| 摘要 |
A process for treating effluent such as untreated biological effluent includes a primary clarifier (1) where sludge solids are settled out from a liquid sludge fraction. The sludge solids pass to a digester (2) where the sludge solids undergo anaerobic digestion to produce digested sludge and biogas. The digested sludge is dewatered and the liquid sludge fraction and the liquid component of the dewatered digested sludge is passed to an activated sludge tank (6). The resulting activated sludge solids are then concentrated by settlement, dewatered, and flocculated under alkaline and acidic conditions. The resultant acidic activated sludge solids are neutralized before and passed to a mixing and drying apparatus (5) where the solids are mixed with the digested sludge and dried using the bio-gas as a fuel. <IMAGE> |
