AWWA JAW68592

Iron-modified granular activated carbon (GAC) and zero-valent iron (ZVI) have been shown to be effective for arsenic (As) adsorption, but they both have strengths and shortcomings. In this research, GAC and ZVI were combined in an innovative As adsorption system that shows significant potential for removal of As in drinking water systems. Results of rapid small-scale column tests indicated that an optimum combination of GAC and ZVI removed As to meet the US standard of 10 µg/L while providing a cost-effective way of increasing the bed life of GAC. Further studies are needed to determine whether laboratory results can be extended to fullscale application and other water sources. This work represents a promising approach to removing As, especially for water providers that already have GAC systems installed. Rather than installing new processes for As removal, utilities may be able to adapt their current systems to meet the regulatory challenge. Includes 27 references, tables, figures.