METHOD AND APPARATUS FOR TREATING EXCESSIVE SLUDGE

• Main Authors: MORI SHOICHI, TAKAHASHI SHIGEKAZU, KUWABARA HIDEYUKI, KAZUMA KENJI, TSUCHIDA TOMOHIKO
• Format: Patent
• Language: English
• Published: 13.02.1996
• Edition: 6
• Subjects: CHEMISTRY; METALLURGY; TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE

PURPOSE:To reduce a generation amt. of excessive sludge by digesting and decomposing excessive sludge conc. and separated in the rear stage of a waste water treatment method using bacteria by utilizing a food-chain of a protozoan or metazoan in a multistage digestion tank packed with a bacteria carrier. CONSTITUTION:At first, raw waste water is sent to a first sedimentation basin 1 and a precipitate such as metals or salts and activated sludge in raw waste water are sent to a sludge treatment process 4. The mixed soln. of waste water and activated sludge in the first sedimentation basin 1 is sent to an aeration tank 2 to be aerated by air and subjected to decomposed treatment by bacteria to be sent to a final sedimentation basin 3. Supernatant water in the final sedimentation basin 3 is discharged as purified water and a part of excessive activated sludge is returned to the first sedimentation basin 1 to be utilized as seed bacteria. Excessive sludge is digested in an excessive sludge digestion tank 5 to change org. matter to CO2 or H2O by a food-chain of a protozoan or metazoan to be reduced in vol. and the treated water is again returned to the first sedimentation basin 1.