The Constrast Experiment Between Facultative And Aerobic Membrane Bioreactor Treatment Of Low Carbon And Nitrogen Ratio Sewage

With the improvement of people’s living standard, the ammonia nitrogen content of sewage is higher and higher. It result in the low carbon and nitrogen ratio in urban sewage and disadvantage of the treatment of nitrogen removal. Therefore, wastewater ammonia nitrogen removal technology research attract more and more attention. The project of facultative and aerobic membrane bioreactor under the condition of different carbon nitrogen ratio of treatment effect was studied, compared to two kinds of membrane bioreactor pollutants removal efficiency, it is concluded that a better process.Experiments results and conclusions as follows:（1） The inlet water temperature from 10℃ to 25℃, p H: 5.9⁷.5, organic matter（CODcr）: 77.6mg/L⁴57.6mg/L, total nitrogen（TN）: 20.8mg/L⁵6.6mg/L, ammonia nitrogen（NH₄⁺-N）: 16.7mg/L⁴1.4mg/L, in water carbon nitrogen ratio of 4, 6, 7, 8 cases, operation facultative membrane bioreactor, sludge settling ratio was 97% and sludge volume index was 94. The effluent quality of CODcr, TN, and NH₄⁺-N was 9.2 mg/L、10.2 mg/L、2.3mg/L, respectively. The average water removal rate of CODcr, TN, and NH₄⁺-N was 96.0%、75.1% and 91.5%, respectively. Reactor effluent organic matter, total nitrogen and ammonia nitrogen in water quality can reach "urban sewage treatment plant pollutant discharge standard "（GB18918-2002） level of A discharge standards.（2） Through the study of the activated sludge of aerobic membrane bioreactor and vaccination, domestication, reactor, membrane filtration area, the mixture concentration is 6.57 g/L, SV30 was 78%, SVI was 118, the reactor effluent is stable. Reactor during start-up operation to 20 days or so, organic matter, total nitrogen, ammonia nitrogen removal effect is good. Effluent is stable. The start test completed.（3） The inlet water temperature was 7℃³0℃, p H: 6.4⁷.9, organic matter（CODcr）: 114.8 mg/L 400 mg/L, ammonia nitrogen（NH₄⁺-N）: 16.8 mg/L 29.8 mg/L, total nitrogen（TN）: 28.9 mg/L 50.9 mg/L, water carbon nitrogen ratio of 4, 6, 7, 8 cases, run the aerobic membrane bioreactor. Reactor organic matter and ammonia nitrogen effluent water quality partial can reach "urban sewage treatment plant pollutant discharge standard（GB18918-2002） level of A discharge standards. Average effluent CODcr concentration and removal rate is 17.8 mg/L, and 91.5% respectively; Average effluent concentration of NH₄⁺-N removal efficiency and 4.6 mg/L, and 80.6%, respectively, and the aerobic MBR to total nitrogen removal is only part of the water meet the national discharge standard.（4） Although the inlet water have a good quality and reaction conditions easy control in aerobic MBR. But for low carbon and nitrogen ratio sewage treatment effect is inferior to the facultative membrane bioreactor. Compared with aerobic MBR, facultative membrane bioreactor is more suitable for application in the treatment of low carbon and oxygen nitrogen sewage.（5） Compared to facultative membrane bioreactor denitrification reaction rate and rate of simultaneous nitrification and denitrification with aerobic MBR. Aerobic MBR denitrification reaction is affected by low carbon and nitrogen ratio, compared with facultative MBR. Facultative membrane bioreactor synchronous nitrification and denitrification rate is much higher than the aerobic MBR. MBR nitrogen and oxygen is mainly composed of nitrification and denitrification reaction and interaction, simultaneous nitrification and aerobic MBR are heavily dependent on traditional denitrification.