Abstract
The treatment of industrial effluents containing high salinity alongside recalcitrant organic contaminants poses significant challenges to conventional biological and chemical remediation systems. In this study, a novel electrochemical-Fenton (EF) process utilizing an advanced carbon-polytetrafluoroethylene gas-diffusion cathode paired with a dimensionally stable Ti/RuO2-IrO2 anode was systematically evaluated for the degradation of complex organic pollutants in hypersaline wastewater (total dissolved solids up to 35 g/L NaCl). Operational parameters, including current density (10–50 mA/cm2), initial pH (2.0–8.0), ferrous catalyst dosage (0.1–1.0 mM), and electrolyte salinity, were investigated to elucidate degradation mechanisms and optimize treatment performance. Under optimal conditions (current density of 30 mA/cm2, pH 3.0, and 0.5 mM Fe2+), the system achieved 94.2% chemical oxygen demand (COD) reduction and 81.6% total organic carbon (TOC) removal within 120 min. Quenching experiments and radical quantification demonstrated a synergistic oxidation pathway governed simultaneously by electro-generated hydroxyl radicals (•OH) and electro-activated chlorine species (HClO/ClO− and Cl2•−), which effectively mitigated chloride-induced radical scavenging. The electrical energy per order (EE/O) was calculated at 14.8 kWh/m3/order, representing a 38% energy reduction compared to conventional EF setups. These findings demonstrate that the integrated EF system provides a robust, energy-efficient, and sustainable solution for the remediation of refractory pollutants in hypersaline industrial water matrices.
