Simultaneous biohythane production and sulfate removal from rubber sheet wastewater by two-stage anaerobic digestion

The sulfate-reducing bacteria (SRB) consortium (Desulfovibrio sp. Desulfitibacter sp. Dethiosulfatibacter sp. and Clostridium sp.) was investigated for sulfate removal and biohythane production from rubber sheet wastewater (RSW). The RSW at COD/SO42- ratio of 13 and pH 6 was suitable for sulfate reduction and biohythane production. Hydrogen yield, sulfate emoval efficiency, and methane yield were 101 mL H-2.gVS(-1), 87%, and 629 mL CH4.gVS(-1), respectively. The hydrogen and methane production rate was 14.53 mL H-2.d(-1) and 45 mL CH4.d(-1), respectively. Hydrogen effluent with trace element supplemented improved hydrolysis rate (k(h)) from 0.19 d(-1) to 0.23 d(-1) and methane production rate from 31-48 to 42 -97 mL CH4.d(-1). The COD removal of RSW in acidogenic stage and methane stage was 11.3% and 72.4-76.2%, respectively. The sulfate removal of RSW in acidogenic stage and methane stage was 87% and 9%, respectively. Two-stage anaerobic fermentation obtained simultaneous biohythane production and sulfate removal with efficiently for energy recovery from RSW. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.