What is industrial wastewater?
According to the classification of sewage sources, sewage treatment is generally divided into production sewage treatment and domestic sewage treatment. Production wastewater includes industrial sewage, agricultural sewage, and medical sewage, and domestic sewage is sewage generated by daily life. Sewage treatment is widely used in construction, transportation, energy, petrochemical, environmental protection, urban landscape, medical, catering and other fields, and more and more into the daily lives of ordinary people.
Processing degree division
Modern sewage treatment technologies can be divided into primary, secondary and tertiary treatments according to the degree of treatment.
It mainly removes the solid pollutants in the suspended state in the sewage, and most of the physical treatment methods can only fulfill the requirements of the primary treatment. After the primary treatment of sewage, BOD can generally be removed by about 30%, failing to meet emission standards. Primary treatment is a pretreatment of secondary treatment.
It mainly removes organic pollutants (BOD, COD substances) in colloid and dissolved state in sewage, and the removal rate can reach more than 90%, so that organic pollutants can reach the discharge standard.
It further processes refractory organic matter, soluble inorganic substances such as nitrogen and phosphorus, which can cause eutrophication of water bodies. The main methods include biological nitrogen and phosphorus removal methods, coagulation sedimentation method, sand ratio method, activated carbon adsorption method, ion exchange method and electroosmosis analysis method.