Study On Influence Factors Of UF Membrane Pollution And Combined Process High Efficiency Sedimentation Tank With UF

In recent years,applications of UF process in water supply have been the rapid development,and has gradually become the most promising treatment technologies and processes,but membrane fouling has been difficult to resolve technical problems,UF has the higher requirements of water quality.In this paper,adopting the the PVC hollow fiber external pressure immersed UF membrane,study on the influence factors of the membrane pollution from particles accumulation in membrane tank,and removal efficiency of high organic matter,high-algae in the Yellow River Basin downstream of raw water using combined Process high efficiency sedimentation tank/ internal pressure UF.Through operating parameters of PVC hollow fiber external pressure immersed UF membrane debug tests,educe the basic operation of UF membrane:First,go through a number filter cycle containing the process of filtration and intermittent aeration,and then,the anti-wash cycle containing dumping sewage and anti-wash process.In experimental stage,found that maximal variable turbidity of reactor in unit aeration cycle.By means of analysis,experiment results showed that decrease of turbidity in tank was particulate matter adsorbed to UF during the UF operation.In filtration cycle period,there was a relativity between raw water turbidity and transmembrane pressure in membrane tank.The pressure-turbidity ratio could state membrane pollution degree well from particles accumulation in membrane tank.According to the link of pressure-turbidity ratio in backwash cycle,the method of estimated concentration polarization resistance was established,after that studying the relationship of concentration polarization resistance and decrease of turbidity of membrane of unit and the compound cake-layer resistance , and establishing compound cake-layer resistance growth model in aeration cycle.Results indicated that there was a relationship of unary-cubic function between concentration polarization resistance and decrease of turbidity of membrane of unit.When decrease of turbidity of membrane of unit greater than 3.6 NTU/m2,the concentration polarization phenomena is more serious.The value is used as a foundation for determining the operation cycle.There were two positive correlation:between growth speed rate of compound cake-layer resistance and turbidity of tank,between standard deviation of compound cake-layer resistance growth model and decrease of turbidity of tank.The fitting curve of compound cake-layer resistance growth model in aeration cycle is in line with the natural curve of the exponential distribution.The experimental results of combined process high efficiency sedimentation tank with UF showed that significantly improved removal efficiency of CODM n and Ammonia nitrogen by increasing the dose of Powdered Activated Carbon,and there are excellent removal efficiency in turbidity,algae,Bacteria and Escherichia Coli Group aspect.