Optimizing Electrocoagulation for Textile Effluent Treatment: Operational Efficiency and Environmental Assessment of Remazol Red Dye Removal

The discharge of textile industrial effluents is a major environmental concern due to their high volume and complex composition. Electrocoagulation (EC) has emerged as a cost-effective, energy-efficient treatment, especially when powered by clean energy. This study optimized standalone EC and its combination with dissolved air flotation (DAF) for treating synthetic effluents containing Remazol Red dye. Fractional factorial and central composite rotational designs were used to optimize potential difference, number and spacing of aluminum electrode pairs, treatment time, initial pH, and dye concentration. EC achieved >98% dye removal under initial conditions and >95% under the optimized model, which showed strong predictive accuracy. No dye was detected in treated samples by HPLC even at high concentrations, and complete removal occurred at lower levels. Energy consumption averaged 4.70 kWh·m^-3. Sludge generated under optimal conditions was characterized by XRD, FTIR, TGA, and AAS, indicating aluminum oxyhydroxide formation, with potential conversion to aluminum oxide above 293 °C. Results support EC as a viable, sustainable strategy for textile wastewater treatment and resource recovery.