Experimental Study On Treatment Of Domestic Sewage By Membrane Aeration Bioreactor And Enhanced Phosphorus Removal

Membrane Aeration Bioreactor(MABR)is a new type of wastewater treatment process and it combines membrane aeration and bioreactors.It has the advantages of bubble-free aeration,special biofilm structure,simultaneous nitrogen and carbon removal.It has unique advantages in the treatment of domestic sewage and great prospects in engineering application.In this paper,the MABR reactor use the PVDF hollow fiber membrane to build the membrane module.The MABR reactor adopts the sequencing batch operation mode.This paper carries out experimental research on the nitrogen and carbon removal operation parameters of the MABR system.Through the construction of activated sludge + MABR system,the experimental research on enhanced phosphorus removal by activated sludge MABR composite process was carried out.According to the research results of nitrogen and carbon removal operation parameters of the MABR system,when the reaction time is 11h(anaerobic 3h + aerobic 8h),dissolved oxygen is about 1.0mg/L and C/N ratio is about 5,the sewage treatment effect of the MABR system is good.,and the effluent water quality is stable;The removal rates of COD,ammonia nitrogen and total nitrogen can reach 92.2%,90.9% and 82.7%,respectively.The effluent concentrations are 23.41 mg/L,5.0 mg/L,10.38 mg/L.They all meet the national first-class A emission standards.However,the MABR system only relies on the growth and shedding of the biofilm attached to the surface of the membrane to carry out biological phosphorus removal,and the phosphorus removal effect is not satisfactory,only about 30%.According to the results of enhanced phosphorus removal research of activated sludge MABR composite system,when the reaction time is 7.5h(anaerobic 3h + aerobic 4h +precipitation 0.5h),dissolved oxygen is about 2.0 mg/L,C/N ratio is 8,sludge age is 15 d,thetreatment effect is ideal.The removal rates of COD,ammonia nitrogen,total nitrogen and total phosphorus are 96.1%,86.6%,75.8% and 88.7% respectively.The effluent concentrations are18.72 mg/L,7.37 mg/L,14.52 mg/L and 0.68 mg/L.All effluent concentrations meet national first-level emission standards.According to the comparison research results of the traditional MABR system and the activated sludge MABR composite system,the COD,ammonia nitrogen and total nitrogen removal rates of the two systems are not much different;however,the activated sludge MABR composite system is superior to the traditional MABR system in phosphorus removal.The activated sludge MABR composite system has the feasibility of completing simultaneous nitrogen and phosphorus removal.