Department of Energy, Environmental, and Chemical Engineering, Campus Box 1180, 1 Brookings Drive, Washington University, St. Louis, Missouri 63130, United States.
Environ Sci Technol. 2010 Dec 1;44(23):8950-6. doi: 10.1021/es102318z. Epub 2010 Nov 3.
Lead(IV) oxide (PbO(2)) is a corrosion product that can develop on lead pipes used for drinking water supply, and its stability can control lead concentrations in tap water. A set of batch experiments were performed to determine the extent of PbO(2) formation as a function of time, pH, the presence of dissolved inorganic carbon (DIC), and free chlorine concentration. Experiments were conducted with four lead(II) compounds that are precursors of PbO(2) formation: dissolved lead(II) chloride, massicot (β-PbO), cerussite (PbCO(3)), and hydrocerussite (Pb(3)(OH)(2)(CO(3))(2)). While PbO(2) formed in the presence and absence of DIC, the presence of DIC accelerated PbO(2) formation and affected the identity of the PbO(2) (scrutinyite vs plattnerite) product. For some conditions, intermediate solids formed that affected the identity of the PbO(2) produced. When no intermediate solids formed, hydrocerussite led to the formation of pure scrutinyite, and lead(II) chloride and massicot led to mixtures of scrutinyite and plattnerite. Based on the experimental results, a conceptual model of lead(IV) oxide formation pathways was proposed.
四氧化铅（PbO(2)）是一种腐蚀产物，可能在用于饮用水供应的铅管上形成，其稳定性可以控制自来水中的铅浓度。进行了一系列批实验，以确定 PbO(2)形成的程度随时间、pH 值、溶解无机碳 (DIC) 的存在和游离氯浓度的变化。实验使用了四种铅(II)化合物作为 PbO(2)形成的前体：溶解的铅(II)氯化物、一氧化铅（β-PbO）、碳酸铅（PbCO(3)）和碱式碳酸铅（Pb(3)(OH)(2)(CO(3))(2)）。虽然 DIC 的存在和不存在都会导致 PbO(2)的形成，但 DIC 的存在加速了 PbO(2)的形成，并影响了 PbO(2)（方铅矿 vs. 板钛矿）产物的形态。对于某些条件，会形成中间固体，从而影响产生的 PbO(2)的形态。当没有中间固体形成时，碱式碳酸铅会导致纯方铅矿的形成，而铅(II)氯化物和一氧化铅则会导致方铅矿和板钛矿的混合物。根据实验结果，提出了四氧化铅形成途径的概念模型。
