A/O biofilm denitrification device and method for treating low c/n sewage

Abstract

The invention discloses an A / O bio-membrane denitrifying device and method for treating low-C / N sewage. The device comprises a raw water tank, a water inlet pump, an A-section bio-membrane reactor, an O-section bio-membrane reactor, a nitrifying liquid internal reflux pump. The raw water tank is a closed box and is provided with an overflow pipe and a blow-down pipe; the A-section bio-membrane reactor is shaped like a column and is divided into an upper section and a lower section according to the water flow direction, the lower section adopts a short-cut denitrification bio-membrane, and the upper section adopts an anaerobic ammonia oxidation bio-membrane; the O-section bio-membrane reactor is shaped like a column and is filled with a nitrifying bio-membrane. According to the denitrifying method, short-cut denitrification is achieved through the lower section of the A-section bio-membrane reactor, organic carbon sources in the sewage are utilized, and nitrate nitrogen carried by reflux nitrifying liquid is reduced to nitrite nitrogen; anaerobic ammonia oxidation is achieved through the upper section bio-membrane, and partial ammonia nitrogen in the sewage and nitrite nitrogen accumulated through short-cut denitrification are converted into nitrogen; residual ammonia nitrogen in the sewage is oxidized into nitrate nitrogen through the O-section bio-membrane reactor, and efficient nitrogen removal of the low-C / N sewage is achieved.

Description

technical field [0001] The invention relates to an A / O biofilm denitrification device and method for treating low C / N sewage, and belongs to the technical field of sewage biological treatment. Background technique [0002] At present, the biological denitrification of sewage mostly adopts the traditional biological nitrification and denitrification denitrification technology, and the denitrification process requires organic carbon sources as electron donors to reduce nitrogen oxides to nitrogen. Therefore, low C / N sewage containing insufficient organic carbon sources is difficult to efficiently denitrify. In order to meet the discharge standards, it is necessary to add external carbon sources to improve the denitrification effect, thereby increasing the cost of sewage treatment. [0003] The traditional biological denitrification process is to gradually reduce nitrate nitrogen to nitrogen through the action of nitrate nitrogen reductase, nitrite nitrogen reductase, nitric ox...

AI Technical Summary

Problems solved by technology

The latest research shows that some denitrifying bacteria can only secrete nitrate nitrogen reductase, so that the reduction rate of nitrite nitrogen is lower than that of nitrite nitrogen, resulting in the accumulation of nitrite nitrogen in the denitrification process, that is, short-term Denitrification phenomenon

Images