Modeling and Optimization of Arsenite Removal from Groundwater Using Al Ball Anodes by Electrocoagulation Process

Abstract

Electrocoagulation (EC) was applied for the present investigation to remove high concentration of As(III) (100-1000 µg/L) from groundwater. The effects of seven operating parameters such as initial pH, current, operating time, size of Al ball anode, initial As(III) concentration, height of Al in the reactor and air flow rate as well as their interactions on arsenite removal efficiency and operating cost were evaluated with a three level factorial design viz, Box-Behnken statistical experiment design method. Sixty-two experiments were carried out for construction of a quadratic model. The results indicated that current, operating time and concentration were significantly affected for As(III) removal efficiencies in the EC process. The model predicted for maximum removal efficiency of arsenite and minimum operating cost at the optimum operating conditions (5.89 of pH, 0.17 A, 21.79 min, ball size of 7.75 mm, column height of 8 cm and airflow of 4 L/min) was 99.94% and 0.642 $/m³ for initial As(III) concentration of 1000 µg/L. This study showed that the model was adequate for meeting the permissible limit value of <10 µg/L.