Study On The Performance Optimization Of MABR For Treating Micro-polluted Landscape Water And Its Membrane Pollution

The landscape water was micro-polluted caused by a large amount of nutrients such as nitrogen and phosphorus entering the landscape water,resulting in eutrophication of the water.The concentration of dissolved oxygen in the water is greatly reduced,resulting in the proliferation of plankton and other plankton,which causes the quality to deteriorate,producing a foul smell and clear.In a series of water treatment processes,MABR can quickly and effectively remove pollutants from micro-polluted water bodies,which has broad application prospects.The process effectively combines the biofilm process with the membrane separation technology,and has now become a promising wastewater treatment process.According to the properties of low carbon and high ammonia nitrogen in micro-polluted water,the treatment performance of MABR process was studied.The removal effects under different aeration pressures,different membrane loadings,different carbon-nitrogen ratios and different pH conditions were studied.The effects of surface load,C/N ratio,pH and alkalinity on the performance of the system for the treatment of micro-polluted landscape water.Studies have shown that when the influent pH is controlled at 8.0,the COD was 50mg/L,and the NH3-N was 10mg/L,the maximum removal rate of COD in the reactor under different membrane COD loading was 90.5%(loading 2g/(m2·d));The maximum removal rate of ammonia nitrogen by the reactor under different ammonia nitrogen loading was 92.83%,and the maximum removal rate of total nitrogen was 85%(load is 0.6g/(m2·d)).Then the kinetic equations of degradation of micro-pollutants in MABR system were studied.Under the optimal experimental conditions,the kinetic equations of MABR degradation of COD and NH3-N were obtained.The membrane fouling mechanism of long-running MABR was studied.It can be determined by different aeration methods that unfiltered air will have certain impact on membrane fouling,but the impact was not very large,mainly due to pollution entering the membrane section during long-term operation.Blocking the loose layer results in a decrease in MABR treatment performance.In the EPS formed on the outer wall of the hollow fiber membrane,the gel layer formed by the polymer of the protein and the polysaccharide hinders the mass transfer of oxygen,but some soluble organic substances such as bacteria can enter the loose layer of the section,thereby causing membrane fouling.Among the four organic components in the biofilm EPS,the hydrophobic membrane was hydrophilized mainly by the hydrophilic substance,thereby forming membrane fouling,reducing the oxygen mass transfer rate of the membrane,and reducing the treatment performance of the MABR by long-term operation.