crushed wood. First it is sorted: the bark and large inclusions removed
  2. Grinding raw material in order to adjust the size of its particles.
  3. Drying the raw product to provide better breaking.
  4. Grinding.
  5. Sorting.
  6. Packaging.

Today there is a lot of equipment available on the market that can solve the problem of grinding  natural raw material. But the majority of the mills are morally and technically outdated. High power consumption makes the use of such equipment unprofitable at current energy prices.

For a long time the leading role in grinding wood flour performed  hammer mills. Devices of this type operate on the basis of impact. This principle is well suited for rough grinding of fragile materials of polycrystalline structure and not for  fine-disperced powders made out of wood. Moreover, the increase in moisture on 13.8 – 20% in raw material reduces crushing productivity by nearly 30% increasing power consumption by as much.

Repeated attempts to replace the hammer crushers with vibrating and jet mills did not bring tangible results.

A promising direction in obtaining fine-dispersed fillers out of natural raw materials is – to use a vortex layer of ferromagnetic particles created by  electromagnetic field.

Vortex layer unit intensifies the process of regrinding wood flour,  by intensive dispersion and mixing of the particles, treating them acousticly and electromagnetically with the high local pressure and electrolysis etc. The resulting product has the desired degree of dispersion, and can be used according to purpose.

Vortex layer devices are reliable and can be easily installed in the premises without special foundations. When choosing a required arrangement (in sequence, parallel, etc.), almost any production line for fine-dispersed wood flour could be achieved.

Vortex layer device for fine-dispersed chalk production. Grinding process

Chalk regrinding  in the vortex layer device

These devices – are a complex interaction between the particles, that are a result of rotating electromagnetic field, fluid and processed material. The process of grinding and mixing is speeded up.

avs

The grinding effect is determined by the nature of the movement of ferromagnetic elements in the working chamber of the device – in a free collision of particles with the ferromagnetic elements, and  constrained collision between two elements or elements and the chamber.

GlobeCore perfected this technology and launched production of vortex layer devices AVS 100 and AVS-150, to be used in production of fine-dispersed chalk – and in regrinding the raw materials.

Quartz sand granulometric composition after grinding in the AVS

Initial fraction size, micron Amount of sand of the fractions, %,
depending on grinding time, minutes
1 3 5 7.5 10
+500 14 13 6 3 1
+200 62 34 15 3 1
+160 3 2 1 0 0
+100 5 5 3 1 1
+63 2 4 5 3 2
-63 14 42 70 90 95

Vortex layer devices  intensify the process of obtaining fine-dispersed chalk and receive high quality products. Devices are reliable and can be easily installed in the premises without special foundations. When choosing a particular arrangement (in sequence, parallel, etc.), almost any production line for fine-dispersed chalk could be achieved.

Advantages and disadvantages of disintegrators

Disintegrator is a device that consists of two rotating in different directions rotors, each one is set on a separate shaft or directly on the motor shaft. Disintegrators have high performance, low metal consumption and high energy consumption. However, these disintegrators have  their drawbacks. In particular, there are problems to increasing performance of disintegrators because it overloads the rotors. Also, there is considerable wear of cylindrical fingers which increases proportionally to the speed and the size of processed particles.

The structure of almost any composite material includes a filler. Often it is a component of natural or artificial origin, which is introduced in order to reduce cost and impart desired properties to the final product. Usually, this could be: hardening, reinforcement, sealing, etc. Thus fillers must meet certain requirements, most important of which is the high degree of dispersion.

Most widely used fillers are chalk, dolomite, talc, asbestos, wood flour, kaolin and limestone. In this article we will talk about a finely-dispersed chalk (calcium carbonate). Its area of application covers the production of dry construction mixes, plaster, grout, paper, rubber, plastics, paints and cable products.

Methods of producing chalk

Two methods can be used to obtain chalk. The first is – crushing rocks and sedimentary deposits. The second is – resorting to chemical precipitation. Generally, the particles of natural fillers are larger than the raw material obtained by precipitation.

The form of fine-dispersed chalk particles is determined by the shape of the crystals and the grinding process. In practice, two methods are used for grinding – dry and wet. In wet grinding – the particles obtained are more smooth and round, and cause less wear on the equipment. Therefore, this method is often more preferred..

One of the most popular ways of getting fine-dispersed chalk involves coarse crushing of raw material, magnetic separation, regrinding in a disintegrator, collecting suspension, with the introduction of the dispersant, enriched in hydrocyclones, secondary fine grinding, second suspension collection, controlled screening and spray drying. On completing secondary crushing and collecting of suspension  – it is again washed and dried.

The mere listing of the stages suggests the complexity of this process. Moreover, the finished product obtained by this algorithm does not have very high quality and purity. Therefore, many manufacturers are looking for the opportunity to improve existing processes, to obtain a better product  and  solve waste problems.