University of Ljubljana, Faculty of Chemistry and Chemical Technology, 113 Večna pot, SI-1000 Ljubljana, Slovenia.
University of Ljubljana, Faculty of Chemistry and Chemical Technology, 113 Večna pot, SI-1000 Ljubljana, Slovenia.
Sci Total Environ. 2023 Aug 25;888:164163. doi: 10.1016/j.scitotenv.2023.164163. Epub 2023 May 16.
In this study, we investigated the interactions between titanium dioxide (nTiO) and zinc oxide (nZnO) nanoparticles and polyethylene microplastics (MPs) with respect to their adsorption and subsequent desorption in aquatic media. Adsorption kinetic models revealed rapid adsorption of nZnO compared to nTiO, while nTiO was adsorbed to a greater extent - four times more nTiO (67%) was adsorbed on MPs than nZnO (16%). The low adsorption of nZnO can be explained by the partial dissolution of zinc from nZnO in the form of Zn(II) and/or Zn(II) aqua-hydroxo complexes (e.g. [Zn(OH)], [Zn(OH)], [Zn(OH)]), which were not adsorbed on MPs. Adsorption isotherm models indicated that the adsorption process is controlled by physisorption for both nTiO and nZnO. The desorption of nTiO was low (up to 27%) and not pH dependent, and only nanoparticles were desorbed from the MPs surface. On the other hand, the desorption of nZnO was pH dependent; at a slightly acidic pH (pH = 6), 89% of the adsorbed zinc was desorbed from the MPs surface and the majority were in the form of nanoparticles; at a slightly alkaline pH (pH = 8.3), 72% of the zinc was desorbed, but the majority were in the soluble form of Zn(II) and/or Zn(II) aqua-hydroxo complexes. These results demonstrated the complexity and variability of interactions between MPs and metal engineered nanoparticles and contribute to a better understanding of their fate in the aquatic environment.
在这项研究中，我们研究了二氧化钛（nTiO）和氧化锌（nZnO）纳米颗粒与聚乙烯微塑料（MPs）之间的相互作用，以及它们在水介质中的吸附和随后的解吸。吸附动力学模型表明，nZnO 的吸附速度比 nTiO 快，而 nTiO 的吸附量更大——nTiO（67%）比 nZnO（16%）更多地被吸附在 MPs 上。nZnO 的低吸附量可以用锌从 nZnO 中以 Zn(II)和/或 Zn(II)水合羟络合物（例如 [Zn(OH)]、[Zn(OH)]、[Zn(OH)]）的形式部分溶解来解释，这些物质没有被吸附在 MPs 上。吸附等温线模型表明，对于 nTiO 和 nZnO，吸附过程受物理吸附控制。nTiO 的解吸量很低（最高为 27%）且与 pH 值无关，只有纳米颗粒从 MPs 表面解吸。另一方面，nZnO 的解吸与 pH 值有关；在略酸性 pH 值（pH = 6）下，89%的吸附锌从 MPs 表面解吸，大部分以纳米颗粒的形式存在；在略碱性 pH 值（pH = 8.3）下，72%的锌被解吸，但大部分以 Zn(II)和/或 Zn(II)水合羟络合物的可溶性形式存在。这些结果表明了 MPs 和金属工程纳米颗粒之间相互作用的复杂性和可变性，有助于更好地理解它们在水环境中的命运。
