Simultaneous electricity generation and sirius red azo dye degradation using brewery wastewater as carbon source in a microbial fuel cell

Microbial fuel cells (MFCs) are attaining great interests for simultaneous current generation and recalcitrant organic pollutants treatment. Earlier investigations have revealed barley brewery wastewater as a cheap carbon source for simultaneous electricity generation, chemical oxygen demand (COD) removal, and poly azo dye (Sirius Red) degradation in a dual chamber microbial fuel cell. The experimental results showed a stable voltage production of 0.39±0.02 V (220 Ω external resistor) using brewery wastewater as a sole carbon source. The maximum power density achieved was 271±21 mW/m² at an initial brewery wastewater concentration of 1000 mg/L COD, with the addition of dye (100 mg/L). A decolorization efficiency of 67% was attained in the anode chamber, and COD removal was 90% and 78% for brewery wastewater before and after the addition of dye, respectively, in a 48-h batch studies. UV-vis, Fourier transform infrared confirmed that the azo bonds in the dye were cleaved during dye degradation. Gas chromatography-mass spectrometry showed sodium-4-aminoazobenzene-4′-sulfonate and 1-3-bis(2-aminonapthalen-6-yl) urea as the main metabolites after the decolorization of Sirius Red.