Key Laboratory for Environmental Factors Control of Agro-Product Quality Safety, Ministry of Agriculture and Rural Affairs, Tianjin, 300191, China.
Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China.
Environ Sci Technol. 2022 Mar 15;56(6):3524-3534. doi: 10.1021/acs.est.1c07574. Epub 2022 Feb 28.
The transport of nanoplastics (NPs) through porous media is influenced by dissolved organic matter (DOM) released from agricultural organic inputs. Here, cotransport of NPs with three types of DOM (biochar (BC), wheat straw (WS), and swine manure (SM)) was investigated in saturated goethite (GT)-coated sand columns. The results showed that codeposition of 50 nm NPs (50NPs) with DOM occurred due to the formation of a GT-DOM-50NPs complex, while DOM loaded on GT-coated sand and 400 nm NPs (400NPs) aided 400NPs transport due to electrostatic repulsion. According to the quantum chemical calculation, humic acid and cellulose played a significant role in 50NPs retardation. Owing to its high concentration, moderate humification index (HIX), and cellulose content, SM exhibited the highest retardation of 50NPs transport and promoting effect on 400NPs transport. Owing to a high HIX, the effect of BC on the mobility of 400NPs was higher than that of WS. However, high cellulose content in WS caused it to exhibit a 50NPs retardation ability that was similar to that of BC. Our results highlight the particle size selectivity and significant influence of DOM type on the transport of NPs and elucidate their quantum and colloidal chemical-interface mechanisms in a typical agricultural environment.
纳米塑料（NPs）通过多孔介质的迁移受到农业有机输入物释放的溶解有机物（DOM）的影响。在这里，研究了 NPs 与三种 DOM（生物炭（BC）、小麦秸秆（WS）和猪粪（SM））共运移在饱和针铁矿（GT）涂覆砂柱中的情况。结果表明，由于 GT-DOM-50NPs 复合物的形成，50nm NPs（50NPs）与 DOM 共沉淀，而 DOM 负载在 GT 涂覆砂和 400nm NPs（400NPs）上，由于静电排斥，有助于 400NPs 的迁移。根据量子化学计算，腐殖酸和纤维素对 50NPs 的阻滞作用显著。由于 SM 浓度高、腐殖化指数（HIX）适中、纤维素含量高，对 50NPs 迁移的阻滞作用最强，对 400NPs 迁移的促进作用最大。由于 HIX 较高，BC 对 400NPs 迁移的影响高于 WS。然而，WS 中高纤维素含量使其表现出与 BC 相似的 50NPs 阻滞能力。我们的结果突出了 DOM 类型对 NPs 迁移的粒径选择性和显著影响，并阐明了它们在典型农业环境中的量子和胶体化学界面机制。
