Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel.
Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel.
Sci Total Environ. 2018 Jan 1;610-611:1083-1091. doi: 10.1016/j.scitotenv.2017.08.170. Epub 2017 Aug 30.
As a consequence of their growing use in electronic and industrial products, increasing amounts of technology critical elements (TCEs) are being released to the environment. Currently little is known about the fate of many of these elements. Initial research on their potential environmental impact identifies TCEs as emerging contaminants. TCE movement in the environment is often governed by water systems. Research on "natural" waters so far demonstrates that TCEs tend to be associated with suspended particulate matter (SPM), which influences TCE aqueous concentrations (here: concentration of TCEs in dissolved form and attached to SPM) and transport. However, the relative potential of different types of SPM to interact with TCEs is unknown. Here we examine the potential of various types of particulate matter, namely different nanoparticles (NPs; AlO SiO, CeO, ZnO, montmorillonite, Ag, Au and carbon dots) and humic acid (HA), to impact TCE aqueous concentrations in aqueous solutions with soil and sand, and thus influence TCE transport in soil-water environments. We show that a combination of NPs and HA, and not NPs or HA individually, increases the aqueous concentrations of TCEs in soil solutions, for all tested NPs regardless of their type. TCEs retained on SPM, however, settle with time. In solutions with sand, HA alone is as influential as NPs+HA in keeping TCEs in the aqueous phase. Among NPs, Ag-NPs and Au-NPs demonstrate the highest potential for TCE transport. These results suggest that in natural soil-water environments, once TCEs are retained by soil, their partitioning to the aqueous phase by through-flowing water is unlikely. However, if TCEs are introduced to soil-water environments as part of solutions rich in NPs and HA, it is likely that NP and HA combinations can increase TCE stability in the aqueous phase and prevent their retention on soil and sand, thus facilitating TCE transport.
由于它们在电子和工业产品中的使用越来越多，越来越多的关键技术元素（TCEs）被释放到环境中。目前，人们对其中许多元素的命运知之甚少。对其潜在环境影响的初步研究将 TCEs 确定为新兴污染物。TCE 在环境中的迁移通常受水系控制。对“天然”水的研究表明，TCEs 往往与悬浮颗粒物（SPM）有关，这影响了 TCE 的水相浓度（此处：TCEs 以溶解形式和附着在 SPM 上的浓度）和迁移。然而，不同类型的 SPM 与 TCEs 相互作用的相对潜力尚不清楚。在这里，我们研究了各种类型的颗粒物，即不同的纳米颗粒（NPs；AlO、SiO、CeO、ZnO、蒙脱石、Ag、Au 和碳点）和腐殖酸（HA），对土壤和沙水中 TCE 水相浓度的潜在影响，从而影响土壤-水中 TCE 的迁移。我们表明，NPs 和 HA 的组合，而不是单独的 NPs 或 HA，会增加土壤溶液中 TCE 的水相浓度，对于所有测试的 NPs 都是如此，无论其类型如何。然而，保留在 SPM 上的 TCEs 会随着时间的推移而沉降。在含有沙子的溶液中，HA 单独作用与 NPs+HA 一样，可使 TCE 保留在水相中。在 NPs 中，Ag-NPs 和 Au-NPs 对 TCE 迁移的潜力最大。这些结果表明，在天然土壤-水环境中，一旦 TCEs 被土壤截留，通过水流进入水相的分配就不太可能发生。然而，如果 TCEs 作为富含 NPs 和 HA 的溶液引入到土壤-水环境中，那么 NPs 和 HA 的组合很可能会增加 TCE 在水相中的稳定性，并防止其在土壤和沙子上的保留，从而促进 TCE 的迁移。
