Xinjiang Key Laboratory of Environmental Pollution and Bioremediation, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; University of Chinese Academy of Sciences, Beijing 100049, China; Geomicrobiology Group, School of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK.
Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China.
Chemosphere. 2019 Apr;221:486-492. doi: 10.1016/j.chemosphere.2019.01.073. Epub 2019 Jan 11.
Particulate organic matter (POM), composed of fine root fragments and other organic debris, is an important fraction of soil organic matter which can affect the fate of nanoparticles and influence their performance in nanoparticle-based remediation technologies due to aggregation. Effects of POM are not well studied compared with those of dissolved organic matter. In this research, POM was extracted from black soil by sieving, and heteroaggregation of selenium nanoparticles (SeNPs) with POM and consequences for elemental mercury (Hg) immobilization were investigated. It was found that low concentrations of more negatively charged POM (0-60 mg L) inhibited homoaggregation as well as heteroaggregation with SeNPs which had a lower negative charge through electrostatic repulsion. In the presence of high concentrations of POM (80-100 mg L), SeNPs were more likely to attach to POM with more Hg remaining in the POM since a larger concentration of nanoparticles would lead to more effective collisions. However, Hg immobilization efficiency using SeNPs was not significantly influenced by the addition of POM. This work is helpful to further understand the nanoparticle's behaviour in the environment and consequences for toxic metal remediation.
颗粒态有机物质（POM）由细根碎片和其他有机碎片组成，是土壤有机物质的一个重要组成部分，由于团聚作用，它会影响纳米颗粒的归宿，并影响基于纳米颗粒的修复技术中纳米颗粒的性能。与溶解态有机物质相比，POM 的作用尚未得到充分研究。在这项研究中，通过筛选从黑土中提取了 POM，并研究了 POM 与硒纳米颗粒（SeNPs）的异质聚集及其对元素汞（Hg）固定的影响。结果发现，低浓度带更多负电荷的 POM（0-60mg/L）通过静电排斥抑制了 SeNPs 的同质聚集和异质聚集，因为带更多负电荷的 SeNPs 之间更容易发生静电排斥。而在高浓度 POM（80-100mg/L）存在的情况下，由于更多的纳米颗粒会导致更有效的碰撞，因此 SeNPs 更有可能与 POM 结合，而更多的 Hg 则留在 POM 中。然而，添加 POM 对使用 SeNPs 固定 Hg 的效率没有显著影响。这项工作有助于进一步了解纳米颗粒在环境中的行为及其对有毒金属修复的影响。
