Department of Environmental Science, Zhejiang University, Hangzhou 310058, China.
Department of Environmental Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Zhejiang University, Hangzhou 310058, China.
Environ Pollut. 2016 Apr;211:132-40. doi: 10.1016/j.envpol.2015.12.041. Epub 2015 Dec 30.
Most studies on the behavior and toxicity of engineered nanoparticles (NPs) have been conducted in artificial water with well-controlled conditions, which are dramatically different from natural waters with complex compositions. To better understand the fate and toxicity of NPs in the natural water environment, physicochemical transformations of four NPs (TiO2, ZnO, Ag, and carbon nanotubes (CNTs)) and their toxicities towards a unicellular green alga (Chlorella pyrenoidosa) in four fresh water and one seawater sample were investigated. Results indicated that water chemistry had profound effects on aggregation, dissolution, and algal toxicity of the NPs. The strongest homoaggregation of the NPs was associated with the highest ionic strength, but no obvious correlation was observed between the homoaggregation of NPs and pH or dissolved organic matter content of the water samples. The greatest dissolution of ZnO NPs also occurred in seawater with the highest ionic strength, while the dissolution of Ag NPs varied differently from ZnO NPs. The released Zn(2+) and especially Ag(+) mainly accounted for the algal toxicity of ZnO and Ag NPs, respectively. The NP-cell heteroagglomeration occurred generally for CNTs and Ag NPs, which contributed to the observed nanotoxicity. However, there was no significant correlation between the observed nanotoxicity and the type of NP or the water chemistry. It was thus concluded that the physicochemical transformations and algal toxicities of NPs in the natural water samples were caused by the combined effects of complex water quality parameters rather than any single influencing factor alone. These results will increase our knowledge on the fate and effects of NPs in the aquatic environment.
大多数关于工程纳米粒子（NPs）的行为和毒性的研究都是在人为控制条件下的人工水中进行的，这与具有复杂成分的天然水有很大的不同。为了更好地了解 NPs 在自然水环境中的归宿和毒性，本研究考察了四种 NPs（TiO2、ZnO、Ag 和碳纳米管（CNTs））在四种淡水和一种海水中的理化转化及其对单细胞绿藻（Chlorella pyrenoidosa）的毒性。结果表明，水化学对 NPs 的聚集、溶解和藻类毒性有深远的影响。NP 最强的同源聚集与最高的离子强度有关，但 NP 的同源聚集与水样品的 pH 值或溶解有机物含量之间没有明显的相关性。ZnO NPs 的最大溶解也发生在离子强度最高的海水中，而 Ag NPs 的溶解则与 ZnO NPs 不同。释放的 Zn(2+)和特别是 Ag(+)主要导致 ZnO 和 Ag NPs 的藻类毒性，NP-细胞异质凝聚普遍发生在 CNTs 和 Ag NPs 上，这导致了观察到的纳米毒性。然而，观察到的纳米毒性与 NP 的类型或水化学之间没有显著的相关性。因此，我们得出结论，天然水样中 NPs 的理化转化和藻类毒性是由复杂水质参数的综合影响造成的，而不是任何单一因素的影响。这些结果将增加我们对 NPs 在水生环境中的归宿和效应的认识。
