An empirical model for treatment of arsenic contaminated underground water by electrocoagulation process employing a bipolar cell configuration with continuous flow.

Arsenic (As) was removed electrochemically from underground water (GW) by electrocoagulation (EC) process employing a bipolar cell configuration with continuous flow using iron electrodes. A kinetic model derived from the Lagergren equation was applied to specify the kinetics of the arsenic removal reaction. Elucidation of the effect of the liquid flow rate on the treatment time and on the simulation results of the model was achieved. The results showed that treatment times decreased from 10.50 min to 0.75 min as the flow rate decreased from 3.500 to 0.875 L min(-1) and the current density varied from 15 to 45 A m(-2) respectively. The used sorption kinetic model successfully describes the arsenic removal by this process. The coefficients of determination were found to be very high in all cases (R(2)>0.99) indicating a good fit of the experimental data to Lagergren model.

Energy and electrode consumption analysis of electrocoagulation for the removal of arsenic from underground water.

A systematic study of the effect of design and operation conditions of an electrochemical reactor on the treatment time for arsenic (As) electro-removal from underground water (GW) was carried out to analyse the energy and electrode consumption. The effects of four factors--current density, interelectrode distance, electrode area-volume ratio, and liquid motion driving mode--were evaluated. The response variables were the energy and the electrode consumption and the treatment time to reduce the GW residual As concentration to 10 microg L(-1), which is the maximum contaminant level (MCL) established by the World Health Organization (WHO) in drinking water. The results obtained in this study showed that the factor that had the greatest effect on most of the response variables was the liquid motion driving mode. The best residence time was 20s, which favoured low energy consumption (58.78 Wh m(-3)) and low electrode material loss (9.59 g m(-3)).