Evaluating the performance of an electrocoagulation process using response surface methods for textile wastewater treatment

Abstract

The textile industry is one of the largest polluters of water resources, producing effluents containing complex mixtures of pollutants such as dyes, heavy metals, and high biological oxygen demand. Electrocoagulation (EC) is an efficient wastewater treatment technique that uses iron or aluminum electrodes to coagulate and adsorb pollutants. This work assesses the performance of EC for textile wastewater treatment to identify the best combination of pH (5-9), electrolysis time (20-60 min), and voltage (5-11 V) on Chemical Oxygen Demand (COD) and color removal. The results show that voltage and electrolysis time had a positive effect on the efficiencies of pollutant removal, reaching the maximum efficiency of 70.06 and 87.36 when pH was 7, electrolysis time 60 min, and 11 V. The quadratic regression models obtained by Response Surface Methodology (RSM) had good predictive ability with the adjusted R² of 0.9684 for COD and 0.9843 for color. Statistical significance of the pH, voltage, and their interaction was further verified using the ANOVA test as significant factors that helped to explain the treatment effect. This study also highlights the possibility of using EC as a cost-effective and energy-saving technology compared to conventional chemical coagulation and advanced oxidation processes, with satisfactory treatment obtained at modest voltage and time demands. The study contributes to the knowledge of parameter optimization and enhances the applicability of EC in reducing the effects of textile effluents on the environment.