Modern sewage treatment technology can be divided into three categories based on principles: physical treatment, chemical treatment, and biochemical treatment. Physical treatment method is the use of physical action to separate pollutants in suspended solid state from wastewater. Methods include screening, sedimentation, float flotation, air flotation, filtration, and reverse osmosis. Chemical treatment is the use of chemical reactions to separate and recover pollutants in various forms from wastewater, including suspended, dissolved, and colloidal substances. The main methods include neutralization, coagulation, electrolysis, oxidation-reduction, stripping, extraction, adsorption, ion exchange, and electrodialysis. Biochemical treatment is the use of microbial metabolism to convert dissolved and colloidal organic pollutants in wastewater into stable and harmless substances. The main methods can be divided into two categories, namely aerobic methods utilizing the action of aerobic microorganisms and anaerobic methods utilizing the action of anaerobic microorganisms.
From the above treatment methods, it can be seen that the essence of sewage treatment is to separate and transform pollutants in water, and most of the final products of transformation need to be removed through separation. Therefore, separation is an important part of the sewage treatment process, which directly affects the treatment effect and cost. Obviously, strengthening the separation process is of great significance for improving the level of sewage treatment technology. The use of external magnetic powder to enhance flocculation effect and improve sedimentation efficiency is undoubtedly an effective means of strengthening the separation process. Therefore, the author conducted a preliminary exploration of the formation mechanism and laws of magnetic flocs, and obtained the parameters of magnetic coagulation precipitation process through experiments, thus creating conditions for the application of magnetic coagulation precipitation technology in water treatment.
