Electrochemical Treatment of Reactive Orange 16 Dye Pollutant Using Microbial Fuel Cell as Renewable Power Source

Electro-Fenton (EF) process plays an effective role for organic pollutant degradation, although it required nonsustainable electrical power source to produce hydrogen peroxide (H2O2). Two-chamber microbial fuel cells (MFCs) have been proposed for pollutant treatment using Fenton-based reactions, but these MFCs generate low-power densities and required expensive membranes. Here, we proposed a more efficient dual-reactor system with single-chamber MFC as renewable power source for dual cathodes electro-Fenton (DCEF) process treatment of reactive orange 16 (RO16) dye as model pollutant. The MFC was fabricated with a low-cost earthen pot (volume = 750 mL) using a carbon felt anode and carbon cloth air cathode, respectively. For the DCEF chamber, two cathodes: graphite plate (C1) and stainless steel (C2) were used for simultaneous H2O2 production and activation. The MFC produced the maximum power (Pmax) of 20.8 mW at an organic loading rate (OLR) of 6.5 g COD/L/day. For any higher OLR ≥6.5 g COD/L/day, the MFC shows an overloaded organic substrate condition which resulted in a reduction in system efficiency. It was found that complete degradation of RO16 dye and 79 ± 1.5% of total organic carbon removal was achieved in one cycle (16 h) of the dual reactor system. Compared to the previously developed single-cathode EF process, the degradation efficiency of the DCEF process was considerably improved. The results of the developed dual-reactor system show efficient removal of RO16 persistent organic pollutants that would advance the practical application of the EF treatment process.