Wastewater treatment process for the production of superhard materials
With the continuous progress of science and technology, superhard materials are more and more widely used in the industrial field, but the impact of wastewater generated in the production process on the environment has also attracted increasing attention. Superhard material production wastewater has the characteristics of high hardness, high salinity, high ammonia nitrogen, etc., and it is difficult to treat. In order to solve this problem, this article will focus on the treatment process of wastewater from the production of superhard materials.
First, the characteristics of wastewater.
The wastewater from the production of superhard materials mainly includes the wastewater generated by cutting, grinding, polishing and other processes. These effluents have the following characteristics:
1.High content of suspended solids, the main components include abrasive particles, polymers, etc.;
2.The content of COD (chemical oxygen demand) and BOD (biological oxygen demand) is high, mainly in the decomposition products of organic solvents and additives in the processing process;
3.Contains a large number of inorganic salt ions, such as Ca2+, Mg2+, Cl-, etc.;
4.The ammonia nitrogen content is high, mainly due to the decomposition products of surfactants and organic nitrogen compounds used in the processing process.
Second, the treatment process.
According to the characteristics of superhard material production wastewater, the following treatment processes can be adopted:
1.Pretreatment.
The purpose of pretreatment is to remove large particles of suspended solids and oily substances from the wastewater and create favorable conditions for subsequent treatment. Commonly used pretreatment methods include: sedimentation, filtration, degreasing, etc.
2.Chemical precipitation.
The chemical precipitation method is to add chemicals to the wastewater to convert the inorganic salts with low solubility into precipitate, and then remove them by solid-liquid separation. Commonly used chemicals include: lime, sulfuric acid, etc. This method can effectively remove Ca2+, Mg2+, Cl- and other ions in wastewater.
3.Biological treatment.
The biological treatment method converts the organic matter in the wastewater into harmless substances through the metabolic action of microorganisms. Commonly used biological treatment methods include: activated sludge method, biofilm method, etc. This method can effectively remove COD and BOD from wastewater. In the process of biological treatment, it is necessary to select appropriate microbial strains according to the actual situation of wastewater, and control environmental factors such as temperature and pH.
4.Advanced oxidation.
Advanced oxidation is the conversion of organic matter into harmless substances through strong oxidants. Commonly used advanced oxidation methods include: ozone oxidation, Fenton reagent oxidation, etc. This method can effectively remove refractory organic matter from wastewater. In the advanced oxidation process, it is necessary to control the dosage of oxidant to avoid secondary pollution.
5.Membrane separation.
Membrane separation is the separation and purification of substances in wastewater through membrane filtration technology. Commonly used membrane separation methods include: ultrafiltration, nanofiltration, reverse osmosis, etc. This method can effectively remove salts and harmful substances from wastewater. During the membrane separation process, the membrane module needs to be cleaned and maintained regularly to ensure its normal operation.
Third, the process flow.
According to the characteristics of superhard material production wastewater, the following process can be used for treatment:
1.Pretreatment stage: removal of suspended solids and oily substances in wastewater by sedimentation, filtration and other methods;
2.Chemical precipitation stage: Ca2+, Mg2+, Cl- and other ions in wastewater are removed by adding chemical agents;
3.Biological treatment stage: removal of COD and BOD in wastewater by activated sludge method or biofilm method;
Wastewater treatment