Warnken Jan, Ohlsson Rohana, Welsh David T, Teasdale Peter R, Chelsky Ariella, Bennett William W
Australian Rivers Institute, Griffith School of Environment, Griffith University, Gold Coast Campus, QLD 4215, Australia.
Environmental Futures Research Institute, Griffith School of Environment, Griffith University, Gold Coast Campus, QLD 4215, Australia.
Chemosphere. 2017 Aug;180:388-395. doi: 10.1016/j.chemosphere.2017.03.142. Epub 2017 Apr 12.
Antimony is a priority environmental contaminant that is relatively poorly studied compared to other trace metal(loid)s. In particular, the behaviour of antimony in wetland sediments, where anaerobic conditions often dominate, has received considerably less attention compared to well-drained terrestrial soil environments. Here we report the results of a spatial assessment of antimony in the sediments and vegetation of a freshwater wetland exposed to stibnite tailings for the past forty years. The concentration of antimony in the sediment decreased rapidly with distance from the tailings deposit, from a maximum of ∼22,000 mg kg to ∼1000 mg kg at a distance of ∼150 m. In contrast, arsenic was distributed more evenly across the wetland, indicating that it was more mobile under the prevailing hypoxic/anoxic conditions. Less clear trends were observed in the tissues of wetland plants, with the concentrations of antimony in waterlilies (2.5-195 mg kg) showing no clear trends with distance from the tailings deposit, and no correlation with sediment concentrations. Sedges and Melaleuca sp. trees had lower antimony concentrations (<25 mg kg and 5 mg kg, respectively) compared to waterlilies, but showed a non-significant trend of higher concentrations closer to the tailings. For all vegetation types sampled, antimony concentrations were consistently lower than arsenic concentrations (Sb:As = 0.27-0.31), despite higher concentrations of antimony in the sediment. Overall, the results of this study highlight clear differences in the behaviour of antimony and arsenic in freshwater wetlands, which should be considered during the management and remediation of such sites.
锑是一种优先控制的环境污染物，与其他痕量金属（类金属）相比，对其研究相对较少。特别是，与排水良好的陆地土壤环境相比，在通常以厌氧条件为主的湿地沉积物中，锑的行为受到的关注要少得多。在此，我们报告了一个淡水湿地沉积物和植被中锑的空间评估结果，该湿地在过去四十年中一直受到辉锑矿尾矿的影响。沉积物中锑的浓度随着与尾矿堆距离的增加而迅速降低，从最大值约22,000毫克/千克降至距离约150米处的约1000毫克/千克。相比之下，砷在整个湿地的分布更为均匀，这表明在当前的缺氧/厌氧条件下，砷的流动性更强。在湿地植物组织中观察到的趋势不太明显，睡莲中锑的浓度（2.5 - 195毫克/千克）与距尾矿堆的距离没有明显趋势，且与沉积物浓度无关。莎草和白千层树的锑浓度（分别<25毫克/千克和5毫克/千克）低于睡莲，但在靠近尾矿处呈现出浓度较高的不显著趋势。对于所有采样的植被类型，尽管沉积物中锑的浓度较高，但锑的浓度始终低于砷的浓度（锑：砷 = 0.27 - 0.31）。总体而言，本研究结果突出了淡水湿地中锑和砷行为的明显差异，在对此类场地进行管理和修复时应予以考虑。
