气候变化领域集成服务门户

The United States Environmental Protection Agency (US EPA) will require some U.S. drinking water distribution systems (DWDS) to monitor nonradioactive strontium (Sr2+) in drinking water in 2013. Iron corrosion products from four DWDS were examined to assess the potential for Sr2+ binding and release. Average Sr2+ concentrations in the outermost layer of the corrosion products ranged from 3 to 54 mg kg(-1) and the Sr2+ drinking water concentrations were all <= 0.3 mg L-1. Micro-X-ray adsorption near edge structure spectroscopy and linear combination fitting determined that Sr2+ was principally associated with CaCO3. Sr2+ was also detected as a surface complex associated with alpha-FeOOH. Iron particulates deposited on a filter inside a home had an average Sr2+ concentration of 40.3 mg kg(-1) and the associated drinking water at a tap Was 210 mu g L-1. The data suggest that elevated Sr2+ concentrations may be associated with iron corrosion products that, if disturbed, could increase Sr2+ concentrations above the 0.3 mu g L-1 US EPA reporting threshold. Disassociation of very small particulates could result in drinking water Sr2+ concentrations that exceed the US EPA health reference limit (4.20 mg kg(-1) body weight).