METHOD AND APPARATUS FOR ORGANIC WASTEWATER TREATMENT CAPABLE OF PREVENTING DECREASE IN PERMEATION EFFICIENCY OF SUBMERGED MEMBRANE WITHOUT DILUTION

摘要

A method and apparatus for wastewater treatment is provided which can prevent any decrease in permeation efficiency of a submerged membrane without involving an increase in operating cost and sludge generation, and which can treat high concentration organic wastewater efficiently and without dilution. The wastewater treatment method has the steps of: concentrating domestic sludge by means of a first submerged membrane to produce thick sludge; mixing the thick sludge into a water to be treated, and introducing the water to be treated which is so mixed with the thick sludge into an anaerobic treatment portion for anaerobically treating the same; and introducing the anaerobically treated water from the anaerobic treatment portion into an aerobic treatment portion having a second submerged membrane disposed therein to subject the water to aerobic treatment. The water to be treated undergoes treatment with the thick sludge through which its dissolved oxygen content is reduced to zero and organic substances contained therein are adsorbed by the sludge for subsequent treatment in the anaerobic treatment portion.