Enrichment of trace elements in ferromanganese concretions from terra rossa and their potential desorption
Enrichment of trace elements in ferromanganese concretions from terra rossa and their potential desorption
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红土铁锰结核中微量元素的富集及其潜在的解吸
DOI：
10.2343/geochemj.1.0156
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发表时间：
2012-04
影响因子：
0.8
通讯作者：
Ji-Feng Zhang
中科院分区：
文献类型：
--
作者：
Jin-Liang Feng;Yong-Chong Lin;Shao-Peng Gao;Ji-Feng Zhang
本文研究了铁锰结核（FMCs）及其周围的红色土（TR）基质中微量元素在白云岩上的分布，以加深我们对它们在岩溶风化成土过程中的活化、再分配和分馏的认识。这项研究表明，在TR的微量元素的特征已严重叠加风化和成壤过程。TR土壤剖面中FMCs的微量元素组成随深度变化很大。Be、Ni、Cu、Zn、As和Bi在FMCs中的浓度随深度的增加而波动，其它微量元素在剖面中的浓度随深度的增加而波动，但没有明显的变化趋势。有毒元素铬，砷，镉，铊和铅，以及钴，是显着富集在FMCs相对于周围TR矩阵：砷表现出很强的亲和力与铁，但铬和镉的含量并不显着相关的Mn或Fe。相应地，Co、Tl和Pb与FMCs中的Mn有关，而与Fe无关。在FMCs中，微量元素在Mn-Fe相中的分布和分配受特定位置的地层土壤环境控制，风化锋向下侵蚀。模拟酸雨的实验表明，无论释放量和解吸能力如何变化，FMCs的元素解吸通常都是pH依赖性的。此外，与锰相结合的有毒元素似乎很容易从FMCs中脱附。因此，在遭受严重土壤侵蚀和酸雨的农田地区，FMCs和TR中某些有毒元素的生物利用度、流动性和活性可能会增加。
The distributions of trace elements in ferromanganese concretions (FMCs) and the surrounding terra rossa (TR) matrix overlying dolomite have been examined to extend our understanding of their mobilization, redistribution and fractionation during karst weathering and pedogenesis. This study demonstrates that the characteristics of trace elements in TR have been severely overprinted by weathering and pedogenetic processes. The composition of trace elements in FMCs within TR soil profiles varies greatly with depth. The concentrations of Be, Ni, Cu, Zn, As and Bi in FMCs fluctuate and tend to increase with depth; other trace element concentrations fluctuate in the profile but show no clear trend. The toxic elements Cr, As, Cd, Tl and Pb, as well as Co, are significantly enriched in FMCs relative to the surrounding TR matrix: arsenic exhibits strong affinity with Fe, but Cr and Cd contents are not significantly correlated with either Mn or Fe. Correspondingly, Co, Tl and Pb are related to the Mn in FMCs rather than the Fe. In FMCs, trace element distribution and partitioning in the Mn‐Fe phases are governed by the location-specific formational pedoenvironment, with the weathering front etching downwards. Experiments with simulated acid rain indicate that desorption of elements from FMCs is generally pH-dependent regardless of the variation of the released amounts and their desorbability. Moreover, it seems that toxic elements bonded to Mn-phase were easily desorbed from FMCs. As a result, the bioavailability, mobility and activity of some toxic elements in FMCs and TR are potentially increased in field areas experiencing severe soil erosion and acid rain.
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影响因子：
3.9
作者：
A. Mee;E. Bestland;Nigel A. Spooner
通讯作者：
A. Mee;E. Bestland;Nigel A. Spooner
影响因子：
2.2
作者：
N. Whitehead;J. Hunt;D. Leslie;P. Rankin
通讯作者：
N. Whitehead;J. Hunt;D. Leslie;P. Rankin
影响因子：
6.1
作者：
J. Marques;Darrell G Schulze;Nilton Curi;S. Mertzman
通讯作者：
J. Marques;Darrell G Schulze;Nilton Curi;S. Mertzman
影响因子：
2.2
作者：
P. Rankin;C. W. Childs
通讯作者：
P. Rankin;C. W. Childs
影响因子：
6.1
作者：
B. Dawson;J. Fergusson;A. Campbell;E. Cutler
通讯作者：
B. Dawson;J. Fergusson;A. Campbell;E. Cutler