Arsenite removal from groundwater in a batch electrocoagulation process: Optimization through response surface methodology

In this study, influences of seven process variables such as initial pH (pH _i ), applied current (i), operating time (t _EC ), initial As(III) concentration (C _o ), diameter of Fe ball anode (d _p ), column height in the electrocoagulation (EC) reactor (h) and airflow rate (Q _air ) for removal of As(III) from groundwater by a new air-fed fixed-bed EC reactor were evaluated with a response surface methodology (RSM). The proposed quadratic model fitted very well with the experimental data for the responses. The removal efficiencies and operating costs were determined to be 99% and 0.01 $/m ³ at the optimum operating conditions (a pH _i of 8.5, 0.05 A, 4.94 min, d _p of 9.24 mm, h of 7.49 cm, Q _air of 9.98 L/min for 50 µg/L). This study clearly showed that the RSM in the EC process was a very suitable method to optimize the operating conditions at the target value of effluent As(III) concentration (10 µg/L) while keeping the operating cost to minimal and maximize the removal efficiency.