Simultaneous electricity generation and sulfide removal via a dual chamber microbial fuel cell

Abstract

Microbial fuel cells (MFCs) have recently been used to alter different sources of substrates to produce bioelectricity. MFCs can also be used for wastewater treatment and electricity generation simultaneously. Sulfur compounds such as sulfides commonly exist in wastewater and organic waste. In this study a dual chamber MFC was constructed for power production. Sulfide was used as the electron donor in the anaerobic anode compartment. A mixed culture of microorganisms was used as an active biocatalyst to convert the substrate into electricity. The obtained experimental results illustrated that the MFC can successfully alter sulfide to elementary sulfur while generating power. The initial concentration of sulfide in the anode compartment was 0.4 g l-1 and it was completely removed after 3 days of MFC operation. The influence of oxygen was examined in the cathode chamber and the cell voltage gradually increased during aeration, reaching 480 mV after 1200 s. Hexacyanoferrate was added to the cathodic solution in different concentrations and its effects were investigated. The maximum generated voltage, power and current density were 988.9145 mV, 346.746 mW.m-2, 1285.64 mA.m-2, respectively and they were obtained in the presence of 1.4 g l-1 of mediator.