Sewage treatment method capable of realizing advanced nitrogen removal through combined biofilm process

Abstract

The invention relates to a sewage treatment method capable of realizing advanced nitrogen removal through a combined biofilm process. The sewage treatment method comprises the following steps of: connecting an oxygen-limited biofilm reactor and an anoxic biofilm reactor in series; regulating the dissolved oxygen, the sewage retention time and the biological solid retention time in the oxygen-limited biofilm reactor, realizing shortcut nitrification effectiveness, enabling complete nitrification to exist and simultaneously performing nitrification and denitrification for nitrogen removal so as to enable the ratio of ammonia nitrogen to nitrite nitrogen in outlet water of the oxygen-limited biofilm reactor to be close to 1: 1; and regulating the sewage retention time and the biological solid retention time in the anoxic biofilm reactor, and utilizing the adsorption effect of activated carbon against organic matters which are difficult to degrade and the properties of water quality of the outlet water of an oxygen-limited section to realize heterotrophic denitrification for nitrogen removal and anaerobic ammonium oxidation for nitrogen removal. Compared with the prior art, according to the sewage treatment method disclosed by the invention, through the oxygen-limited and anoxic combined biofilm treatment process, the reinforced shortcut nitrification of the oxygen-limited section is realized, the heterotrophic and autotrophic simultaneous nitrogen removal effectiveness of an anoxic section is realized, and the advanced nitrogen removal effect against sewage with low concentration of organic matters and low carbon-nitrogen ratio can be achieved.

Description

technical field [0001] The invention relates to a sewage advanced treatment method, in particular to a sewage treatment method for deep denitrification through a combined biofilm process. Background technique [0002] At present, for the denitrification treatment of sewage with low organic carbon source content, the suspended activated sludge method is still the main process. Due to the low organic matter load, the sludge has low activity and is easy to disintegrate. In practice, physical and chemical flocculation measures are often used to strengthen the stability of activated sludge flocs, but it often increases the content of organic polymer substances in sludge and increases the difficulty of disposal of excess sludge. [0003] In order to avoid the shortcomings of the suspended activated sludge process, the application of biofilm treatment technology is becoming more and more extensive. At present, in the biofilm reaction tank directly used in the sewage biological tre...

AI Technical Summary

Problems solved by technology

For sewage with a low carbon-to-nitrogen ratio, especially for most urban sewage in southern my country where COD / TKN<5.0, the efficiency of traditional biological nitrogen removal is often limited due to insufficient organic carbon sources

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