Arsenic speciation in the dispersible colloidal fraction of soils from a mine-impacted creek.
Arsenic speciation in the dispersible colloidal fraction of soils from a mine-impacted creek.
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DOI：
10.1016/j.jhazmat.2014.12.025
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发表时间：
2015-04
影响因子：
13.6
通讯作者：
S. Serrano;M. Gomez‐Gonzalez;Peggy A. O'Day;F. Laborda;E. Bolea;F. Garrido
中科院分区：
文献类型：
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作者：
S. Serrano;M. Gomez‐Gonzalez;Peggy A. O'Day;F. Laborda;E. Bolea;F. Garrido
可分散胶体组分中砷和铁的形态（DCF;采用非对称流场流分离（AsFlFFF）/电感耦合等离子体质谱（ICP-MS）联用技术，研究了富砷矿山废石堆中砷（As）、废石堆径流收集河床沉积物、河床底土和下游池塘沉积物中砷（As）的含量，透射电子显微镜（TEM）和X射线吸收（XAS）光谱。钙、铁和砷（Fe/As摩尔比为1.5）是垃圾堆DCF的主要成分。TEM/EDS和As和Fe XAS分析揭示了在该相同DCF中存在纳米颗粒臭葱石，以及在废物堆下游的所有样品中存在Fe纳米颗粒。砷和铁XAS显示As（V）吸附到下游样品的DCF中的纳米颗粒水铁矿上。显微X射线荧光分析表明，铁和砷在层状硅酸盐/铁3+（氧）氢氧化物聚集体从沉积池之间有很强的相关性。分馏分析表明，从河床样品的DCF的平均粒径小于河床底土和沉积物池塘样品。这些结果表明，一个重要的和可变的分数作为可能会绑定到可分散的胶体，可以从污染的土壤中释放，并在自然系统中向下游输送。
Arsenic and iron speciation in the dispersible colloid fraction (DCF; 10–1000 nm) from an As-rich mine waste pile, sediments of a streambed that collects runoff from waste pile, the streambed subsoil, and the sediments of a downstream pond were investigated by combining asymmetrical-flow field-flow fractionation (AsFlFFF)/inductively-coupled plasma–mass spectrometry (ICP–MS), transmission electron microscopy (TEM) and X-ray absorption (XAS) spectroscopy. Calcium, Fe and As (Fe/As molar ratio ∼ 1) were the main components of the DCF from waste pile. TEM/EDS and As and Fe XAS analysis revealed the presence of nanoparticle scorodite in this same DCF, as well as Fe nanoparticles in all samples downstream of the waste pile. Arsenic and Fe XAS showed As(V) adsorbed onto nanoparticulate ferrihydrite in the DCF of downstream samples. Micro-X-ray fluorescence indicated a strong correlation between Fe and As in phyllosilicate/Fe3+(oxi) hydroxide aggregates from the sediment pond. Fractionation analysis showed the mean particle size of the DCF from the streambed sample to be smaller than that of the streambed subsoil and sediment ponds samples. These results show that an important and variable fraction of As may be bound to dispersible colloids that can be released from contaminated soils and transported downstream in natural systems.