Influence of Fe2+ and Fe3+ on the Performance and Microbial Community Composition of a MFC Inoculated with Sulfate-Reducing Sludge and Acetate as Electron Donor

A sulfidogenic sludge supplemented with acetate was evaluated in the anodic chamber of microbial fuel cells (MFCs) presence sulfate (SO4-2)/Fe3+ and (SO4-2)/Fe2+ to investigate MFC performance effect iron ions on composition community since are frequently present wastewater derived from several anthropogenic activities. The current densities were up 0.025 mA/cm2 0.017 for MFCs Fe2+ Fe3+, respectively. Accordingly, redox activity slightly higher than Fe3+. In general, metabolic system Fe3+ reaching a percentage reduction (% SR), sulfide concentration (mg/L HS-), removal chemical oxygen demand COD removal) 35.2 ± 0.75 , id="M2"> 450.3 3.6 id="M3"> 50.05 0.24 % SR, HS-, COD, respectively, whereas percentages id="M4"> 30.1 1.076 id="M5"> 220.6 2.0 id="M6"> 11.78 10.81 population determined each also correlated activity. Rhodospirillales, Caulobacterales, Burkholderiales most abundant orders bacteria Fe2+, Rhodobacterales, Sphingomonadales, Rhizobiales. Desulfohalobiaceae Desulfovibrionaceae identified Fe2+. Unexpected interactions combinations microorganisms observed relatively short culturing time, demonstrating importance characterizing anode biofilm prior shifts ion concentrations long-term basis.