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

Abstract

ABSTRACTIn this study, influences of seven process variables such as initial pH (pHi), applied current (i), operating time (tEC), initial As(III) concentration (Co), diameter of Fe ball anode (dp), column height in the electrocoagulation (EC) reactor (h) and airflow rate (Qair) 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 $/m3 at the optimum operating conditions (a pHi of 8.5, 0.05 A, 4.94 min, dp of 9.24 mm, h of 7.49 cm, Qair 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.