MABR Membrane Material Selection Optimization And The Effect Of Microfluidic Field On Biofilm Performance

Membrane aerated biofilm reactor(MABR)is a new wastewater treatment technology combinated the membrane technology and biological treatment technology.Based on the method of numerical simulation,the internal hydrodynamic characteristic of MABR was investigated.The removal performance of carbon source and nitrogen in MABR was investigated under different process parameters.The comparison of Polyvinylidene fluoride(PVDF)and Polypropylene(PP)as aeration membrane material was evaluated in membrane-aerated biofilm reactors(MABRs).MABR equipped with PVDF membrane achieved higher removals of COD(above 94.2%)and TN(77.6%)compared with those of MABR with PP membrane(85.3%and 61.4%,respectively),as well as better membrane fouling cotnrol.Based on scanning electron microscope(SEM)and atomic force microscopy(AFM)observation,there were significant difference in surface structure between PVDF membrane and PP membrane.The surface of PP membrane was more smoothly than that of PVDF,which led to more serious membrane fouling and less oxygen transfer rate.The results also indicated that biomass on PVDF and PP membrane fibers were 26.22 and 21.87 g/m,respectively.It is suggested that the PVDF membrane could be a preferable material used in MABR.On this basis,according to the result of simulation optimization of reactor,flow field area,local flow field with different fiber in component is studied on the microbial population characteristics and the influence of the biofilm.The experimental results show that the micro flow field of biological membrane density,thickness and population distribution has a significant effect and the influence of various stages each are not identical,the early because the biofilm is not yet mature,especially the import and export areas are greatly influenced by the shear stress and dissolved oxygen,uneven distribution of AOB and NOB,as the reaction progresses,the reactor in different regions in population distribution is relatively uniform,but due to the membrane pollution is more serious,the oxygen transfer rate decline faster than before.