Tag Archives: Wastewater Treatment

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!

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



Maximum concentration level (European Union legislation)

Before treatment

After treatment







Fe, mg/l





Cu, mg/l





Ni, mg/l


<0,02 (not detected)



Cr+6, mg/l


<0,005 (not detected)


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.

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.

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.

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.

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.

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.