METHOD FOR RECOVERING PHOSPHORUS COMPONENT IN SLUDGE AND APPARATUS THEREFOR

摘要

PROBLEM TO BE SOLVED: To prevent the clogging of a sewage sludge transport pipe to enhance sludge treatment efficiency. SOLUTION: Sludge generated in a sewage disposal plant is treated under an anaerobic atmosphere to discharge a phosphorus component in sludge. This sludge is separated into concentrated sludge and a concentrated separated liquid. The concentrated sludge is dehydrated to be separated into dehydrated sludge and a dehydrated separated liquid. The phosphorus component in the dehydrated separated liquid and the concentrated separated liquid is recovered by a dephosphorizing material. Before excess sludge or mixed sludge of excess sludge and raw sludge is digested in a digestion tank, the concentration of the phosphorus component in sludge is lowered. The formation of crystals of ammonium magnesium phosphate in the transport pipe of digested sludge can be prevented. The phosphorus component is discharged from activated sludge in a short time without digesting excess sludge or mixed sludge. The surface of a discharge tank can be reduced and existing equipment can be also easily increased. COPYRIGHT: (C)2003,JPO