Despite continuous research on microplastics (MPs), studies exploring the complexity of interaction between MPs and other aqueous constituents in multi-solute systems are scarce. In this study, the uptake and release of nanoceria (CeNPs) by various polystyrene MPs (PSMPs) were investigated. Results showed that PSMPs in the presence of heavy metals (HMs) exhibited a substantially higher sorption affinity for isotropic charged CeNPs than PSMPs alone; this enhanced affinity was attributed to the formation of PSMP-HM-CeNP complexes. FE-SEM imaging reaffirmed that CeNP clusters adhered to PSMP surfaces in the presence of HMs. Such attachment varied dependent on valence state, atomic size of coexisting metal cations, surface texture, and functionalities of MPs. The HM-mediated complex formation on PSMP particles was suppressed at higher ionic strength because of competitive sorption and double-layer compression. Subsequent release of MP-adhered CeNPs and HMs varied significantly between aquatic media and various simulated digestive fluids, verifying the crucial role of MPs for transfer of engineered nanoparticles (ENPs) from natural environments into biota via ingestion of MPs and trophic transfer. Our results highlight the enhanced potential for MPs to accumulate and to transport ENPs when metallic contaminants are present, which adds to the current understanding of the environmental fate and adverse effects of MPs along with various waterborne contaminants in actual environments.

尽管对微塑料 (MPs) 的研究不断，但探索微塑料与多溶质系统中其他水性成分之间相互作用的复杂性的研究很少。在这项研究中，研究了各种聚苯乙烯 MPs (PSMPs) 对纳米氧化铈 (CeNPs) 的吸收和释放。结果表明，与单独的 PSMPs 相比，在重金属 (HMs) 存在下，PSMPs 对各向同性带电 CeNPs 表现出更高的吸附亲和力；这种增强的亲和力归因于 PSMP-HM-CeNP 复合物的形成。FE-SEM 成像再次证实，在 HMs 存在的情况下，CeNP 簇粘附到 PSMP 表面。这种附着取决于价态、共存金属阳离子的原子大小、表面纹理和 MP 的功能。由于竞争性吸附和双层压缩，在较高离子强度下，PSMP 颗粒上 HM 介导的复合物形成受到抑制。随后释放的 MP 粘附的 CeNPs 和 HMs 在水介质和各种模拟消化液之间显着不同，验证了 MPs 通过摄入 MPs 和营养转移将工程纳米粒子 (ENPs) 从自然环境转移到生物群中的关键作用。我们的结果强调了当存在金属污染物时 MPs 积累和运输 ENPs 的潜力增加，这增加了目前对 MPs 以及实际环境中各种水生污染物的环境归宿和不利影响的理解。随后释放的 MP 粘附的 CeNPs 和 HMs 在水介质和各种模拟消化液之间显着不同，验证了 MPs 通过摄入 MPs 和营养转移将工程纳米粒子 (ENPs) 从自然环境转移到生物群中的关键作用。我们的结果强调了当存在金属污染物时 MPs 积累和运输 ENPs 的潜力增加，这增加了目前对 MPs 以及实际环境中各种水生污染物的环境归宿和不利影响的理解。随后释放的 MP 粘附的 CeNPs 和 HMs 在水介质和各种模拟消化液之间显着不同，验证了 MPs 通过摄入 MPs 和营养转移将工程纳米粒子 (ENPs) 从自然环境转移到生物群中的关键作用。我们的结果强调了当存在金属污染物时 MPs 积累和运输 ENPs 的潜力增加，这增加了目前对 MPs 以及实际环境中各种水生污染物的环境归宿和不利影响的理解。