A sewage treatment method and device with both deep nitrogen and phosphorus removal and mud-water gravity separation

Abstract

The invention discloses a sewage treatment method and a sewage treatment device integrating deep nitrogen and phosphorous removing and sludge-water gravitational separation. The sewage treatment device comprises a stirring pond I, a stirring pond II, an aeration / stirring alternating pond, an oxygenating pond and a sludge-water gravitational separation device. The sewage treatment method for completing the deep nitrogen and phosphorous removing comprises the steps of firstly, enabling sewage to enter the stirring pond I to complete a hydrolyzing and phosphorous releasing process; secondly, enabling the sewage to enter the stirring pond II to complete nitrogen removal by denitrification; thirdly, enabling the sewage to enter the aeration / stirring alternating pond to complete a nitration reaction and dephosphorization by adsorption; finally, enabling the sewage to enter the oxygenating pond and the sludge-water gravitational separation device to further remove BOD (Biochemical Oxygen Demand), ammonia nitrogen and total phosphorous and complete the sludge-water gravitational separation. According to the sewage treatment method and the sewage treatment device integrating the deep nitrogen and phosphorous removing and the sludge-water gravitational separation, disclosed by the invention, dual anaerobic-anoxic-aerobic cycling is created, not only are advantages of a traditional nitrogen and phosphorous removing technology exerted, but also the bottlenecks of a traditional technology that backflow of a digestive solution is incomplete and organic matters are insufficiently utilized are completely solved, the efficiency of removing nitrogen and phosphorous in the sewage can be increased from 50 to 70 percent to 90 percent or more than 90 percent, and the content of the total nitrogen and the total phosphorous in outlet water can be respectively reduced to 3mg / L and 0.4mg / L when conventional municipal sewage is treated.

Description

technical field [0001] The present invention relates to a sewage treatment method and device, more specifically, to a sewage treatment method and device capable of deep denitrification and phosphorus removal and gravity separation of mud and water. Background technique [0002] Nitrogen and phosphorus are key pollutants that lead to eutrophication of water bodies, and are much more difficult to remove than COD and TSS. According to my country's "Pollutant Discharge Standards for Urban Sewage Treatment Plants" (GB 18918-2002) Class A standard, the effluent ammonia nitrogen, total nitrogen and total phosphorus should be less than 5, 15 and 0.5 mg / L respectively. However, my country's "Surface Water Environmental Quality Standards" (GB 3838-2002) stipulates that ammonia nitrogen, total nitrogen and total phosphorus in Class V water environment should be less than 2.0, 2.0 and 0.4 mg / L respectively. This means that even if the effluent of urban sewage treatment plants reaches t...

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Problems solved by technology

[0005] Based on the above reasons, there is an urgent need for a low-cost, high-efficiency deep nitrogen and phosphorus removal process and a gravity flow membrane separation device, which can not only take advantage of the small footprint of the membrane bioreactor while completing the deep nitrogen and phosphorus removal It has the advantages of high load and low sludge output, and can overcome the disadvantages of easy membrane fouling, complicated operation and high energy consumption.

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