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

Abstract

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.

Key findings

• ▸The system achieved high biohydrogen production rates and sulfate removal efficiencies.
• ▸The heat-pretreatment step improved the system's performance and stability.
• ▸The bioelectrochemical system also showed potential for nitrate removal.

Keywords

Identifiers

DOI

10.1007/s00203-022-03352-4

PubMed

36454386

Journal

Archives of Microbiology

Year

2023