Compact sewage purification plant

摘要

The plant comprises two concentric tubes. Sewage is received into an aerated suspension of aerobic biological sludge which may be mixed with circulating sand particles, or circulating through static plastic media, around the annulus. The solids are maintained in suspension by a ring shaped diffuser and the circulation sustained by an air lift. Effluent and sludge pass to the inner tube for settlement and clarified effluent is removed by airlift which buffers hydraulic fluctuations by permitting variable operating levels. The sand particles or plastic media provide support to accommodate high biomass concentrations to reduce the volume of the aeration annulus. A constantly recycled flow from the settlement tube improves the quality of the cesspit liquor.