Main chemical industrial wastewater from oil chemical industry, coal chemical industry, acid and alkali, chemical fertilizer industry, plastic industry, pharmaceutical industry, dye production wastewater from industry, rubber industry, etc.
The main measures for the prevention and control of chemical waste water pollution are as follows: first of all, the production process and equipment should be reformed to reduce pollutants, prevent the effluent from being discharged out, and carry out comprehensive utilization and recovery.
The degree of treatment of effluent that must be discharged shall be selected according to the water quality and requirements.
Primary treatment of suspended solids, colloids, floating oil or heavy oil in water.
Water quality can be adjusted, natural precipitation, floating and oil separation methods.
Secondary treatment is mainly to remove the biodegradable organic solvents and some colloids, and reduce the biochemical oxygen demand and partial chemical oxygen demand in the wastewater. Biological treatment is usually adopted.
After biological treatment of wastewater, is still a considerable amount of COD, sometimes have higher color, smell, taste, or because of high environmental health standards, tertiary treatment methods is needed to further purification.
The tertiary treatment is mainly to remove organic pollutants and soluble inorganic pollutants which are difficult to biodegrade in wastewater.
The commonly used methods are activated carbon adsorption and ozone oxidation, ion exchange and membrane separation.
Various chemical industrial wastewater can be treated by different treatment methods according to different water quality, water quantity and the requirement of effluent water after treatment.