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The subjects of A / O membrane bioreactor for municipal wastewater treatment, the effects of the treatment effect and operating conditions of the reactor, and focusing on the process parameters on nitrogen removal effect in denitrification membrane bioreactor aspects of the application of the theoretical and practical basis. The experimental results show that: A / O membrane bioreactor system turbidity removal, effluent turbidity stabilized at about 1NTU. A / O membrane bioreactor 85.33% average removal rate of CODcr effluent basically stable at 38.9mg / L, a strong resistance to shock loading. The ideal membrane bioreactor removal of ammonia the basic effluent ammonia concentration can be maintained below 1mg / L, the film itself ammonia removal contribute little, but a large number of denitrifying bacteria can be enriched in the reactor through the membrane Interception , play an enhanced role for the removal of ammonia. System of total nitrogen removal is very unstable. In the gas-water ratio were 30:1,40:1 and 50:1, investigated the removal of ammonia nitrogen and total nitrogen, the results show that the gas-water ratio from 30:1 to 40:1, conducive to the removal of ammonia, to continue to improve the gas-water ratio, no significant increase in ammonia nitrogen removal. With the increase in the ratio of gas-water system average total nitrogen removal rate, showing a downward trend. So in actual operation, considering the total nitrogen and ammonia removal, select a suitable gas-water ratio. Reflux ratio of ammonia nitrogen and total nitrogen removal effect that: reflux ratio of 230%, 200% and 100%, reflux is less than the removal of ammonia nitrogen in the gas-water ratio of 40:1, analysis, The average removal rates were 99.6%, 99.2% and 98.3%, respectively, at a reflux ratio of 230%, the removal of ammonia is the most stable. Decreasing reflux ratio, the average of the membrane bioreactor total nitrogen removal decreases after the first increase, and therefore considering 200% of the reflux ratio is more suitable for the actual run. In the early running, with increasing sludge concentration, ammonia nitrogen and total nitrogen removal have increased sludge concentration of 4500mg / L, ammonia nitrogen removal enhanced stability, the removal rate is no longer with the sludge concentration. Sludge concentration changes around 6000mg / L, total nitrogen removal of the relatively good results, the higher the concentration of the sludge not guarantee higher TN removal and sludge aging, reduce the total Nitrogen removal efficiency and stability. The experimental determination of a segment of the activated sludge in the aerobic reactor than the rate of nitrification, compared with the pure culture of the nitrifying bacteria, than the rate of nitrification of the system to be smaller by an order of magnitude. To anoxic mixture after dosing organic carbon source, denitrification rate accelerated more thorough denitrification, the removal efficiency of the carbon source to improve the system by dosing.
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