METHOD AND APPARATUS FOR SURPLUS SLUDGE TREATMENT

摘要

An excess sludge treatment method that can realize a large volume reduction of excess sludge by efficiently treating excess sludge generated from an activated sludge aeration tank even without extension of the concerned aeration tank, blowers and use of ozone in an activated sludge treatment process of various organic wastewater is provided. A method of treating excess comprises the processes of; extracting an excess sludge from an activated sludge tank or a sludge sedimentation tank and injecting the excess sludge into a hypochlorous acid treating tank through an injection port; treating a portion or all of the excess sludge by mixing a weak acidic hypochlorous acid-containing aqueous solution with the excess sludge at a mixing ratio of 500 to 20,000 ppm as an effective chlorine concentration converted relative to the excess sludge; and discharging out or returning to the activated sludge tank the activated sludge with a degree of substantially inert residual chlorine concentration.