MULTI-ENVIRONMENT WASTEWATER TREATMENT METHOD

摘要

A single-tank wastewater treatment system has a multiplicity of zones with different environmental conditions including aerobic, anoxic and anaerobic, to reduce the strength of highly concentrated wastewaters in terms of their content of organic carbonaceous compounds and nutrients, notably nitrogen and phosphorus. The upper zone of the treatment system operates under alternatively aerobic and anoxic conditions controlled by the on-off operation of an air blower that introduces air through air diffusers placed at the bottom of the upper zone. The lower section of the treatment system contains oxygen-- depleted zones including anoxic conditions at the bottom and anaerobic conditions above the anoxic zones and below the air diffusers. The upper and lower sections of the tank are in fluid communication. Within the volume of upper aerobic zone and lower oxygen-depleted zones, loose carrier material or stationary objects are disposed to support the attachment of microbial biomass and the formation of microbial biofilm. Thus, the treatment system includes both suspended and immobilized microorganisms.