Performance evaluation of Iron-doped carbon cloth cathodes in bio-electrochemical system for dye degradation

Bio electro-Fenton (BEF) is an advanced bio-electrochemical system that utilizes the synergistic effect of microbial activity and electrochemical reactions to degrade organic pollutants in wastewater. This study investigates the degradation of Chrysoidine Y dye using iron-doped, binder-free carbon cloth cathodes in a BEF system. The cathodes exhibited significant electrochemical enhancements, including increased electrochemical active surface area, improved electrical conductivity, and efficient Fe³⁺/Fe²⁺ redox cycling. Under optimal conditions (1000 mg/L substrate concentration, pH 3, 750 Ω applied resistance and 20 ppm dye concentration), the BEF system achieved 73.14 % dye removal and 58.69 % total organic carbon (TOC) reduction within 10 h. Gas Chromatography-Mass Spectrometry (GC–MS) analysis revealed the breakdown of chrysoidine Y into non-toxic intermediates. Toxicity tests using chick pea germination showed no adverse effects (Germination Index>80 %) in the treated effluent. Whole genome sequencing of the anodic biofilm identified electrogenic bacteria responsible for electron generation to drive the fenton reaction. These findings highlight the potential of iron-doped cathodes in BEF systems for sustainable and efficient treatment of dye-contaminated wastewater, ensuring effective pollutant removal and environmental safety.