Department of Civil and Environmental Engineering, University of Washington, Seattle, WA 98105-2700, United States.
Water Res. 2011 Nov 1;45(17):5553-63. doi: 10.1016/j.watres.2011.08.017. Epub 2011 Aug 18.
Sequential extractions utilizing the modified Tessier scheme (Krishnamurti et al., 1995) and measurements of soluble and particulate metal released from suspended solids were used in this study to determine the speciation and mobility of inorganic contaminants (As, Cr, V, U, Cd, Ni, and Mn) found in corrosion scales and particles mobilized during hydraulic flushing events. Arsenic, chromium and vanadium are primarily associated with the mobilization-resistant fraction that is resistant to all eluents used in this study and also bound in highly stable crystalline iron oxides. Very low concentrations of these elements were released in resuspension experiments. X-ray absorbance measurements demonstrated that arsenic in the sample with the highest As concentration was dominated by As(V) bound by iron oxides. Significant fractions of uranium and cadmium were associated with carbonate solids. Nickel and manganese were determined to be more mobile and significantly associated with organic fractions. This may indicate that biofilms and natural organic matter in the drinking water distributions systems play an important role in the accumulation and release of these inorganic contaminants.
本研究采用改进的 Tessier 方案（Krishnamurti 等人，1995 年）进行连续提取，并测量悬浮固体释放的可溶性和颗粒态金属，以确定在水力冲洗事件中迁移的腐蚀层和颗粒中发现的无机污染物（砷、铬、钒、铀、镉、镍和锰）的形态和迁移性。砷、铬和钒主要与抗迁移性部分相关，该部分抗所有本研究中使用的洗脱剂，并且也与高度稳定的结晶氧化铁结合。在再悬浮实验中，这些元素的释放浓度非常低。X 射线吸收测量表明，在砷浓度最高的样品中，砷主要由氧化铁结合的 As(V) 组成。铀和镉的很大一部分与碳酸盐固体有关。镍和锰被确定为更具迁移性，并且与有机部分密切相关。这可能表明饮用水分配系统中的生物膜和天然有机物在这些无机污染物的积累和释放中发挥了重要作用。
