Integration of zero valent iron sand beds into biological treatment systems for uranium removal from drinking water wells in rural Canada

Abstract

The current work examines the pilot-scale activities required to utilize a zero valent iron (ZVI) sand bed, incorporated into a biological drinking water treatment system, to remove contaminants, particularly uranium (U) from a rural Canadian water well. Available technologies for U removal tend to be unsuitable for many small communities which lack resources. While ZVI has been acknowledged to be an attractive option, the technology has not achieved successful full-scale implementation. This work included a small-scale column and onsite pilot study. A loading capacity of 5962 mg U/kg ZVI was determined by column study. A ZVI sand filter integrated into a biological pilot system reduced contaminants to within acceptable standards, meeting our objectives including reducing U to <4 μg/L. Disposal of residuals (solid and liquid) was examined and the process was determined to be economically feasible and efficient.