Institut des Sciences Exactes et Appliquées, Université de la Nouvelle-Calédonie BP R4, 98851, Nouméa Cedex, Nouvelle-Calédonie, France.
UMR 6298, ARTEHIS, Université de Bourgogne-Franche Comté-CNRS-Culture, 6 bd Gabriel, Bat. Gabriel, F-21000, Dijon, France.
Environ Monit Assess. 2018 Oct 18;190(11):638. doi: 10.1007/s10661-018-7029-0.
The aim of this study was to determine the mobilization capability of Ni, Co, and Mn contained in New Caledonian ultramafic soils. Two series of soils were sampled: bare-surface mining soils in a Ni-mining context (n = 10), and forest soils, either in the vicinity of mine-working areas (n = 3) or far away from any known mining activity (n = 2). We focused on the < 100 μm soil fraction, because of its sensitivity to wind erosion, and its possible dissemination toward urbanized areas. In order to assess maximum potential metal mobility, EDTA kinetic extractions were performed over 24 h. Extraction curves were modeled as the sum of two first-order reactions. The first EDTA extracted pool corresponds to "quickly" released metals, while the second pool corresponds to "slowly" released metals. The remaining fraction is the EDTA non-extractable pool. Extractable Ni, Co, and Mn were always low in relation to total concentrations (< 5% for Ni, and 5-35% for Co and Mn). The extraction rate of the less labile pool was significantly higher for forest soils than for mining soils, whatever the metal. Despite the greater extractability potential in forest surface soils, mining soils represent a bigger environmental risk, because of their high metal content and, above all, because of their predisposition to surface runoff and eolian deflation.
本研究旨在确定新喀里多尼亚超镁铁质土壤中所含镍、钴和锰的迁移能力。采集了两个系列的土壤样本：镍矿区的无植被表土（n=10），以及矿区附近的森林土壤（n=3）或远离任何已知采矿活动的森林土壤（n=2）。我们专注于<100μm的土壤部分，因为它对风蚀敏感，并且可能向城市化地区传播。为了评估最大的潜在金属迁移能力，进行了 24 小时的 EDTA 动力学提取。提取曲线被模拟为两个一级反应的总和。第一个 EDTA 提取的金属池对应于“快速”释放的金属，而第二个金属池对应于“缓慢”释放的金属。剩余的部分是 EDTA 不可提取的部分。可提取的镍、钴和锰的含量始终低于总浓度（镍<5%，钴和锰为 5-35%）。无论金属如何，森林土壤中较不稳定金属池的提取速率都明显高于采矿土壤。尽管森林表土的提取潜力更大，但采矿土壤的环境风险更大，因为它们的金属含量高，尤其是因为它们容易发生地表径流和风力侵蚀。
