National Research Council, US Environmental Protection Agency, Office of Research and Development, Narragansett, Rhode Island; State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China.
Environ Toxicol Chem. 2014 May;33(5):1023-9. doi: 10.1002/etc.2529. Epub 2014 Mar 12.
The behavior and fate of nanoparticles (NPs) in the marine environment are largely unknown and potentially have important environmental and human health implications. The aggregation and fate of NPs in the marine environment are greatly influenced by their interactions with seawater and dissolved organic carbon (DOC). In the present study, the stability and aggregation of 30-nm-diameter silver nanoparticles (AgNPs) capped with citrate and polyvinylpyrrolidone (PVP; AgNP-citrate and AgNP-PVP) and 21-nm-diameter titanium dioxide (TiO(2)) NPs as affected by seawater salinity and DOC were investigated by measuring hydrodynamic diameters and zeta potentials. The added DOC (in humic acid form) stabilized the 3 types of NPs when the seawater salinities were ≤5 parts per thousand (ppt), but the stabilizing effect of DOC was reduced by a higher salinity (e.g., 30 ppt). In addition, AgNP-PVP was more stable than AgNP-citrate in seawater, indicating that surface capping agents and stabilization mechanisms govern the stability and aggregation of NPs. Statistical analysis showed that salinity is the most dominant influence on the stability and aggregation of AgNPs and TiO(2) NPs, followed by DOC. These findings expand our knowledge on the behavior of AgNPs and TiO2 NPs in seawater and indicate that the fate of these NPs will be primarily to aggregate in the water column, precipitate, and accumulate in sediments following release into the marine environment.
纳米颗粒（NPs）在海洋环境中的行为和归宿在很大程度上是未知的，并且可能对环境和人类健康产生重要影响。纳米颗粒在海洋环境中的聚集和归宿受其与海水和溶解有机碳（DOC）相互作用的强烈影响。在本研究中，通过测量水动力直径和zeta 电位，研究了 30nm 直径的银纳米颗粒（AgNPs），其表面被柠檬酸和聚乙烯吡咯烷酮（PVP；AgNP-柠檬酸和 AgNP-PVP）覆盖，以及 21nm 直径的二氧化钛（TiO(2)) NPs 在海水盐度和 DOC 影响下的稳定性和聚集。当海水盐度≤5‰时，添加的 DOC（以腐殖酸形式存在）稳定了 3 种类型的 NPs，但当盐度较高（例如 30‰）时，DOC 的稳定作用降低。此外，AgNP-PVP 在海水中比 AgNP-柠檬酸更稳定，表明表面覆盖剂和稳定机制控制着 NPs 的稳定性和聚集。统计分析表明，盐度是影响 AgNPs 和 TiO(2) NPs 稳定性和聚集的最主要因素，其次是 DOC。这些发现扩展了我们对 AgNPs 和 TiO2 NPs 在海水中行为的认识，并表明这些 NPs 的命运主要是在释放到海洋环境后在水柱中聚集、沉淀和在沉积物中积累。
