Membrane Fouling Mitigation Strategies And Wastewater Treatment In Anaerobic Baffled Membrane Bioreactor

With the rapid development of social economy,water shortages are intensified increasingly.In order to alleviate the severe water shortages,wastewater reuse has become the key to solve the problem of water shortage.Membrane bioreactor?MBR?has been recognized widely by many scholars for having high stability,simple process,easy control,excellent effluent quality,small footprint and low excess sludge production,which has advantages over traditional wastewater treatment technology.However,membrane fouling problem is a barrier restricting its commercial application.Anaerobic baffle reactor?ABR?is a multi-stage anaerobic bioreactor which is composed of a series of vertical baffle.the distance of sewage flows is lengthened,and the pollutants are degraded step by step during sewage flow through it.This study proposed a novel anaerobic baffled membrane bioreactor?ABMBR?which was composed by AnMBR/MBR and ABR and was operated at room temperature,including two phases of experiments.In the first phase of experiment,the raw wastewater for influent was drawn from the sewer at the campus.The whole system was operated for 130 days.The results indicated that the removal ratio of COD reached about 53%and 83.72±10.97%of turbidity,28.21±8.29%of UV₂₅₄,16.51%of tryptophan and 37.61%of humic-like substrates were removed by the system.During the operation,taking back-flushing,physical flushing and chemical cleaning as the membrane fouling control method.The results indicated that the membrane fouling developing rate was 0.0012⁰.0021 MPa/d under stable condition,the polysaccharide accounted for 6.85±3.1%amount of total filter cake and the protein accounted for 4.12±2.1%.The submicron particles in supernatant with 0.35±0.02?m of particle size and-25.20±1.83 mV of Zeta potential,were considered as the main membrane foulants,which were composed of polysaccharide,protein and humic-like substrates.In the second phase of experiment,the beer wastewater for influent was drawn from the Xi'an Hans brewery.This system was operated for 140 days.The brewery wastewater treatment and membrane fouling mitigation strategies were studied comprehensively,During anaerobic treatment process in this study,the chemical oxygen demand?COD?removal ratio of brewery wastewater could be maintained at 73.87%when the hydraulic retention time?HRT?was reduced from 42.44 h to 22.60 h.For membrane fouling mitigation in AnMBR,regular aeration was more effective than back-flashing,and the fouling could be inhibited further when both controlling ways were adopted at the same time.For membrane fouling mitigation in AnMBR of this study,only 0.52%⁰.99%of electric energy was required,but 31.80%of energy was needed in MBR.The research work confirmed that the pollutants in wastewater could be removed effectively by ABMBR,which provided a beneficial exploration in the expanding application of MBR in wastewater recycling technology and theoretical basis for its market development simultaneously.