Jia Xiaocen, Majzlan Juraj, Ma Liyuan, Liu Peng, Fan Peikuan, Li Wanyu, Zhou Jianwei, Wen Bing
School of Environmental Studies, China University of Geosciences, 430078 Wuhan, PR China.
Institute of Geosciences, Friedrich Schiller University Jena, 07749 Jena, Germany.
J Hazard Mater. 2023 Oct 5;459:132212. doi: 10.1016/j.jhazmat.2023.132212. Epub 2023 Aug 2.
Colloids may play an important role in the geochemical cycle of antimony (Sb). However, the controlling behaviors of colloids on Sb fate in contaminated groundwater are not available. To investigate the effects of colloids on Sb mobility, groundwater samples from Xikuangshan Sb Mine's two main aquifers (the Ds aquifer and the Dx aquifer) were successively (ultra)filtered through progressively decreasing pore sizes (0.45 µm, 100 kDa, 50 kDa and 5 kDa). The results showed that 0.1-84.1% of Sb was adsorbed or carried by colloids, which corresponded to Sb concentration ranging between 0 and 2973 μg/L in the colloids (0.45 µm - 5 kDa). In both aquifers, Sb was closely associated with organic colloids (r = 0.72 p < 0.05 for the Dx aquifer, r = 0.94 p < 0.01 for the Ds aquifer). Parallel factor analysis of the three-dimensional fluorescence spectra determined that the protein-like substances in the Dx aquifer and the humus-like substances in the Ds aquifer controlled Sb behavior. X-ray absorption spectroscopy confirmed Sb complexing with organic substances. Competitive adsorption of As and Sb suppressed the complexation of colloids with Sb, particularly in the Dx aquifer (r = -0.71, p < 0.05). Sb mobility was also influenced by the redox of the groundwater system. As the oxidation-reduction potential and dissolved oxygen increased, Sb in the colloidal fractions decreased. These findings provide new insights into the mechanisms involved in Sb fate affected by colloids, establishing the theoretical basis for developing effective Sb and even metalloid pollution remediation strategies.
胶体可能在锑（Sb）的地球化学循环中发挥重要作用。然而，关于胶体对受污染地下水中锑归宿的控制行为尚不清楚。为了研究胶体对锑迁移率的影响，对锡矿山锑矿两个主要含水层（Ds含水层和Dx含水层）的地下水样本依次通过孔径逐渐减小的（超滤）过滤器（0.45 µm、100 kDa、50 kDa和5 kDa）进行过滤。结果表明，0.1%至84.1%的锑被胶体吸附或携带，这对应于胶体（0.45 µm - 5 kDa）中锑浓度在0至2973 μg/L之间。在两个含水层中，锑都与有机胶体密切相关（Dx含水层中r = 0.72，p < 0.05；Ds含水层中r = 0.94，p < 0.01）。三维荧光光谱的平行因子分析确定，Dx含水层中的类蛋白质物质和Ds含水层中的类腐殖质物质控制着锑的行为。X射线吸收光谱证实了锑与有机物质的络合。砷和锑的竞争吸附抑制了胶体与锑的络合，特别是在Dx含水层中（r = -0.71，p < 0.05）。锑的迁移率还受到地下水系统氧化还原的影响。随着氧化还原电位和溶解氧的增加，胶体部分中的锑减少。这些发现为胶体影响锑归宿的机制提供了新的见解，为制定有效的锑乃至类金属污染修复策略奠定了理论基础。
