METHOD AND PLANT FOR BIOLOGICAL TREATMENT OF WASTE WATERS Russian patent published in 1998 - IPC

FIELD: waste water treatment. SUBSTANCE: invention relates to treating waste water by biological activation technique wherein waste water is biologically purified in the course of activation process involving nitrification. Activating mixture is introduced into piston flow-mode circuit while treated water is withdrawn from the circuit and activating mixture is mixed with waste water after treated water is withdrawn. The latter leads to oxygen deficiency on the surface of activated sludge particles initiating denitrification processes. Resultant mixture is aerated to maintain activated sludge in suspended state. As piston flow progresses, mixture is gradually saturated by oxygen. Plant always has two separation spaces 4 adjoining to each other over their longitudinal sides. In the latter, passages are formed to communicate with activation space. There is also longitudinal distribution canal 5 formed by indicated side walls and completely closed by end wall on one side, whereas, on the opposite end, a passage is remained through which distribution canal communicates with pressure canal system 7. EFFECT: intensified treatment. 28 cl, 13 dwg