摘要 |
In the biological purification of wastewater containing organic impurites, wherein the wastewater is passed through a reaction (1), e.g., continuous flow-stirred tank having circulating means (12) to achieve thorough mixing therein, or a fluidized bed or suspended bed type reactor, the wastewater is aerated in the presence of activated sludge with an oxygen containing gas fed through a gas feed conduit (9), and in a post clarification stage (5), the wastewater-activated sludge mixture from the reactor (1) is separated into purified water and sludge, the improvement comprises conducting the biological purification in the reactor (1) in the presence of a carrier material for microorganisms. The carrier material comprises particles of macroporous material having a low specific gravity, and in piece and/or granulated form in an amount such that the suspended individual particles are freely movable in the wastewater. Soft polyurethane foam particles are especially preferred as the carrier materail. In addition, a predetermined free activated sludge is maintained in the reactor.
|