OEX_高_2404202217

The reactor can use both organic matter in the water and hydrogen reduced by the cathode as an electron supply for sulfate reduction. A 40h hydraulic retention time (HRT) yielded a 33.6% higher sulfate reduction rate in R4 than in R1. Sufficiently prolonged HRT has a negative effect on sulfate reduction. When the COD/SO42- influent ratio decreased from 1.7 to 1.3, sulfate removal rate decreased from 70.47% to 32.82%. Optimal conditions for reactor operation were an HRT of 60 h, COD/sulfate ratio of 1.7, and current of 50 mA. These conditions achieved a sulfate removal rate of 70.47% and a COD removal rate of 85.58%. The reactor had higher abundance of Proteobacteria, Bacteroidetes, Euryarchaeota, and Chloroflexi phyla.