Simultaneous sulfide removal and hydrogen production in a microbial electrolysis cell

Abstract

Sulfide removal and hydrogen production in a microbial electrolysis cell (MEC) were simultaneously accomplished using potassium sulfide as the substrate. Experiments were conducted utilizing a singlechamber MEC under the applied voltage of 0.7 V with different concentrations of potassium sulfide (i.e., 500, 600, 800, and 1000 mg/L). MEC test results indicated that the optimum concentration of potassium sulfide was 600 mg/L with a maximum hydrogen production rate (QH2) and overall energy recovery (ηw+s) of 0.913±0.023 m3H2m-3d-1 and 261%±6.5%, respectively. The sulfide removal rate was 80.7%. Microbial community analysis of the anode biofilm showed an extensive diversity of bacteria, including Geobacter(7.35%), Desulfurella(4.31%), Sulfuricurvum(3.33%), and Sulfurospirillum(2.82%). This study presents a new and effective method for sulfide removal.