METHOD FOR EFFECTIVE UTILIZATION OF EXCESS SUPERNATANT BY ACCOMPANYING HIGHLY HYDROUS SLUDGE TREATMENT USING HIGH MOLECULAR COAGULANT

摘要

PROBLEM TO BE SOLVED: To effectively utilizing excess supernatant produced by utilization of a high molecular coagulant in performing highly hydrous sludge treatment by utilizing the high molecular coagulant. SOLUTION: The excess supernatant produced in a pretreating process step for the highly hydrous sludge using the coagulant is effectively utilized as an aqueous hexad chromium reducing solution which is mainly composed of a strong acid salt and is added with a reducing agent or as an aqueous coagulation effect promoting solution which is mainly composed of a light metal and is added with a chloride.