Removal of COD, phenols and ammonium from Lurgi coal gasification wastewater using A2O-MBR system

► Anaerobic-anoxic-aerobic MBR system treated the coal gasification wastewater. ► COD removal rate was 97.4% with effluent concentration less than 100 mg/L. ► NH4+-N removal rate was 92.8% with effluent concentration less than 12 mg/L. ► HRT and recycle ratio strongly affected the performance of the system. ► GC/MS analysis found refractory organic removal in anaerobic and anoxic stage.