Method for realizing shortcut nitrification and denitrification nitrogen removal by oxidation ditch segmental water-feeding process

Abstract

Belonging to the field of biological sewage treatment, the invention relates to a method for realizing shortcut nitrification and denitrification nitrogen removal by oxidation ditch segmental water-feeding process. The method includes that: urban sewage is divided into four equal parts to enter an anoxic zone of an oxidation ditch reactor, denitrifying bacteria utilize organic matters in the sewage as the carbon source to reduce nitrite nitrogen produced by a previous aerobic section into nitrogen, then the sewage enters an aerobic zone, and ammonia oxidizing bacteria oxidize ammonia nitrogen into nitrite nitrogen; then the sewage enters an anoxic zone and an aerobic zone in order; part of precipitated sludge in a secondary sedimentation tank enters a sludge treatment zone, free ammonia is employed to treat the sludge, and then the sludge flows back to the oxidation ditch anoxic zone; selective inhibition is carried out on nitrite oxidizing bacteria in the sludge by free ammonia so as to control the increase of nitrite oxidizing bacteria in the sludge and maintain shortcut nitrification in the oxidation ditch process; and finally shortcut nitrification and denitrification nitrogen removal of urban sewage can be realized, the nitrogen removal effect is improved, and the treatment energy consumption is reduced.

Description

technical field [0001] The invention relates to a method for realizing short-range nitrification and denitrification through an oxidation ditch staged water inlet process, which belongs to the technical field of sewage biological treatment. Background technique [0002] The removal of nitrogen pollutants in urban sewage plays an important role in the control of water eutrophication. At present, most sewage treatment adopts the traditional nitrification and denitrification biological denitrification process. The principle of this process is to convert ammonia nitrogen into nitrate nitrogen through the action of ammonia oxidizing bacteria under aerobic conditions, and then convert nitrate nitrogen to nitrate nitrogen through organic matter in the anoxic area. It is reduced to nitrogen, so as to achieve the purpose of removing nitrogen in sewage. [0003] Short-range biological denitrification is a new type of sewage treatment technology. Its basic principle is to control the ...

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Problems solved by technology

[0005] The purpose of the present invention is to solve the problem that it is difficult to control the growth of nitrite oxidizing bacteria in the existing urban sewage treatment. Based on the selective inhibition of nitrite oxidizing bacteria, a staged water inlet process of oxidation ditch is proposed to realize short-range nitrification and denitrification denitrification The method, the method first is that urban domestic sewage is divided into four equal parts and enters the anoxic zone of the oxidation ditch reactor, and the denitrifying bacteria use the original organic matter in the sewage as a carbon source to convert the nitrite nitrogen produced in the previous aerobic section It is reduced to nitrogen, and then enters the aerobic zone, where the ammonia oxidizing bacteria oxidize ammonia nitrogen to nitrite nitrogen; then passes through the anoxic zone and the aerobic zone in turn; part of the sedimented sludge in the secondary sedimentation tank enters the sludge treatment zone, and is treated with free ammonia After that, it flows back to the anoxic zone of the oxidation ditch; the free ammonia selectively inhibits the nitrite oxidizing bacteria in the sludge, controls the growth of the nitrite oxidizing bacteria in the sludge, and maintains short-range nitrification in the oxidation ditch reactor; finally realizes urban Short-cut nitrification and denitrification of sewage to improve denitrification effect and reduce treatment energy consumption

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