The combined pollution induced by microplastics (MPs) and other pollutants, such as nanomaterials, has received increasing attention. The interaction between MPs and silver nanoparticles (AgNPs) may affect both their behaviors in natural environments, however, knowledge on these effects remains limited. In this study, AgNPs and three common MPs, polypropylene (PP), polyethylene (PE), and polystyrene (PS), were co-exposed to natural freshwater and brackish water to investigate the interaction between MPs and AgNPs in natural surface water. The results showed that the environmental behaviour of AgNPs in natural freshwater and brackish water is first of all affected by water chemistry and only in second instance affected by MPs. In natural freshwater, AgNPs remained stable largely dominated by dissolved organic matter (DOM), parts of which were subsequently captured by three MPs in the form of single particles without significant difference. In contrast, both ionic strength and DOM contributed to the aggregation of AgNPs in natural brackish water. PE and PP captured a small amount of AgNPs in the form of aggregates in natural brackish water, while the majority of AgNP aggregates were trapped by PS in natural brackish water. Therefore, both water chemistry and MPs types were found to play crucial roles in the interaction between MPs and AgNPs. These observations also revealed that MPs could serve as carriers for AgNP transport and advance the current understanding of combined pollution between MPs and engineered nanomaterials in natural aquatic environments.

由微塑料 (MPs) 和其他污染物（如纳米材料）引起的复合污染越来越受到关注。MPs 和银纳米粒子 (AgNPs) 之间的相互作用可能会影响它们在自然环境中的行为，但是，关于这些影响的知识仍然有限。在这项研究中，AgNPs 和三种常见的 MPs，聚丙烯 (PP)、聚乙烯 (PE) 和聚苯乙烯 (PS)，共同暴露于天然淡水和微咸水中，以研究 MPs 和 AgNPs 在天然地表水中的相互作用。结果表明，AgNPs 在天然淡水和微咸水中的环境行为首先受水化学的影响，其次才受 MPs 的影响。在天然淡水中，AgNPs 保持稳定，主要由溶解有机物 (DOM) 主导，其中的一部分随后被三个 MP 以单个粒子的形式捕获，没有显着差异。相比之下，离子强度和 DOM 都有助于 AgNPs 在天然微咸水中的聚集。PE和PP在天然苦咸水中以聚集体的形式捕获了少量AgNPs，而大多数AgNP聚集体在天然苦咸水中被PS捕获。因此，发现水化学和 MPs 类型在 MPs 和 AgNPs 之间的相互作用中起着至关重要的作用。这些观察结果还表明，MPs 可以作为 AgNP 运输的载体，并促进当前对 MPs 与天然水生环境中工程纳米材料之间复合污染的理解。离子强度和 DOM 都有助于 AgNPs 在天然微咸水中的聚集。PE和PP在天然苦咸水中以聚集体的形式捕获了少量AgNPs，而大多数AgNP聚集体在天然苦咸水中被PS捕获。因此，发现水化学和 MPs 类型在 MPs 和 AgNPs 之间的相互作用中起着至关重要的作用。这些观察结果还表明，MPs 可以作为 AgNP 运输的载体，并促进当前对 MPs 与天然水生环境中工程纳米材料之间复合污染的理解。离子强度和 DOM 都有助于 AgNPs 在天然微咸水中的聚集。PE和PP在天然苦咸水中以聚集体的形式捕获了少量AgNPs，而大多数AgNP聚集体在天然苦咸水中被PS捕获。因此，发现水化学和 MPs 类型在 MPs 和 AgNPs 之间的相互作用中起着至关重要的作用。这些观察结果还表明，MPs 可以作为 AgNP 运输的载体，并促进当前对 MPs 与天然水生环境中工程纳米材料之间复合污染的理解。而大多数 AgNP 聚集体在天然微咸水中被 PS 捕获。因此，发现水化学和 MPs 类型在 MPs 和 AgNPs 之间的相互作用中起着至关重要的作用。这些观察结果还表明，MPs 可以作为 AgNP 运输的载体，并促进当前对 MPs 与天然水生环境中工程纳米材料之间复合污染的理解。而大多数 AgNP 聚集体在天然微咸水中被 PS 捕获。因此，发现水化学和 MPs 类型在 MPs 和 AgNPs 之间的相互作用中起着至关重要的作用。这些观察结果还表明，MPs 可以作为 AgNP 运输的载体，并促进当前对 MPs 与天然水生环境中工程纳米材料之间复合污染的理解。