Impact of arsenic releaching from excavated rock after once-arsenic leaching on potential arsenic leaching
Impact of arsenic releaching from excavated rock after once-arsenic leaching on potential arsenic leaching
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DOI：
10.1007/s10653-022-01418-2
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发表时间：
2022-10
影响因子：
4.2
通讯作者：
Shoji Suzuki;M. Katoh
中科院分区：
文献类型：
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作者：
Shoji Suzuki;M. Katoh
从城市和山区挖掘出大量天然含砷岩石用于建筑。对这些挖掘出的岩石进行化学固定等处理以供再利用。为了设计此类处理方法，必须确定挖掘出的岩石中潜在的可浸出砷含量。本研究旨在了解一次砷浸出后从挖掘岩石中释放的砷量是否应包含在潜在可浸出砷量中或使用顺序提取程序（SEP）进行估算。即使是砷浸出量低于 0.01 mg L−1 的挖掘岩石，砷的再浸出量也超过 0.01 mg L−1，这一量相当于砷未浸出岩石中砷浸出量的约 12%。无论砷是否被浸出，砷（再）浸出量相当于使用 SEP 易溶级分中砷的 84-116% (102±7%)。这些结果表明，从挖掘的岩石中（再）浸出的砷的来源是通过 SEP 作为易溶部分提取的砷，无论岩石是否经过砷浸出。这项研究的结果表明，从挖掘的岩石中释放的砷量应考虑在潜在的可浸出砷量中。此外，通过执行SEP可以相对容易地估计潜在的可浸出砷量。
Massive quantities of naturally arsenic-containing rocks are excavated from urbanized and mountainous areas for construction. Treatments such as chemical immobilization are applied to such excavated rocks for reuse. To design such treatments, determining the potentially leachable arsenic amounts in excavated rocks is imperative. This study aims to understand whether the arsenic releached amount from the excavated rock after once-arsenic leaching should be included in the potentially leachable arsenic amount or estimated using the sequential extraction procedure (SEP). Arsenic was releached at exceeding 0.01 mg L−1, even from the excavated rock that leached arsenic to less than 0.01 mg L−1, and this amount corresponded to approximately 12% of that of arsenic leached from the arsenic non-leached rock. The arsenic (re)leached amount corresponded to 84–116% (102 ± 7%) of that of arsenic in the readily soluble fraction using SEP, regardless of whether the arsenic was leached or not. These results indicate that the source of arsenic (re)leached from the excavated rock is arsenic extracted as the readily soluble fraction through SEP, regardless of whether the rock was arsenic-leached or not. This study’s findings suggest that the arsenic releached amount from the excavated rock should be considered in the potentially leachable arsenic amount. In addition, the potentially leachable arsenic amount can be relatively and readily estimated by performing SEP.