RESUMEN
A pilot-scale single-stage anaerobic fluidized membrane bioreactor (AFMBR) was firstly used in this study to treat cold-rolling emulsion wastewater from steel industry. It was continuously operated for 302â¯days with influent COD concentration of 860-1120â¯mg/L. Under a hydraulic retention time of 1.5â¯d, the average effluent COD concentration of 72â¯mg/L achieved corresponding 90% of COD removal. The permeate flux was varied between 1.7 and 2.9â¯L/m2/h during operation which decreased with increased biomass concentration inside AFMBR. The trans-membrane pressure (TMP) was generally around 35-40â¯kPa, however, it increased up to 60â¯kPa when volatile suspended solid increased to above 2.5â¯g/L. Both flux and TMP data reveal the importance of biomass control for AFMBR operation. Results from terminal restriction fragment length polymorphism (T-RFLP) show the genus Methanosaeta was dominant on GAC and it shared dominance with the genera Methanomethylovorans and Methanosarcina in suspended sludge.