生物膜和土壤矿物对人工纳米颗粒在饱和多孔介质传输的影响

本文探究了人工纳米颗粒(NPs)在饱和多孔介质中的传输规律和影响机制，重点阐明生物膜和土壤矿物对纳米颗粒传输的影响及其机制。结果表明，在干净的石英砂介质中，不同种类和粒径NPs的传输效率具有明显差异，不同种类NPs传输效率表现为ZnO> CeO2>Fe2O3；对于报告粒径在20～100 nm之间的CeO2 NPs，粒径的增加有助于其在多孔介质的传输。溶液离子强度的增大会降低Zn O NPs的传输，而NPs浓度的增大不利于其在饱和多孔介质的传输，传统的DLVO理论能够很好地解释NPs在无涂层饱和多孔介质中的传输。生物膜和土壤矿物均能抑制纳米颗粒在饱和多孔介质的传输，其主要通过对纳米颗粒的吸附和异质聚集作用影响纳米颗粒的传输，非DLVO相互作用以及介质涂层的表面特性对增强纳米颗粒沉积有很大贡献。

Influence of Biofilms and Soil Minerals on Transport of Engineered Nanoparticles in Saturated Porous Media

The migration mechanism of engineered nanoparticles (NPs) in soils largely determine their environmental behavior and effects. There are a large number of components such as biofilms and soil minerals in the natural soil environment, and at present, it still needs further research on the transport laws and influencing mechanisms of NPs in real soil environments. In this study, we explored the transport laws and the influencing mechanisms of NPs in saturated porous medium by changing the environmental conditions of NPs and the coating of the medium in the packed column, focusing on elucidating the effects of biofilms and soil minerals on the transport of NPs and the underlying mechanisms. The results show that in the clean quartz sand medium, the transmission efficiencies of different types and sizes of NPs are significantly different. The transmission efficiency of different NPs is ZnO > CeO2 > Fe2O3, and the increase of particle size within a certain range contributes to the transmission of nanoparticles in porous media. The enhanced ionic strength of the solution would decrease the transport of ZnO NPs, while the increased concentration of NPs would not benefit their transport in the saturated porous medium, and the traditional DLVO theory can well explain the transport of NPs in the uncoated saturated porous medium. Both biofilms and soil minerals can inhibit the transport of nanoparticles in saturated porous medium, which mainly affects the transport of nanoparticles through adsorption and heteroaggregation effects on nanoparticles, and non-DLVO interactions as well as the surface characteristics of the coatings contribute greatly to enhance nanoparticle deposition. Therefore, the widespread presence of biofilm and soil minerals in soil may greatly inhibit the transport efficiency of nanoparticles, which is of great significance for further understanding the environmental behavior and ecological risk of NPs in soil.