Tag Archives: highly toxic heavy metals

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.

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Natural water resources are becoming a critical problem of today, because of outdated industrial water supply processes, poor state of wastewater treatment plants and old wastewater treatment technologies.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.