Recovery and reuse of phosphorus and flocculant in wastewater

摘要

PROBLEM TO BE SOLVED: To recover and recycle phosphorus and flocculating agents in insolubilizing the phosphorus included in waste water by addition of the flocculating agents and settling and removing the same by a countermeasure for eutrophication in industrial waste water treatment or the like. SOLUTION: The waste water containing the phosphorus is admitted into a bioreaction chamber 10 where the inorganic flocculating agents of an aluminum system are added thereto. The flocculated and settled sludge formed by the insolutilization of the phosphorus in the liquid is subjected to alkaline treatment within a phosphorus and flocculating agent component elution vessel 13 and is subjected to separation 14 of solid from the liquid by eluting the phosphorus and the flocculating agent components into the liquid. The phosphorus is recovered from the separated liquid containing the phosphorus and the flocculating agent components by adding chemicals of a calcium base to insolubilize the phosphorus. On the other hand, the separated liquid in which the flocculating agent components after the phosphorus recovery remain is added into an aerator in a waste water or biological treating process step or is added to the return flow water discharged from the sludge treating process step of a waste water treatment facility, by which the phosphorus in the liquid is removed.