Arsenic Treatment Using Electrolytic Ferrous Reagent to Replace Bulk Ferric Chloride.

Key Takeaways: As federal maximum contaminant level (MCL) recommendations for arsenic in drinking water are being reviewed, US utilities are preparing for more stringent regulations. If faced with reducing its treated water's arsenic concentration to 5 μg/L, the City of Alamosa, Colo., would need to increase its ferric chloride dose—raising supply, cost, and operational concerns. To avoid these issues, the city explored a new technology that generates a ferrous reagent via an in situ electrolytic process to replace bulk ferric chloride. The electrolytic ferrous reagent removed arsenic to below 5 μg/L, reduced permeate manganese levels, and improved effluent quality with a far lower coagulant dose. [ABSTRACT FROM AUTHOR]