Views: 31 Author: Site Editor Publish Time: 2021-05-11 Origin: Site
Modern wastewater treatment technology can be divided into primary treatment, secondary treatment and tertiary treatment according to the degree of treatment. In general, the degree of wastewater treatment equipment can be determined by the water quality and the flow of treated water, and different valves are used for each level.
Primary treatment mainly removes suspended solid pollutants, and most physical treatment methods can only meet the requirements of primary treatment. After primary treatment, the BOD removal rate is generally around 30%, which does not meet the discharge standard. The primary treatment belongs to the pre-treatment of secondary treatment. Valves and their piping accessories include: knife gate valves, triple eccentric butterfly valves, filters, etc.
Secondary treatment is mainly used to remove colloid and dissolved organic pollutants (BOD, COD) in the sewage, with removal rate of more than 90%, so that organic pollutants meet the discharge standard and the removal rate of suspended matter reaches 95%. The valves used are soft seal butterfly valve, gate valve, ball valve and check valve.
Further treatment of tertiary treatment of hard-to-degrade organic matter, nitrogen and phosphorus can lead to eutrophication of soluble inorganic matter in the water. The main methods are biological denitrification and phosphorus removal, coagulation and sedimentation, sand filtration, activated carbon adsorption, ion exchange and electrodialysis. The valves used include butterfly valves, gate valves, ball valves, check valves and rubber flexible joints.
