TREATMENT OF SLUDGE WASTE WATER AND WATER PURIFIER

PROBLEM TO BE SOLVED: To provide an economical sludge waste water treating method by which the settled sludge drawn off from a settling basin and the waste washing water discharged from a filter basin are always concentrated to a stabilized sludge concn. throughout the year, the quality of the supernatant water to be returned to a water well is improved, and the chlorine-resistant pathogenic microorganisms, etc., are not circulated in the water purifying system and to furnish a water purifier. SOLUTION: The raw water taken in from rivers, etc., is flocculated, settled and filtered as follows. Namely, the sludge settled on the bottom of a settling basin 4 is supplied to a membrane concentrator 7 and treated with a membrane. The sludge concentrated to 5-10% solid content is introduced into a dehydrator 8, and the waste backwashing water discharged from a filter basin 5 is supplied to a membrane filter 10 and treated with a membrane.