Characteristics of Lead Corrosion Scales Formed during Drinking Water Distribution and Their Potential Influence on the Release of Lead and Other Contaminants
Characteristics of Lead Corrosion Scales Formed during Drinking Water Distribution and Their Potential Influence on the Release of Lead and Other Contaminants
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DOI：
10.1021/es101328u
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发表时间：
2010-08-15
影响因子：
11.4
通讯作者：
Herrera, Jose E.
中科院分区：
文献类型：
--
作者：
Kim, Eun Jung;Herrera, Jose E.
饮用水分配系统中使用的铅管腐蚀规模的不稳定目前被认为是部分由铅管提供服务的市政当局面临的一个主要问题，尽管一些铅腐蚀战略已经成功部署，本文重点对加拿大伦敦市饮用水分配系统中铅管内表面形成的腐蚀垢中存在的层进行了全面表征，采用x射线衍射（XRD）、拉曼光谱、傅立叶变换红外（FTIR）光谱对固体腐蚀产物进行了表征。酸消解后，采用电感耦合等离子体（ICP）光谱法对腐蚀垢中积累的有毒元素进行了鉴定。根据XRD结果，大多数样品的铅晶腐蚀相以氢铈矿为主。在腐蚀层的内层中还观察到PbO2和Pb3O4等铅氧化物的存在，这些高氧化铅的存在是由于铅（II）碳酸盐相通过中间的Pb3O4(2Pb(II)O中心点(PbO2)-O-IV相转变为铅（IV）氧化物。除铅腐蚀产物外，在腐蚀垢中还发现了一种无定形的铝硅酸盐相，其浓度在外表层特别高。砷、V、Sb、Cu、Cr等有毒污染物在腐蚀垢中富集，砷的富集与铝的浓度有较强的相关性。
Destabilization of the corrosion scale present in lead pipes used in drinking water distribution systems is currently considered a major problem for municipalities serviced in part by lead pipes Although several lead corrosion strategies have been deployed with success, a clear understanding of the chemistry of corrosion products present in the scale is needed for an effective lead control This contribution focuses on a comprehensive characterization of the layers present in the corrosion scale formed on the inner surfaces of lead pipes used in the drinking water distribution system of the City on London, ON, Canada Solid corrosion products were characterized using X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS) Toxic elements accumulated in the corrosion scale were also identified using inductively coupled plasma (ICP) spectrometry after acid digestion Based on the XRD results, hydrocerussite was identified as the major lead crystalline corrosion phase in most of the pipes sampled, while cerussite was observed as the main crystalline component only in a few cases Lead oxides including PbO2 and Pb3O4 were also observed in the inner layers of the corrosion scale The presence of these highly oxidized lead species is rationalized in terms of the lead(II) carbonate phase transforming into lead(IV) oxide through an intermediate Pb3O4(2Pb(II)O center dot(PbO2)-O-IV) phase. In addition to lead corrosion products, an amorphous aluminosilicate phase was also identified in the corrosion scale Its concentration is particularly high at the outer surface layers. Accumulation of toxic contaminants such as As, V, Sb, Cu, and Cr was observed in the corrosion scales, together with a strong correlation between arsenic accumulation and aluminum concentration.