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.