Lytle Darren A, White Colin, Nadagouda Mallikarjuna N, Worrall Adam
United States Environmental Protection Agency, ORD, NRMRL, WSWRD, TTEB, Cincinnati, OH 45268, United States.
J Hazard Mater. 2009 Jun 15;165(1-3):1234-8. doi: 10.1016/j.jhazmat.2008.10.058. Epub 2008 Nov 1.
Herein, we show an important transformation of Pb(II) to Pb(IV) in chlorinated water under laboratory conditions. The study results will give an insight toward understanding how corrosion by-products on lead materials found in drinking water distribution systems develop and breakdown with time. The experiments were conducted to elucidate the morphology of lead (IV) oxide mineral transformation from hydrocerussite and its relationship to color change over a period of time. Scanning electron microscopy and transmission electron microscopy were used to describe the surface morphology, shape and size of lead solids. X-ray diffraction (XRD) analysis was performed to determine the mineral structure of lead solids. Solids analysis results were compared over a 14-day period of time to define changes in the crystal structure and morphology of lead solids. XRD analysis results of freshly synthesized lead solids showed that hydrocerussite, [Pb(3)(CO(3))(2)(OH)(2)], was the only lead mineral present. After 14 days, a mixture of cerussite (PbCO(3)) and alpha-PbO(2) and beta-PbO(2) was present. Lead precipitates, i.e. hydrocerussite changed color from white to reddish brown confirming a transformation of the lead phase with time. This was correlated to a change in morphology from flower shaped crystals to hexagonal bars and submicron particles.
在此，我们展示了在实验室条件下，氯化水中铅（II）向铅（IV）的重要转变。研究结果将有助于深入了解饮用水分配系统中铅材料上的腐蚀副产物如何随时间形成和分解。进行这些实验是为了阐明由碳酸铅矿转化而来的二氧化铅矿物的形态及其随时间的颜色变化关系。使用扫描电子显微镜和透射电子显微镜来描述铅固体的表面形态、形状和尺寸。进行X射线衍射（XRD）分析以确定铅固体的矿物结构。在14天的时间内比较固体分析结果，以确定铅固体晶体结构和形态的变化。新合成的铅固体的XRD分析结果表明，碳酸铅矿[Pb(3)(CO(3))(2)(OH)(2)]是唯一存在的铅矿物。14天后，出现了碳酸铅（PbCO(3)）与α-PbO(2)和β-PbO(2)的混合物。铅沉淀物，即碳酸铅矿，颜色从白色变为红棕色，证实了铅相随时间的转变。这与形态从花状晶体变为六边形棒和亚微米颗粒的变化相关。
