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.
Xinjiang Key Laboratory of Environmental Pollution and Bioremediation, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; College of Environment, Zhejiang University of Technology, Hangzhou 310014, China.
Sci Total Environ. 2019 Jun 10;668:303-309. doi: 10.1016/j.scitotenv.2019.02.457. Epub 2019 Mar 1.
Salinity can be a significant environmental stress which can govern the fate of nanoparticles in the environment as well as other factors such as pH, natural organic matter and minerals. In this research, the effects of salinity on the behavior of biogenic selenium nanoparticles (BioSeNPs) and consequences for elemental mercury (Hg) immobilization in soil and soil solutions were investigated. It was found that homoaggregation and sedimentation of BioSeNPs were enhanced significantly with increasing salinity. Compression of the electric double layers of BioSeNPs at high ionic strengths resulted in attractive van der Waals forces dominating and leading to enhanced aggregation. Moreover, neutralization of the surface negative charge of BioSeNPs by divalent cations and the bridging of BioSeNPs via calcium binding to surface functional groups were also associated with enhanced aggregation. Such enhanced aggregation exerted inhibition of Hg immobilization in soil solutions/soils of varying salinity. These results indicate that salinity is an important environmental factor governing aggregation of BioSeNPs and therefore influencing the efficiency of Hg immobilization, and possible remediation treatments, as a consequence.
盐度是一种重要的环境胁迫因素，它可以控制纳米颗粒在环境中的命运，以及其他因素，如 pH 值、天然有机物和矿物质。在这项研究中，研究了盐度对生物源硒纳米颗粒（BioSeNPs）行为的影响，以及对土壤和土壤溶液中元素汞（Hg）固定的后果。研究发现，随着盐度的增加，BioSeNPs 的同源聚集和沉淀显著增强。在高离子强度下，BioSeNPs 双电层的压缩导致吸引力的范德华力占主导地位，从而导致聚集增强。此外，二价阳离子中和 BioSeNPs 的表面负电荷以及通过钙与表面官能团结合桥联 BioSeNPs 也与聚集增强有关。这种增强的聚集作用抑制了不同盐度的土壤溶液/土壤中 Hg 的固定。这些结果表明，盐度是控制 BioSeNPs 聚集的一个重要环境因素，因此会影响 Hg 固定的效率，以及可能的修复处理效果。
