A New Activated Sludge Process without Excess-sludge Production.

A new activated sludge process which produces no excess-sludge has been developed and applied to the waste water of paper mills. This new process (named “BIOLEADER® ”) is composed of sludge ozonation stage and biological treatment stage. Ozone treatment enhances biological degradation of activated sludge. The important conditions to eliminate excess-sludge are the amount of the ozonation sludge which return to aeration tank and pH condition to minimize ozone dose.It was verified that the application of “ BIOLEADER® ” to waste water of paper mill comparing with a conventional activated sludge treatment is valid. The process has been eliminating excess-sludge almost completely. The effluent water quality indicated almost the same level as that of a conventional activated sludge treatment.