Efficiency Of Anaerobic Membrane Bioreactor (AnMBR) Treating For Sewage

The anaerobic membrane bioreactor(AnMBR)combines anaerobic biological treatment technology with membrane separation technology,with small area of land,low powerful consumption and recyclable energy producted.Meanwhile AnMBR makes the solid retention time(SRT)and the hydraulic retention time(HRT)separated effectively,with less excess sludge producted from wastewater treatment and degradation of organic matter in high efficiency.Most studies focus on AnMBR treating with high concentration organic wastewater at present,but the research on treating low concentration wastewater with su ch as domestic wastewater is few,which limit the application and devolopemnt of AnMBR.The study on AnMBR performance under medium temperature(35 ?)and room temperature condition(25?),the result showed that the mean COD removal efficiencies were 82.11% and 81.27%,and the mean effluent COD was 33.35 mg/Land 45.48 mg/L under medium temperature and room temperature condition respectively,suggesting that the medium temperature condition was more advantage than the room temperature condition.But nitrogen and phosphoru could not be removed in AnMBR.Though the fluction of wastewater character in AnMBR influent was obvious,the Reverse osmosis(RO)could make the effluent of AnMBR meet standard of wastewater reuse.The study on the characteristics of the hollow fiber microfiltration membrane fouling in AnMBR showed that: compared with the membrane fouling between medium temperature and room temperature condition,the membrane fouling under room temperature was serious.The transmemberan pressure increased rapidly,leaing to decrease membrane flux.With increasing transmemberan pressure,the particle size throughing microfiltration membran becamed smaller.And microfiltration membrane had an ability to reject microbial metabolites(SMP)containing polysaccharide and protein.With increaseinng transmembrane pressure(TMP),the reject efficiency of polysaccharide was increased,but the reject efficiency of protein was decreased.And the protein structure did not change.The study on the microbial community structure in the sludge and membrane layer sludge suggested that Proteobacteria,Chloroflex and Firmicutes were most dominant bacterial groups under the medium temperature and room temperature condition.The relative abundance of the genus Longilineal and Bellilinea was decreased,leading to reduce the COD removal efficiency at 25 ?.Bacteroidetes played a main role on membrane fouling.Besides,Gammaproteobacteria and Betaproteobacteria belonging to Proteobacteria were more advantage to adhere on the membrane surface than other bacteria,and membrane fouling was irreversible.