Insight into the effect of SO42− on the precipitation and solubility of ferric arsenate in acidic solutions: Implication for arsenic mobility and fate
Insight into the effect of SO42− on the precipitation and solubility of ferric arsenate in acidic solutions: Implication for arsenic mobility and fate
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深入了解 SO42™ 对酸性溶液中砷酸铁的沉淀和溶解度的影响：对砷迁移率和归宿的影响
DOI：
10.1016/j.chemgeo.2022.120900
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发表时间：
2022-07
期刊：
影响因子：
3.9
通讯作者：
Yongfeng Jia
中科院分区：
文献类型：
--
作者：
Xu Ma;Shaofeng Wang;Mario A. Gomez;Zidan Yuan;Xing Wu;Shuhua Yao;Yongfeng Jia
硫酸根（SO₄²⁻）对砷（V）和铁（III）的沉淀、所生成固相的稳定性及其潜在机制的影响，在酸性水体（如酸性矿山排水）中强烈影响着砷的迁移和归宿，但目前仍不清楚。本工作系统地研究了在pH为1.2和1.8时，不同量的硫酸根存在下砷酸铁相的沉淀、分解和沉降特性。结果表明，一方面，硫酸根的存在延迟了水相中砷和铁的去除，并提高了固体砷酸铁的溶解度。地球化学模拟结果表明，共存的硫酸根诱导了水溶液中硫酸根 - 铁（III）络合物的形成，导致生成的砷酸铁固相分解。另一方面，硫酸根的添加提高了生成的砷酸铁的生长速率并加速了固体的沉降。粒度分布和透射电子显微镜分析表明，硫酸根的存在显著增大了砷酸铁聚集体的尺寸。红外光谱和S K - 边X射线吸收近边结构结果证明，硫酸根通过形成砷酸铁 - 硫酸固溶体而结合到砷酸铁的结构中，每个硫酸根四面体大约与两个FeO₆八面体配位。S K - 边扩展X射线吸收精细结构结果给出的平均S - Fe原子间距为3.21 Å。这些结果表明，硫酸根的存在主要通过S - O - Fe桥键增大了砷酸铁的聚集体尺寸，进而加速了硫酸根 - 砷酸铁的沉降。本研究中硫酸根在影响砷方面的这种矛盾作用对于理解酸性体系中砷的迁移和归宿以及砷酸铁矿物的形成机制具有重要意义。
The effect of sulfate (SO 4 2− ) on the precipitation of As(V) and Fe(III) and the stability of the generated solid phase as well as its underlying mechanisms, which strongly influences the transportation and fate of As in acidic waters (such as acid mine drainage), is still not well known. This work systematically investigated the precipitation, decomposition, and settling properties of the ferric arsenate phase in the presence of different amount of SO 4 2− at pH 1.2 and 1.8. The results showed that on the one side, the presence of SO 4 2− delayed the removal of As and Fe from the aqueous phase and enhanced the solubility of solid ferric arsenate. The geochemical modelling results showed that the coexisting SO 4 2− induced the formation of aqueous SO 4 2− -Fe(III) complexes, inducing the decomposition of produced ferric arsenate solid phase. On the other side, the addition of SO 4 2− promoted the growth rate of generated ferric arsenate and accelerated the settling of solids. The particle size distribution and transmission electron micorscopy analyses elucidated that the presence of SO 4 2− significantly enlarged the ferric arsenate aggregate size. The infrared spectroscopy and S K -edge X-ray absorption near edge structure results proved that SO 4 2− is incorporated into the structure of ferric arsenate by forming ferric arsenate sulfate solid solution, with each SO 4 2− tetrahedron coordinating with approximately two FeO 6 octahedra. The S K -edge extended X-ray absorption fine structrure result gave an averaged S-Fe interatomic distance of 3.21 Å. These results demonstrated that the presence of SO 4 2− enlarged the aggregate size of ferric arsenate dominantly via the S-O-Fe bridging, and then accelerated the settling of SO 4 -ferric arsenate. The contrasting role of SO 4 2− in influencing As obtained in this study is significant for understanding the mobilization and fate of As and the formation mechanisms of ferric arsenate minerals in acidic systems.
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影响因子：
9.9
作者：
M. Gómez;L. Becze;M. Celikin;G. Demopoulos
通讯作者：
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影响因子：
8.8
作者：
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通讯作者：
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影响因子：
5
作者：
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J. Majzlan;Bronislava Lalinská;M. Chovan;Ľubomír Jurkovič;S. Milovská;J. Göttlicher
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影响因子：
5
作者：
Jia, Yongfeng;Xu, Liying;Demopoulos, George P.
通讯作者：
Demopoulos, George P.
影响因子：
5
作者：
D. Paktunc;A. Foster;S. Heald;Gilles Laflamme
通讯作者：
D. Paktunc;A. Foster;S. Heald;Gilles Laflamme