Optimization of electrocoagulation process for individual and simultaneous removal of cadmium and copper from simulated wastewater

Abstract

This study delves into electrocoagulation for removing copper and cadmium from synthetic water, exploring both individual and binary removal. Employing the Box‒Behnken design method, the research fine-tuned process operating factors including current density (10 to 50 mA/cm2), starting pH (3 to 7), and metal ion concentration (100 to 300 ppm). Optimal conditions for single-element systems yielded 99.02% copper removal (pH value of 5.63, current density value of 50 Am-2, copper concentration 100 ppm) and 98.45% cadmium removal (pH 6.15, current density 50 A/m2, cadmium concentration 124 ppm). Findings underscored the substantial current density impact on removal efficiency, surpassing the effect of pH and metal ion concentration. Notably, the current played a more pivotal role in cadmium removal than in copper removal. A robust R2 analysis of variance (98.85% for Cu and 99.50% for Cd) confirmed the satisfactory agreement between the second-order regression model and the experimental data, affirming the optimization validity of the electrocoagulation process. In binary systems, copper presence hindered cadmium removal, reducing efficiency from 63.63% to 50.91%. Conversely, the inhibitory effect on copper removal was comparatively lower due to copper's stronger selectivity towards Al(OH)3.