Chemical Engineering and Pharmaceutics School, Henan University of Science and Technology, Luoyang 471023, PR China; Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Sciences, Chinese Academy of Sciences, Nanjing 210008, PR China; Luoyang Key Laboratory of Soil Pollution Remediation Engineering, Henan University of Science and Technology, Luoyang 471023, PR China.
Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, PR China.
J Hazard Mater. 2022 Sep 15;438:129421. doi: 10.1016/j.jhazmat.2022.129421. Epub 2022 Jun 25.
Natural organic matter (NOM) and iron oxides have been proved to be crucial factors controlling the behaviors of nanoparticles in heterogenous environment. Here, we conducted experimental and modeling study on the transport of titanium dioxide nanoparticles (TiO NPs) in iron oxide-coated quartz in the presence of NOM under acidic conditions. Results showed the antagonistic effects of iron oxides and NOM on TiO NPs mobility. The inhibition of iron oxides coated on quartz was crystal form-dependent other than quantity-dependent. Amorphous ferric oxyhydroxide with higher specific surface area brought more positive charge and favorable deposition sites onto quartz, and induced more retention of nanoparticles than two crystalline iron oxides, goethite and hematite. Dissolved organic matter (DOM) facilitated TiO NPs transport in iron oxide-coated quartz. In comparation with the limited enhancing effects of DOM, the NOM coatings on media surface partially or largely offset the inhibition of goethite on nanoparticles mobility through direct occupation of attachment sites and sites screening due to the steric repulsion of the macromolecules. Owing to the higher steric hindrance, humic acid, both in dissolved and media surface-bound states, exerted stronger facilitating effects on TiO NPs mobility relative to fulvic acid.
天然有机物 (NOM) 和氧化铁已被证明是控制纳米颗粒在非均相环境中行为的关键因素。在这里，我们在酸性条件下，在存在 NOM 的情况下，进行了实验和模拟研究，以研究 TiO2 纳米颗粒 (TiO NPs) 在氧化铁涂覆的石英中的迁移。结果表明，氧化铁和 NOM 对 TiO NPs 迁移性具有拮抗作用。氧化铁对石英的抑制作用不是取决于数量，而是取决于晶体形态。具有更高比表面积的无定形铁氢氧化物带来更多正电荷和有利的沉积位置到石英上，并导致比两种结晶氧化铁（针铁矿和赤铁矿）更多的纳米颗粒保留。溶解有机物 (DOM) 促进了 TiO NPs 在氧化铁涂覆的石英中的迁移。与 DOM 的有限增强作用相比，由于大分子的空间排斥，NOM 涂层部分或大部分抵消了针铁矿对纳米颗粒迁移性的抑制作用，因为 NOM 涂层占据了附着位点和位点筛选。由于空间位阻较高，腐殖酸在溶解和介质表面结合态下都比富里酸对 TiO NPs 迁移性产生更强的促进作用。
