METHOD FOR BIOLOGICAL TREATMENT OF WASTE WATERS Russian patent published in 2001 - IPC

FIELD: waste water treatment. SUBSTANCE: invention relates to biomechanical treatment of waste waters and is designed for use on industrial and municipal treatment plants. Method involves continuous treatment of waste water in precipitation mode accompanied by separation of dispersed pollutions, aerobic biological treatment of waste water when in mixture with active sludge followed by separation and circulation of separated biomass of activated sludge and subsequent postpurification of clarified waste water. Processes of precipitation and separation of dispersed pollutions and biomass of activated sludge are carried out simultaneously and combined in the same settling clarifier by way of filtering waste water through suspended activated sludge bed. In that case, accumulated sludge-pollution mix is withdrawn into flow circuit. Within this circuit, aerobic biological treatment of sludge- pollution mix in high-duty air tank is carried out to reuse pollution fraction and stabilize activated sludge. Thus formed watersludge mix is mixed with fresh waste water fed into settling clarifier, whereas another portion of fresh waste water is supplied into high-duty air tank without any preliminary treatment. Water-sludge mix resulting from aerobic treatment is subjected to additional physico-mechanical treatment and mix obtained this way, prior to be directed to settling clarifier, is mixed with fresh waste water in specially designed preaerator. Sludgepollution mix discharged from settling clarifier, prior to by supplied into high-duty air tank, is preliminarily diluted with fresh waste water. EFFECT: enhanced process efficiency, in particular reduced volume of equipment, increased reliability of process, and increased resistance of microorganisms of activated sludge under unfavorable medium effects. 6 cl, 6 dwg, 1 tbl _