Nanoscale Chemical Imaging of Nanoparticles under Real-World Wastewater Treatment Conditions
Nanoscale Chemical Imaging of Nanoparticles under Real-World Wastewater Treatment Conditions
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DOI：
10.1002/adsu.202100023
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发表时间：
2021-05-05
影响因子：
7.1
通讯作者：
Porter, Alexandra E.
中科院分区：
文献类型：
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作者：
Gomez-Gonzalez, Miguel A.;Koronfel, Mohamed A.;Porter, Alexandra E.
了解废水处理厂内纳米材料的转化是更好地预测其对环境的潜在影响的重要一步。在这里，空间分辨，原位纳米x射线荧光显微镜应用于直接观察纳米尺度的溶解，形态，以及在复杂的“现实世界”条件下单个和聚集的ZnO纳米棒的化学演化：从城市污水系统收集的进水和初级污泥。分离的ZnO纳米棒在进水中仅1小时就完全转化为ZnS，但较大的ZnO纳米棒在3小时后仅部分转化，ZnS和zn -磷酸(Zn-3（PO4)(2)）物质的贡献很小。在初级污泥中培养3小时，观察到ZnO纳米棒的团聚体向混合ZnS转变，Zn吸附在铁氧氢氧化物上，并且Zn-3(PO4)(2)相的贡献很大。离散的、孤立的ZnO区域以前所未有的空间分辨率成像，揭示了它们向Zn-3（PO4）转变的初期(2)。通过转变成低溶相混合物的钝化可能会影响这些纳米材料随后的生物反应性。这项工作强调了在高度复杂的非均质半固体基质中对纳米颗粒混合物进行纳米级化学成像的重要性，这有助于预测其对处理过程的影响，以及释放后的潜在环境毒性。
Understanding nanomaterial transformations within wastewater treatment plants is an important step to better predict their potential impact on the environment. Here, spatially resolved, in situ nano-X-ray fluorescence microscopy is applied to directly observe nanometer-scale dissolution, morphological, and chemical evolution of individual and aggregated ZnO nanorods in complex "real-world" conditions: influent water and primary sludge collected from a municipal wastewater system. A complete transformation of isolated ZnO nanorods into ZnS occurs after only 1 hour in influent water, but larger aggregates of the ZnO nanorods transform only partially, with small contributions of ZnS and Zn-phosphate (Zn-3(PO4)(2)) species, after 3 hours. Transformation of aggregates of the ZnO nanorods toward mixed ZnS, Zn adsorbed to Fe-oxyhydroxides, and a large contribution of Zn-3(PO4)(2) phases are observed during their incubation in primary sludge for 3 hours. Discrete, isolated ZnO regions are imaged with unprecedented spatial resolution, revealing their incipient transformation toward Zn-3(PO4)(2). Passivation by transformation(s) into mixtures of less soluble phases may influence the subsequent bioreactivity of these nanomaterials. This work emphasizes the importance of imaging the nanoscale chemistry of mixtures of nanoparticles in highly complex, heterogeneous semi-solid matrices for improved prediction of their impacts on treatment processes, and potential environmental toxicity following release.