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.
Key Laboratory of Soil Contamination Bioremediation of Zhejiang Province, Zhejiang A&F University, Hangzhou, 311300, PR China.
Chemosphere. 2019 Dec;237:124529. doi: 10.1016/j.chemosphere.2019.124529. Epub 2019 Aug 6.
The complexity of natural dissolved organic matter (DOM) motivates the determination of how DOM from diverse sources affects the environmental behaviors of engineered nanoparticles. Here, three types of DOM, DOM extracted from swine manure (SWDOM), sludge (SLDOM) and sediment (SEDOM), were characterized, and their effects on the transport of titanium dioxide nanoparticles (TiO NPs, 30 nm in diameter) were evaluated and compared with those of humic acid (HA). Characterization tests showed differences in the aromaticity and weight-average molecular weight (M) properties among the three extracted DOM solutions, and greater distinctions were found between the extracted DOM and HA. All the extracted DOM facilitated TiO NPs transport in acidic porous media. Nevertheless, the enhancing effects varied among the different extracted DOM types. SWDOM had a promoting effect on TiO NPs mobility that was equivalent to that of SEDOM and much higher than that of SLDOM. However, the facilitating effects of all three extracted DOM types were limited compared to that of HA. Based on the combined analysis of DOM properties and TiO NPs transport behaviors, it could be concluded that aromaticity and M were the key properties determining the limited promoting effects of DOM on TiO NPs mobility, and the specific UV absorbance at 280 nm (normalized by concentration, SUVA) was a facile and useful indicator of the DOM-promoted transport of TiO NPs. These findings revealed that transport potential in the presence of DOM would be overestimated if either HA or fulvic acid were chosen as the DOM model in studies.
天然溶解性有机质（DOM）的复杂性促使人们确定来自不同来源的 DOM 如何影响工程纳米粒子的环境行为。在这里，我们对三种 DOM 进行了特征描述，即从猪粪（SWDOM）、污泥（SLDOM）和沉积物（SEDOM）中提取的 DOM，评估了它们对二氧化钛纳米粒子（TiO NPs，直径 30nm）传输的影响，并与腐殖酸（HA）的影响进行了比较。特征测试表明，三种提取的 DOM 溶液在芳香度和重均分子量（M）性质上存在差异，并且提取的 DOM 与 HA 之间的差异更大。所有提取的 DOM 都促进了 TiO NPs 在酸性多孔介质中的传输。然而，不同提取的 DOM 类型之间的增强效果存在差异。SWDOM 对 TiO NPs 迁移的促进作用与 SEDOM 相当，比 SLDOM 高得多。然而，与 HA 相比，所有三种提取的 DOM 类型的促进作用都有限。根据 DOM 特性和 TiO NPs 传输行为的综合分析，可以得出结论，芳香度和 M 是决定 DOM 对 TiO NPs 迁移的有限促进作用的关键性质，并且 280nm 处的特定紫外吸光度（归一化为浓度，SUVA）是 DOM 促进 TiO NPs 传输的一种简便而有用的指标。这些发现表明，如果在研究中选择 HA 或富里酸作为 DOM 模型，那么在 DOM 存在的情况下，传输潜力可能会被高估。
