The Start-up And Performance Of AMBR-MABR Coupling Process Treating Synthetic Livestock Wastewater

With the large-scale development of livestock industry in China,livestock wastewater has become an important source of agricultural pollution.In this study,a coupling process of anaerobic migrating blanket reactor-membrane aeration biofilm reactor(AMBR-MABR)was employed to treat the livestock wastewater,and its start-up,pollutant removal and operation characteristics were explored accordingly.For this coupling process,the start-up mode and optimized operation parameters were determined,then its feasibility for treating the livestock wastewater was assessed as well.The start-up was studied for AMBR-MABR to treat synthetic livestock wastewater.The corresponding sludge of ABR-MABR were employed as the seed for AMBR and MABR compartments,respectively,and then the start-up was conducted by the fixed hydraulicretention time(HRT)and the stepwise increase influent load.The duration of start-up time lasted 83 d until the organic loading rate(OLR)reached 7.5 kg COD/(m3·d).After start-up,the average removal rates of COD,NH4+-N and TN for AMBR-MABR could approach about 83.96%?37.56%and 38.29%.Their median diameters were 0.25-0.74 mm in anaerobic compartments and 0.18mm in aeration ones.The surface of mature sludge in AMBR-MABR was uneven and porous.The mature sludge was mainly composed of bacillus,coccus,beads and extracellular polymeric substances(EPS).The microbial communities were abundant.Propionibacteriaceae_uncultured showed the highest abundance.The identified Eubacteriaceae uncultured,Mesotoga indicated the occurrence of butyric acid and formic acid acidification process in the mature sludge of ?-? compartments.The high abundant methanogenic bacteria and archaea were Smithella?Leptolinea?Synergistaceae_uncultured,Methanosaeta,Methanobacterium,and Archaea_unclassified.In addition,Nitrospira was also identified.The microbial community could be divided into 3 clusters:? and ?,? and ?,? and ?.During the running of AMBR-MABR at the optimal operating conditions of T=32?,"8+4" mode and HRT=24 h,the removal efficiencies of COD and NH4+-N could approximately approach 90%and 50%when the concentration of COD and NH4+-N in the livestock wastewater were 8470 mg/L and 513 mg/L,respectively.