Biodegradation of Reactive Red 195 azo dye and Chlorpyrifos organophosphate along with simultaneous bioelectricity generation through bacterial and fungal based biocathode in microbial fuel cell

Abstract

A laboratory-scale dual-chambered bioanode and biocathode based Microbial Fuel Cell (MFC) was employed in the biodegradation of a dye Reactive Red 195 (RR195) and pesticide chlorpyrifos using bacterial and fungal strains. UV-spectrophotometery and and fourier transform infrared (FTIR) data showed removal rates of almost; 100% for both dye (150 mg/L) and pesticide (50 mg/L) with 70 and 81% Chemical Oxygen Demand (COD) in 18 h and 48 h respectively. Bio-electrochemical degradation of said pollutants was also coupled with simultaneous generation of electricity. The maximal cell potential was recorded to be 635 and 706 mV in bacterial and fungal MFC systems with corresponding power densities of 224.01 and 276.9mWm−2 respectively. Electrochemical performance of MFC reactors in term of cyclic voltammetry (CV) and chronoamperometry (CA) showed maximum electron transfer of 122 and 27.35 mA (applied voltage of −1 to +1 V (CV)) and current densities of 13.8 and 10.66mAcm−2 (CA) in the cathodic compartment where degradation of pollutants accomplished. The reactor was also tested for the simultaneous biodegradation of RR 195 dye in real wastewater along with bioelectricity production. The overall COD and colour removal efficiency was 72 %, and 95 % with concurrent increase in TDS, EC and with a maximum power density output of 519.49 mWm−2. The outcomes of this study revealed that MFC technology is highly effective in the treatment of ecological hazardous aromatic pollutants such as dyes (i.e., RR 195) and pesticides (e.g., chlorpyrifos) and for harnessing energy.