Water Resources Research Act Program

Details for Project ID 2009ND186B

Development of GAC-NZVI Adsorbent for Arsenic Removal

Institute: North Dakota
Year Established: 2009 Start Date: 2009-03-01 End Date: 2011-02-01
Total Federal Funds: $20,000 Total Non-Federal Funds: $40,000

Principal Investigators: Wei Lin

Project Summary: The occurrence of arsenic in groundwater is of great concern because arsenic can contribute to skin, bladder, and other cancers. The U.S. Environmental Protection Agency (USEPA) revised its drinking water maximum contaminant level (MCL) for arsenic downwards from 50 g/L to 10 g/L in January, 2001; the World Health Organization (WHO) and European Union also set their recommended or required arsenic limit at 10g/L. Many areas have been identified in the USA with arsenic problems in groundwater. A superfund site, located in parts of Ransom, Richland and Sargent counties, North Dakota, is on the national arsenic pollution map. The arsenic level is approximately 24g/L in all three wells supplying drinking water at Oakes and at around 40 g/L at Devils Lake, North Dakota. MCL dropping from 50 g/L to 10 g/L presented a major challenge for the existing water supply systems to comply with the new regulation, especially the rural small community systems which until recently had few regulation requirements. Some of small communities are attempting to apply for regulatory exemptions due to the high costs associated with meeting the MCL. While exemptions offer temporary cost savings, they do not defend the population from possible negative health impacts. There is an urgent need to develop safe and affordable technologies to meet the new safe drinking water standard for the rural communities in North Dakota. Adsorption technology is considered an effective and efficient method to control the odor/taste and remove contaminants from drinking water. Among available adsorbents, activated carbon is widely used due to its commercially availability and excellent properties: huge specific surface area and advanced pore structure. Many of research found adsorption capacity for arsenic can be improved significantly after granular activated carbon (GAC) is impregnated with iron. It is hypothesized that GAC-NZVI could be synthesized with desired amounts of NZVI, which are stable and reactive to arsenic removal from drinking water. In this proposed study, GAC-Iron will be converted to GAC-NZVI and arsenic adsorption studies (batch and column) will be carried out. The proposed research is to synthesize GAC-NZVI with desired content of nano iron which are stable and highly reactive. GAC-NZVI could be a promising adsorbent to treat trace arsenic in drinking water by inheriting advantages from GAC and NZVI while avoiding their drawbacks.