Institute of Plasma Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China; CAS Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Anhui Province Key Laboratory of Environmental Toxicology and Pollution Control Technology, HFIPS, Chinese Academy of Sciences, Hefei 230031, China.
CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern Mechanics, University of Science and Technology of China, Hefei 230027, China.
Water Res. 2022 Sep 1;223:119030. doi: 10.1016/j.watres.2022.119030. Epub 2022 Aug 29.
The environmental transformation of nanomaterials will have a significant impact on their ecotoxicity. Sulfidation process is one of the most important transformation processes in the aquatic environment. Although the sulfidation of ZnO nanoparticles (ZnO NPs) has been previously reported, the transformation characteristics and the relationship between the transformation process and toxicity mechanism to aquatic organisms, especially microalgae, require further study. Therefore, we systematically investigated the transformation properties of ZnO NPs in sulfur-containing water and its impact on the toxicity to microalgae. The results showed that the transformation products of ZnO NPs mainly contained ZnS nanoparticles, and their contents increased with the increase of sulfur-zinc molar ratio in the aqueous solution. After the first week of treatment, the sulfidized ZnO NPs showed less toxicity to microalgae than the pristine ZnO NPs, and interestingly, they exhibited higher toxicity over time. The zinc ions and transformation products played a major role in different treatment periods, resulting in different toxicity. The results of photosynthetic pigments, photosynthetic efficiency, and the relative electron transport rates indicated that the sulfidation process of ZnO NPs had a remarkable influence on algal photosynthesis. These newly acquired results will help us explore the transformation characteristics of ZnO NPs and reasonably assess their potential risks in the aquatic environment.
纳米材料的环境转化将对其生态毒性产生重大影响。硫化过程是水环境中最重要的转化过程之一。虽然已经有报道称氧化锌纳米粒子（ZnO NPs）发生了硫化，但硫化过程的转化特性以及与水生生物（尤其是微藻）毒性机制之间的关系仍需要进一步研究。因此，我们系统地研究了 ZnO NPs 在含硫水中的转化特性及其对微藻毒性的影响。结果表明，ZnO NPs 的转化产物主要为 ZnS 纳米粒子，且其含量随水溶液中硫锌摩尔比的增加而增加。在处理的第一周，硫化 ZnO NPs 对微藻的毒性小于原始 ZnO NPs，而且有趣的是，随着时间的推移，其毒性逐渐增加。锌离子和转化产物在不同的处理阶段起主要作用，导致毒性不同。光合色素、光合作用效率和相对电子传递率的结果表明，ZnO NPs 的硫化过程对藻类光合作用有显著影响。这些新获得的结果将有助于我们探索 ZnO NPs 的转化特性，并合理评估其在水生态环境中的潜在风险。
