Study On The Treatment Of Domestic Sewage By Membrane Aeration Biofilm Reactor

Recently,Membrane aerated biofilm reactor(MABR)which combined membrane technology with biological treatment has become a new technology of wastewater treatment,it can remove organic matter,ammonia nitrogen and other pollutants from wastewater.It uses non-porous or microporous membrane with high oxygen permeability as a membrane component which can provide a carrier for microbial adhesion as well as supply oxygen.Therefore,MABR has the advantages of high oxygen utilization ratio,high removal efficiency and small floor area compared with the traditional bioreactor.It can effectively remove various pollutants from wastewater and has become a research hotspot in the field of wastewater treatment.Firstly,a bench-scale experiment for MABR treatment of domestic sewage which used handmade hollow fiber membrane module was carried out.During this experiment,the effect of aeration pressure and hydraulic residence time on the operation effect of MABR was studied,then the MABR was tested for low concentration wastewater treatment.Afterwards,a pilot scale test of MABR was carried out to test the performance of the MABR pilot-plant and its anti-shock loading capability.The results were showed as followed:(1)During the bench-scale,the optimal operating conditions of inlet COD 200mg/L,ammonia nitrogen 25mg/L and total nitrogen 30mg/L were the aeration pressure of 6kPa,HRT12h.(2)Under optimal conditions,COD removal rate was 87.3%,ammonia nitrogen removal rate was 97.6%,total nitrogen removal rate was 75.4%,and the dissolved oxygen in water was about 2.5mg/L.(3)Under Aeration pressure 3 kPa,HRT12h,inlet COD60mg/L,ammonia nitrogen 15mg/L,total nitrogen 20 mg/L,COD removal rate of the bench-scale MABR can reach 50.2%,ammonia nitrogen removal rate is 100%,TN removal rate is 43.2%,which means the MABR also have certain ability to treat low concentration wastewater.(4)The effluent of each pollutant of the pilot-scale MABR can reach the level A standard of Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant(GB18918-2002),when the dissolved oxygen in the MABR tank is 2-3mg/L through adjusting the blower efficiency.COD,ammonia nitrogen and total nitrogen removal rate were 92.2%,98.1%and 85.4%respectively,and the effluent SS was under 10mg/L with the removal rate of 95%.However,the effluent total phosphorus was unstable.(5)The anti-shock loading experiment indicated that when the water inflow is below26m~3/d,the effluent COD,ammonia nitrogen and total nitrogen can reach the level A standard of Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant(GB18918-2002),when water inflow achieved 32m~3/d,the effluent COD and total nitrogen can reach level A standard,but the effluent ammonia nitrogen is slightly higher than the level A standard,which means the increase of influent loading has certain influence on ammonia nitrogen removal.