Arsenic removal from groundwater by horizontal-flow continuous electrocoagulation (EC) as a standalone process

In this study, laboratory scale experiments were conducted with the horizontal continuous-flow EC reactor as a standalone technology with the capacity of 300 L/day with iron (Fe) plate bipolar electrodes to assess its efficiency in the removal of arsenic from raw groundwater without pre- and post-treatment pH modification of groundwater. The optimum EC reactor operating conditions were determined to be current density of 1.98 A/m2, charge loading of 54 C/L, flow rate of 12 L/h. The EC reactor was able to remove 96% of arsenic from raw groundwater and met respective World Health Organization (WHO) guideline value of 10 μg As/L within the 4 h experimental runs. The Fe electrode polarity change at 30 min successfully controlled passivation of Fe electrodes and enabled a steady reactor operation with the high As removal efficiency. Residual Fe concentration in treated groundwater was in the range 0.17 ± 0.07 mg/L and met WHO guideline value for drinking water. The preliminary estimated operating cost at the optimum operating conditions was 0.0135 €/m3.