What are the methods of laboratory wastewater treatment

There are many kinds of laboratory wastewater below I will say in detail

Redox neutralization and precipitation method

This kind of method is mostly applicable to organic compounds containing hexavalent chromium and toxic substances and metals with reducing properties. It is mainly used to treat wastewater containing cyanide, phenol and sulfide. The common process is to add oxidizing agent to the wastewater, after redox reaction, so that the high toxicity of the material into low toxicity of the material, and then after coagulation, precipitation will be removed from the reaction system. C r6 + and C r3 + inorganic maximum permissible emissions of 0.5 mg / L and 3.0 mg / L. Chromium-containing waste can be used as a reductant of iron, zinc, etc., and the use of waste lye and precipitation, and converted into insoluble salts to be removed. Converted to insoluble salt removed.

2. Sulfide precipitation method

This method is applicable to the acidic experimental wastewater containing mercury, lead and other metals. Generally to the wastewater by adding sodium sulfide, the generation of water insoluble metal sulfide, and then with Fe (OH ) 3 *** precipitation and separation out.

3. Flocculation and precipitation method

Flocculation and precipitation method is not only an effective way to deal with the heavy metals in the sewage of many industrial enterprises, but also a feasible laboratory wastewater treatment

methods. This method is suitable for experimental wastewater containing more heavy metals, adding the appropriate flocculant, under weak alkaline conditions can form a flocculent precipitation, effective removal of heavy metal ions in the wastewater, reduce the wastewater chemical oxygen demand ( COD ).

4. Activated carbon adsorption method

This method is used to deal with physical and chemical methods can not deal with trace amounts of organic experimental wastewater in a dissolved state. Organic experimental wastewater contains a large number of waste solvents, experimental residues, organic acids and so on. Its high concentration and low emissions are very suitable for activated carbon adsorption method. The treatment process is to separate the phase in the wastewater first, and then adsorbed with activated carbon, the removal rate of COD can reach 93%?

5. Incineration method

Each treatment method has its own specific treatment performance, are not universal. Incineration is generally applicable to the formation of emulsions and other liquids. However, special attention should be paid to avoid secondary pollution caused by toxic gases from combustion. For example, for only contains C, H, O elements of organic waste in the combustion generally does not cause secondary pollution, and contains halogen N, S and other elements of organic waste incineration will release a variety of harmful gases.

6. Disposal of biological wastewater?

The common methods used to dispose of biological laboratory wastewater are thermal disinfection and sterilization and chemical disinfection and sterilization. Thermal disinfection sterilization method is through high-temperature heating so that the wastewater temperature reaches or exceeds the maximum limit of the survival temperature of certain harmful microorganisms, killing bacteria to ensure the safety of the discharged wastewater. Chemical disinfection sterilization law is the use of a variety of chemicals in the wastewater of harmful microorganisms for sterilization treatment, the current common disinfection process has ozone disinfection, chlorine disinfection, alkali disinfection and so on. In practice, you can use a combination of thermal and chemical disinfection sterilization, safe and effective treatment of biosafety laboratory wastewater.

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