The aim of this study is to evaluate the impact of SRT (infinite, 60 and 30 days) on the treatment and filtration characteristics of sequential anaerobic sulfate-reducing and aerobic sulfide-oxidizing MBRs treating textile wastewater. The influent COD, dye and sulfate concentrations were kept constant at 2000, 200 and 1000 mg/L, respectively. The decreased SRT caused substantial and partial decreases in COD oxidation and sulfate reduction, respectively, due to decrease of biomass concentration. Complete color removal was observed in the AnMBR and a slight increase in color was detected in the AeMBR. Sludge filterabilities were assessed with specific resistance to filtration, capillary suction time, and supernatant filterability tests. Compact and non-porous cake layer formed in the AnMBR. Metal-sulfide and Ca-P were detected in the cake layers of AnMBR and AeMBR, respectively, by SEM-EDS analyses. Desulfiiromonas thiophila and Thioalkalivibrio sulfidiphilus were dominant sulfate-reducing and sulfide oxidizing bacteria in AnMBR and AeMBR, respectively. (C) 2016 Elsevier B.V. All rights reserved.