| Landfill leachate from a composing field of a finished municipal waste landfill contains high concentration organic matters and toxic substrates. It has been one urgent task that the pollution control and treatment of landfill leachate for environmental engineers in nowadays. The research development and application of membrane bioreactor has gotten more attention in treating high concentration organic wastewater. In the paper, from lab-scale experiment to pilot study, the performance of anoxic-submerged oxic in landfill leachate treating and the development of membrane fouling was systemically investigated.The results of lab-scale experiment showed: the average removal efficiency of COD being achieved 92%,which including anoxic donation 23.6%, oxic donation 50.7% and membrane donation 15.3%;The results also showed the proper process parameters are DO 2-4mg/L,MLSS 9000mg/L,HRT 20-24h,recycling rate 1-2,C/N 5:1 and SRT 13d respectively in the experiment;Membrane module resistance (Rm) and Sludge layer resistance (Rc) of total resistance(Rt) is 98.19%,during actually membrane filtration, Rm is the key factor in membrane filtration,and sludge cake accumulation is the main reason of membrane fouling;For long term operation and staying the velocity of membrane fouling,effluent flux should be controlled less than critical flux. Experiment date showed the lower membrane flux the longer membrane cleaning period.The operation result of UASB combined with A-SOMBR treating leachate:when volumetrical loading rates were in the range of 0.76-1.61kgCOD/(m3·d), the average removal of COD was 82.66% and the average value of COD in effluent was 188.46mg/L;When volumetrical loading rates in range of 0.058-0.23kgNH3-N/(m3·d),the removal of NH3-N was 88.22% and NH3-N concentration declined to 27.02mg/L.The pilot-scale experiment of UASB combined with micro-electrolysis and blow-off(imitating)+A-SOMBR showed:Micro-electrolysis is an effective method to pretreat landfill leachate. It not only can remove much of COD, chroma , humic acid but also can improve leachate's biodegradable ability to create a good condition for following biochemical treatment. In continues feed experiment implied that when the volume ratio of iron slag and coke is 1:3 and HRT is 1h, the removal rate of COD and chroma could reach 68%, 91% respectively; BOD/COD is increased from 0.3 to about 0.5. When the average concentration of COD in influent was about 1092mg/L,the average COD in effluent was 254.15mg/L;After meliorate the ratio of C to N to achieve 5:1 by adding carbon source,the average removal of NH3-N was achieved 88.36%,the average concentration is 24.33mg/L;Micro-electrolisis play an important role for the removal of chorma,which made chroma 1000~1600 lowed to 100~200;The noval flat-sheet membrane module showed a good performance in resisting fouling. The system had been operated stable for 90 days just by souring and back-washing for the recovery of membrane flux. The research result implied that cleaning by permeate stoppage and back-washing is more effective when applied in the early stages of filtration, rather than being attempted later when heavily fouled.
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