Effect of Aluminum on Lead Release to Drinking Water from Scales of Corrosion Products
Effect of Aluminum on Lead Release to Drinking Water from Scales of Corrosion Products
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DOI：
10.1021/acs.est.0c00738
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发表时间：
2020-05-19
影响因子：
11.4
通讯作者：
Giammar, Daniel E.
中科院分区：
文献类型：
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作者：
Li, Guiwei;Bae, Yeunook;Giammar, Daniel E.
铅管上铝垢的出现是很常见的。本研究旨在确定影响氧化铅表面Al积累的因素，并确定Al的存在是否影响铅从腐蚀产物向水中的释放。在添加和不添加磷酸盐作为缓蚀剂的情况下，监测了铝的积累和铅的释放。将带腐蚀鳞片的Pb片暴露于氯化水中198 d，观察Al的积累和Pb的释放。Pb腐蚀产物促进了Al的积累，但磷酸盐的加入抑制了Al的积累。在研究期间，当不含磷酸盐时，Al沉积物的形成不影响Pb的释放。在无al体系中，加入1.0 mg/L的磷酸盐（如P）可使溶解Pb浓度降至1.0 μ g/L以下。在含有200 μ g/L Al的体系中，磷酸盐对Pb控制作用的出现延迟，溶解Pb浓度下降，但稳定在较高的值（10-12 μ g/L）。磷酸己烷(Ca2Pb3（PO4)(3)Cl）在所有含磷酸盐体系中都能生成，PbO2的生成不依赖于磷酸盐的添加。Al对Pb释放的影响可能与其对复合材料表面含Pb矿物组成和形态的影响有关。实验室研究在模拟真实铅服务管线的所有条件方面存在不可避免的局限性，但该研究仍然强调了在设计铅腐蚀控制策略时考虑Al影响的重要性。
The occurrence of aluminum in scales on lead pipes is common. This study aimed to identify factors that influence Al accumulation on oxidized lead surfaces and to determine whether the presence of Al impacts Pb release from corrosion products to water. Al accumulation and Pb release were monitored both with and without the addition of phosphate as a corrosion inhibitor. Pb coupons with corrosion scales were exposed to chlorinated water for up to 198 days to investigate Al accumulation and Pb release. Al accumulation was facilitated by Pb corrosion products, but its accumulation was inhibited by phosphate addition. During the study period, the formation of Al deposits did not affect Pb release when phosphate was absent. In an Al-free system, the addition of 1.0 mg/L phosphate (as P) lowered the dissolved Pb concentration below 1.0 mu g/L. In a system containing 200 mu g/L Al, the emergence of phosphate's effect on Pb control was delayed, and the dissolved Pb concentration decreased but stabilized at a higher value (10-12 mu g/L) than in the Al-free system. Phosphohedyphane (Ca2Pb3(PO4)(3)Cl) was formed in all phosphate-containing systems, and PbO2 was formed independent of phosphate addition. The effect of Al on Pb release was probably related to its influence on the composition and morphology of Pb-containing minerals on coupon surfaces. The laboratory study has unavoidable limitations in its ability to simulate all conditions in real lead service lines, but this study still highlights the importance of considering the influence of Al when designing Pb corrosion control strategies.