PRESSURIZED AERATION TANK FOR ACTIVATED-SLUDGE PROCESS SEWAGE TREATMENT

摘要

A pressurized aeration tank is provided which comprises an inner barrel arranged on the tank axis and an axial-flow impeller of optimum characteristics mounted therein, the inner barrel and the outer barrel or body portion of the tank being particularly proportioned and arranged relative to each other to define in the tank a circuitous flow passage of minimal total resistance loss. With this tank structure, a highly improved plant efficiency of BOD removal is readily obtainable with the use of concentrated activated sludge and aerobic microorganisms, mainly of the Opercularia group, in a specified range of tank pressure.