WASTE WATER TREATMENT METHOD AND APPARATUS

• Main Authors: NAKABAYASHI AKIRA, HAMAGUCHI TOSHIO, TSUNODA AKIHIKO
• Format: Patent
• Language: English
• Published: 03.12.1996
• Edition: 6
• Subjects: CHEMISTRY; METALLURGY; TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE

PURPOSE: To remove a nitrogen compd. and a phosphorus compd. along with bacteria decomposable org. matter from waste water by replenishing waste water with sludge and mixing the circulating soln. from an aerobic treatment process to anaerobically decompose the same and subjecting a clarified soln. obtained by removing solid matter to aerobic decomposition treatment and removing suspended solid matter from the obtained soln. CONSTITUTION: Waste water to be treated, a phosphorus fixing flocculant and sludge are stirred and mixed in a flocculation and mixing tank 1 to form phosphorus- containing flocs. Subsequently, this flocculated waste water is supplied to an anaerobic tank 2 from the bottom part thereof. At this time, a high polymer flocculant is added to the flocculated waste water on the downstream side of the pump 51 of a flocculated waste water pipe 5 from a polymer flocculant supply pipe 52 to accelerate the growth of phosphorus-containing flocs. A circulating soln. is circulated and supplied to the anaerobic tank 2 by a circulating soln. supply pipe 4 and raised in the tank 2 to be anaerobically decomposed. Solid matter is separated in a solid separation part 22 and the remaining soln. is supplied to the bottom part of an aerobic tank 3 to be aerobically decomposed. A part of the decomposed soln. is circulated by the circulating soln. supply pipe 4 to be used and the remainder thereof is sent to a sand filter 36 to be filtered.