Converting small sewage treatment units to fixed bed process - by diverting biomass recirculation pipe to pre-clarification tank, extending aeration below fixed bed installed in aeration chamber

摘要

Small-scale sewage-treatment unit has (a) a pre-clarification tank, (b) an aeration chamber with an aeration supply and acting as an activation tank (10'), and (c) a post-clarification tank (26), which are connected in series, and (d) a pipeline for at least partial recirculation of the biomass deposited in the post-clarification tank or to a separate pipe to lead (36') to the pre-clarification tank or to a separate sedimentation tank or dump, the aeration pipe is extended (18') to the floor of the aeration chamber (10') and is connected to aeration elements (58) running on this floor, and at least one fixed bed or a granular substrate for sessile microorganisms is provided in the aeration chamber (10') above these aeration elements. USE/ADVANTAGE - For upgrading existing small-scale sewage treatment units. Provides a simple means for converting these units from the activation process to the far more effective and less sensitive fixed-bed process