Biodegradation of reactive red 120 in microbial fuel cell by Staphylococcus equoruma RAP2: Statistical modelling and process optimization

Abstract

A laboratory-scale Microbial Fuel Cell (MFC) is used for the degradation of reactive red 120 (RR120) using bacterial strain Staphylococcus equorum RAP2 (Accession number MW36539) isolated from wastewater treatment plants capable of degrading 100 % of dye (100 ppm) in 72 h at pH 7 efficiently. The effect of pH, concentration, and time on dye degradation and electricity generation were studied using Center Composite Design (CCD) combined with Response Surface Methodology (RSM). Predicted values (R2 0.9920) for dye degradation and (R2 0.9428) current density was found to be high with P-value <0.05. A quadratic model was best fitted with the experiment. The optimized solutions obtained through RSM were also validated with experiments (±0.5 % error). Analytical techniques such as Fourier-transform infrared spectroscopy (FTIR), Liquid chromatography, and mass spectroscopy analysis (LCMS) were used for establishing the phenomena of biodegradation. Metabolite toxicity was also assessed by phytotoxicity. © 2021 Elsevier Ltd