PREVENTION OF SUSPENSION GENERATION IN FINAL SEDIMENTATION POND BY ACTIVATED SLUDGE METHOD

摘要

PURPOSE: To prevent suspension from generating in a final sedimentation pond of a system for treating raw water based on an activated sludge method and thereby enhance the efficiency to separate a solid from a liquid. CONSTITUTION: A suspension generation preventing method consists of a step to realize the sequential inflow of raw water 2 into an aeration tank 3 with several stages and nitrify the water using nitrification bacteria by aerating it from air diffusion pipes 4a, 4b, 4c, 4d, 4e, 4f following the drive of a blower 6, and a step to separate a solid from a liquid in a final redimentation pond and discharge a supernatant liquid as a treated water. In this method, a dissolved oxygen densitometer 8 is installed at the final stage of the aeration tank 3. Further, a dissolved oxygen--densitometer 9 is installed in the final redimentation pond 7, and the drive of the blower 6 is controlled using a controller 10 so that a completely non-oxygen state does not occur in the final redimentation pond 7 based on the readings of dissolved oxygen densitometers 8, 9 and suspension is prevented from generating due to the self-decomposition of sludge, using an activated sludge method.