Removal of arsenic from drinking water by batch and continuous electrocoagulation processes using hybrid Al‐Fe plate electrodes

Removals of arsenic from drinking water by electrocoagulation (EC) process using six different combinations of hybrid electrodes (Al‐Fe), and Al‐Al or Fe‐Fe electrodes as all anodes and cathodes in a batch mode were evaluated. The removal process with monopolar series mode at optimum operating conditions (2.50 A/m 2 , 150 µg/L, and pH 7.0) indicated that Fe‐Al‐Al‐Fe (anode‐cathode‐anode‐cathode) hybrid plate electrode pairs were the most efficient choice in terms of arsenic removal efficiency (96% in 1 min) and operating cost (0.00202 €/m 3 ). The arsenic removal from drinking water by continuous EC (CEC) process using Fe‐Al‐Al‐Fe hybrid plate electrode pairs was also studied with respect to flow rates and initial arsenic concentrations. The effluent arsenic concentration of ≤10 µg/L in the CEC process was achieved at 3 min for 0.05 L/min (5.9 µg/L), 8 min for 0.10 L/min (6.3 µg/L), and 20 min for 0.20 L/min (8.4 µg/L), respectively. Amounts of the sludge and operating costs in the CEC process with respect to some experimental parameters such as operating time (3–20 min) and flow rate (0.05–0.20 L/min) at 150 µg/L were determined as 0.0095–0.025 kg/m 3 and 0.009–0.060 €/m 3 . © 2013 American Institute of Chemical Engineers Environ Prog, 33: 131–140, 2014