Operation character of membrane bioreactor in treating the water of micro-polluted water source

The application of membrane bioreactor (MBR) in treating the water of micro-polluted water source has received much concerns recently in the domain of water environment. In this paper, the operation character of suspended growth type of MBR and three adhesive growth types of MBR in treating the water of artificially simulated micro-polluted water source was investigated. Experiment results showed that these 4 MBRs had ammonia nitrogen removal rate over 85%~90%. MBRs filled with nubby filler or powdered activated carbon (PAC) were more effective to remove organic matters than MBR filled with zeolite powder and MBR of suspended growth type. HRT had very little effect on removals of organic and ammonia nitrogen when HRT was 2 to 4h. The organic removal rate of PAC-MBR system, particularly the removal rate of UV254, was affected by PAC addition amount and saturation degree. When PAC addition amount was increased over 1000 mg/L and before PAC was saturated, UV254 removal rate could be improved by about 25% compared with that of MBR with nubby filler. After PAC was saturated, these two systems had almost same organic removal rate. With regard to the membrane permeability in continuous operation, the difference between MBR with PAC or nubby filler added and MBR of suspended growth type was small; while MBR with zeolite powder was the lowest. Changing the addition amount of PAC had little effect on the membrane permeability in PAC-MBR.