Method for direct selection of a predetermined low sludge index within an activated sludge method

摘要

In the sewage treatment system, with at least one basin in a biological clarifying stage and a settling tank, a settled and/or settling fraction of sludge with a high index is taken as excess sludge from at least one edge of the settling tank opposite the inflow. The remaining sludge fraction near the inflow, with a low index, is passed to a preceding clarifying stage, and the sludge index is established in at least one basin of the biological clarifying stage. The steps are repeated until a given low sludge index is achieved in at least one biological clarifying basin.