Competitive sorption of Ni and Zn at the aluminum oxide/water interface: an XAFS study.
Competitive sorption of Ni and Zn at the aluminum oxide/water interface: an XAFS study.
复制标题
Ni 和 Zn 在氧化铝/水界面的竞争吸附：XAFS 研究。
DOI：
10.1186/s12932-018-0054-7
复制
发表时间：
2018-03-27
影响因子：
2.3
通讯作者：
Li W
中科院分区：
文献类型：
--
作者：
Gou W;Siebecker MG;Wang Z;Li W
从工业和农业过程中浸出的痕量金属（如镍，锌）往往同时存在于污染的土壤和沉积物中。它们的流动性，生物利用度和生态毒性受到矿物/溶液界面吸附和共吸附的影响。痕量金属的共吸附已经在宏观水平上进行了研究，但由于缺乏光谱信息，对分子尺度的共吸附过程没有清楚的了解。在这项研究中，镍和锌的吸附铝氧化物（γ-Al 2 O3）在二元山梨酸盐体系进行了比较，他们在单一山梨酸盐体系中的吸附作为pH值的函数，使用宏观批次实验和同步加速器为基础的X射线吸收精细结构光谱。在pH 6.0时，Ni和Zn以内球表面络合物的形式吸附在γ-Al 2 O3上，并竞争有限的活性位。在二元山梨酸盐体系中，由于Ni对金属氧化物表面的亲和力较低，Ni对Zn的吸附没有影响。相反，Zn对金属氧化物表面具有更高的亲和力，并降低了Ni吸附。在pH 7.5时，Ni和Zn作为混合金属表面沉淀物被吸附，包括Ni-Al层状双氢氧化物（LDHs）、Zn-Al LDHs和可能的Ni-Zn-Al层状三元/三元氢氧化物。此外，在pH 7.5，镍和锌不表现出竞争吸附的二元系统中的效果。综上所述，这些结果表明，pH严重影响反应产物，并提供了一个重要的科学依据，以了解潜在的移动性，生物利用度和生态毒性的镍和锌在自然和污染的地球化学环境。
Trace metals (e.g. Ni, Zn) leached from industrial and agricultural processes are often simultaneously present in contaminated soils and sediments. Their mobility, bioavailability, and ecotoxicity are affected by sorption and cosorption at mineral/solution interfaces. Cosorption of trace metals has been investigated at the macroscopic level, but there is not a clear understanding of the molecular-scale cosorption processes due to lack of spectroscopic information. In this study, Ni and Zn cosorption to aluminum oxides (γ-Al2O3) in binary-sorbate systems were compared to their sorption in single-sorbate systems as a function of pH using both macroscopic batch experiments and synchrotron-based X-ray absorption fine structure spectroscopy. At pH 6.0, Ni and Zn were sorbed as inner-sphere surface complexes and competed for the limited number of reactive sites on γ-Al2O3. In binary-sorbate systems, Ni had no effect on Zn sorption, owning to its lower affinity for the metal oxide surface. In contrast, Zn had a higher affinity for the metal oxide surface and reduced Ni sorption. At pH 7.5, Ni and Zn were sorbed as mixed-metal surface precipitates, including Ni–Al layered double hydroxides (LDHs), Zn–Al LDHs, and likely Ni–Zn–Al layered triple/ternary hydroxides. Additionally, at pH 7.5, Ni and Zn do not exhibit competitive sorption effects in the binary system. Taken together, these results indicated that pH critically influenced the reaction products, and provides a crucial scientific basis to understand the potential mobility, bioavailability, and ecotoxicity of Ni and Zn in natural and contaminated geochemical environments.
登录
查看更多内容
影响因子：
4.3
作者：
Aschner, M
通讯作者：
Aschner, M
DOI：
10.1080/00103629709369843
发表时间：
1997-01-01
影响因子：
1.8
作者：
Bibak, A
通讯作者：
Bibak, A
影响因子：
5.4
作者：
DEROY, A;BESSE, JP;BONDOT, P
通讯作者：
BONDOT, P
影响因子：
11.4
作者：
Ford, RG;Sparks, DL
通讯作者：
Sparks, DL
影响因子：
11.4
作者：
Li, Wei;Livi, Kenneth J. T.;Sparks, Donald L.
通讯作者：
Sparks, Donald L.