Treatment of Arsenic-Contaminated Industrial Wastewaters

Arsenic in industrial wastewater effluents is attracting greater regulatory attention. Depending on factors such as total maximum daily loads (TMDLs), the National Pollutant Discharge Elimination System (NPDES) discharge permit levels for arsenic may even be less than the drinking water standard of 10 μg/L. One of the industries affected by stringent arsenic discharge limits is coal-fired power generation. Fly ash from coal combustion often contain significant amounts of arsenic, and when sluice water used to convey the fly ash is discharged to surface water, it can contain a significant concentration of soluble arsenic. This paper describes the results of a desktop and pilot study conducted to evaluate the removal of arsenic from an industrial wastewater discharge in the northeastern United States that is subject to a stringent monthly average arsenic discharge limit of 4 μg/L (6 μg/L daily maximum).