Process for enhancing denitrogenation of membrane bioreactor by anaerobic fermentation acid production

Abstract

The invention relates to a process for enhancing denitrogenation of a membrane bioreactor by anaerobic fermentation acid production. The process adopts an enhanced anaerobic tank, an anoxic tank and an aerobic tank. After entering the process, the sewage undergoes biochemical treatments including anaerobic fermentation, anaerobic denitrification and aerobic nitrification under the action of different kinds of microorganisms, and finally the effluent is sucked and collected by membrane filtration. By optimizing the growth environment of microorganisms in the anaerobic section, the process, on the one hand, promotes hydrolysis acidification of particle-stage organic matters (including colloid-state organic matters), slowly-degradable organic matters and hardly-degradable organic matters in the raw sewage, and on the other hand, produces acids from the excessive activated sludge which is discharged to the anaerobic tank to provide high-quality carbon sources for anaerobic denitrification. Besides, the process enhances the biological denitrification process by increasing sludge concentration, solves the problem of insufficient carbon source in biological denitrification process, and achieves the purpose of removing total nitrogen from the sewage with high efficiency by virtue of high-efficiency cut-off and separation characteristics of the membrane. The process can supplement carbon sources to the denitrification section for enhanced denitrogenation by fully utilizing converted carbon sources in the incoming water and carbon sources generated by sludge fermentation in the process without needing extra carbon sources. The process is simple and flexible in control, and the total nitrogen in the effluent can reach or exceed the first-class (A-class) discharge standard.

Description

technical field [0001] The invention belongs to the technical field of water and waste water treatment, and in particular relates to an anaerobic fermentation acid production enhanced membrane-bioreactor denitrification treatment process. Background technique [0002] With the increasing pollution of environmental water bodies, many countries and localities have formulated stricter nutrient discharge standards to prevent further eutrophication of receiving water bodies. At present, more and more places in my country require the effluent of urban sewage plants to meet the first-level A standard of the "Pollutant Discharge Standards for Urban Sewage Treatment Plants" (GB18918-2002), in which the total nitrogen requirement is <15mg / L; while the Beijing area has formulated a comprehensive The transformation technology to improve the effluent quality of sewage treatment plants requires that the treated effluent meet the surface water level IV water body standard, in which the t...

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Problems solved by technology

[0005] The traditional biological denitrification process usually uses pre-denitrification or post-denitrification to remove nitrogen. The AAO process with anaerobic section can realize denitrification and phosphorus removal simultaneously. Among them, the denitrification process is mainly in the anoxic The nitrate nitrogen and nitrite nitrogen produced by the nitrification in the aerobic stage flow back to the anoxic stage for denitrification; however, after the sewage passes through the anaerobic stage, a large amount of easily biodegradable organic matter in the sewage is destroyed removal, resulting in insufficient carbon source in the anoxic section, and the denitrification process is inhibited, which affects the denitrification effect

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