Department of Environmental Science, College of Environmental Science and Engineering, Tongji University, State Key Laboratory of Pollution Control and Resources Reuse, Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
School of Medicine, Tongji University, Shanghai 200065, China.
J Environ Sci (China). 2025 Feb;148:541-552. doi: 10.1016/j.jes.2024.01.029. Epub 2024 Feb 10.
The ocean serves as a repository for various types of artificial nanoparticles. Nanoplastics (NPs) and nano zinc oxide (nZnO), which are frequently employed in personal care products and food packaging materials, are likely simultaneously released and eventually into the ocean with surface runoff. Therefore, their mutual influence and shared destiny in marine environment cannot be ignored. This study examined how nanomaterials interacted and transported through sea sand in various salinity conditions. Results showed that NPs remained dispersed in brine, while nZnO formed homoaggregates. In seawater of 35 practical salinity units (PSU), nZnO formed heteroaggregates with NPs, inhibiting NPs mobility and decreasing the recovered mass percentage (M) from 24.52% to 12.65%. In 3.5 PSU brackish water, nZnO did not significantly aggregate with NPs, and thus barely affected their mobility. However, NPs greatly enhanced nZnO transport with M increasing from 14.20% to 25.08%, attributed to the carrier effect of higher mobility NPs. Cotransport from brackish water to seawater was simulated in salinity change experiments and revealed a critical salinity threshold of 10.4 PSU, below which the mobility of NPs was not affected by coexisting nZnO and above which nZnO strongly inhibited NP transport. This study highlights the importance of considering the mutual influence and shared destiny of artificial nanoparticles in the marine environment and how their interaction and cotransport are dependent on changes in seawater salinity.
海洋是各种类型的人工纳米粒子的储存库。纳米塑料（NPs）和纳米氧化锌（nZnO）常用于个人护理产品和食品包装材料，很可能随着地表径流同时释放并最终进入海洋。因此，它们在海洋环境中的相互影响和共同命运不容忽视。本研究探讨了纳米材料在不同盐度条件下如何通过海砂相互作用和迁移。结果表明，NPs 在盐水中保持分散状态，而 nZnO 则形成同聚体。在 35 个实际盐度单位（PSU）的海水中，nZnO 与 NPs 形成异质聚集体，抑制了 NPs 的迁移性，使回收质量百分比（M）从 24.52%降至 12.65%。在 3.5 PSU 的咸水中，nZnO 与 NPs 没有明显聚集，因此对其迁移性影响不大。然而，NPs 极大地增强了 nZnO 的传输，M 值从 14.20%增加到 25.08%，这归因于具有更高迁移性的 NPs 的载体效应。在盐度变化实验中模拟了从咸水到海水的共输运，并揭示了 10.4 PSU 的临界盐度阈值，低于该阈值时，共存的 nZnO 不会影响 NPs 的迁移性，而高于该阈值时，nZnO 会强烈抑制 NP 传输。本研究强调了在海洋环境中考虑人工纳米粒子的相互影响和共同命运的重要性，以及它们的相互作用和共输运如何依赖于海水盐度的变化。
