Office of Research and Development, Drinking Water Management Branch, Center for Environmental Solutions & Emergency Response, Water Infrastructure Division, U.S. Environmental Protection Agency, Cincinnati, Ohio, USA.
Office of Research and Development, Center for Environmental Solutions & Emergency Response, Water Infrastructure Division, Oak Ridge Associated Universities (ORAU) Student Services Contractor to the U.S. Environmental Protection Agency, Cincinnati, Ohio, USA.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2020;55(13):1504-1512. doi: 10.1080/10934529.2020.1810498. Epub 2020 Sep 22.
There is great interest in producing nanoparticles for various applications. The objective of this work was to develop a procedure for reproducibly creating stable lead (Pb) phosphate nanoparticle aqueous suspensions. A stable 5 mg/L Pb-phosphate nanoparticle "stock" suspension was synthesized via chemical precipitation of Pb and orthophosphate in water at pH 7.5 with 4.4 mg soluble PO/L and 7 mg C/L dissolved inorganic carbon. The stock suspension was subsequently diluted to produce stable 0.10 mg/L Pb "challenge" water suspensions without compromising the nanoparticle size, structure, mineralogy and solubility. Specifically, the hexagonal hydroxypyromorphite nanoparticles had an average diameter of 38 nm based on transmission electron microscopy analysis and an associated Pb solubility of 0.001 mg/L. The properties of the stock suspensions were not impacted by further dilutions, and the challenge water suspensions remained stable for 24 hours. In the context of drinking water, a protocol to produce such a stable Pb nanoparticle challenge water suspension would be very useful in evaluating Pb bioavailability, identifying Pb remediation strategies, and testing filter effectiveness to remove Pb from water.
人们对生产各种应用的纳米颗粒非常感兴趣。这项工作的目的是开发一种可重复制备稳定的磷酸铅纳米颗粒水悬浮液的方法。通过在 pH 值为 7.5 的水中用化学沉淀法将 Pb 和正磷酸盐沉淀，在 4.4mg/L 可溶 PO/L 和 7mg/L 溶解无机碳的条件下，合成了稳定的 5mg/L Pb-磷酸盐纳米颗粒“储备”悬浮液。随后将储备悬浮液稀释，以产生稳定的 0.10mg/L Pb“挑战”水悬浮液，而不会影响纳米颗粒的尺寸、结构、矿物学和溶解度。具体来说，基于透射电子显微镜分析，六方羟磷铅矿纳米颗粒的平均直径为 38nm，其 Pb 溶解度为 0.001mg/L。储备悬浮液的性质不受进一步稀释的影响，挑战水悬浮液在 24 小时内保持稳定。在饮用水方面，生产这种稳定的 Pb 纳米颗粒挑战水悬浮液的方案将非常有助于评估 Pb 的生物利用度，确定 Pb 修复策略，并测试过滤效果以去除水中的 Pb。
