Process for the biochemical purification of waste water containing organic constituents which favour the undesirable development of filamentous bacteria and/or the formation of bulking sludge

摘要

The organic constituents are degraded in a first activation tank (11) under aerobic growth conditions to the extent that both in this stage and in a second activation tank (21) under aerobic growth conditions, dominant formation of filamentous bacteria and bulking sludge is prevented. The pH of the waste water is initially adjusted so that the waste water has a pH of at least 6 on leaving this first biochemical stage (10). The waste water in the activation tank (11) is then aerated with air or oxygen until the organic compounds which favour the uncontrollable growth of filamentous bacteria are largely degraded. The concentration of the dissolved oxygen in the activation tank (11) must be kept at least high enough so that the concentration of the dissolved oxygen is still measurable in the overflow to the second biochemical stage (20). The activated sludge flocks forming in the first biochemical stage (10) are continuously separated off. In the activation tank (11) a biochemical unit per unit volume as high as possible is maintained. IMAGE