Biohydrogen production potential with sulfate and nitrate removal by heat-pretreated enriched sulfate-reducing microorganisms-based bioelectrochemical system.

In this study, heat-pretreated sulfate-reducing bacteria (SRBs) were evaluated for simultaneous sulfate and nitrate removal in a bioelectrochemical system (BES). The effect of the applied potential of 20 mV to SRBs was evaluated at a sulfate concentration of 3 g/L and/or nitrate concentration of 0.5 g/L supplemented before heat pretreatment for sulfate and nitrate removal. The highest H ₂ production of 2.24 ± 0.04 mM/L in heat-pretreated culture was observed in the presence of sulfate at an applied potential of 20 mV (BHE-S). Simultaneous reduction of sulfate and nitrate was significant in BESs supplemented with either sulfate or nitrate during heat-shock pretreatment of the culture. The highest SO ₄ ^2- removal of 88.91 ± 0.8% was found in culture heat pretreated with NO ₃ ^- and applied with 20 mV potential (BHE-N). The kinetics of heat-pretreated culture showed higher R ² and ultimate potential for H ₂ on the continuous application of 20 mV potential.
(© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)