Enhancing lead ion removal from simulated wastewater through continuous electrocoagulation process: investigating operating parameters and adsorption behavior

Electrocoagulation, a promising method for the removal of contaminants from aqueous solutions, was investigated in this study. The effects of different operational parameters on the removal of lead ions were examined using a continuous electrocoagulation process in an 800 ml electrocoagulation cell. The experimental setup involved varying the hydraulic retention time HRT (15, 25, 35, and 45 min), applied voltage (2, 5, 7.5, 10 V), the rotation speed (0, 50, 100, and 150 rpm), and the distance between the electrodes (2.3 and 2.7 cm). The initial concentration of lead ions in the aqueous solution was set at 200 mg Pb⁺²/L. The results revealed that an extended HRT significantly enhanced the removal efficiency of lead ions, with the maximum efficiency attained at a 45-min HRT. Increasing the applied voltage up to 10 V also improved the removal efficiency. However, as the distance between the electrodes increased, the removal efficiency decreased. Regarding the rotation speed, an increasing trend in removal efficiency was observed up to 100 rpm. Beyond this threshold, the removal efficiency gradually declined due to the destabilization of the formed flocs. The best removal efficiency for lead ions is 97% at the following operating conditions; HRT is 45 min, applied voltage 10 V, and rotational speed 100 rpm at distance between the electrode is 2.3 cm while initial lead ion concentration 200 mg/L, current density is 4 mA/cm² and pH solution is 7.

Graphic abstract