Co-adsorption of phosphate and zinc(II) on the surface of ferrihydrite
Co-adsorption of phosphate and zinc(II) on the surface of ferrihydrite
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DOI：
10.1016/j.chemosphere.2015.09.083
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发表时间：
2016-02-01
期刊：
影响因子：
8.8
通讯作者：
He, Hongping
中科院分区：
文献类型：
--
作者：
Liu, Jing;Zhu, Runliang;He, Hongping
水铁矿（Fh）对于影响重金属阳离子和氧阴离子的迁移和转化具有重要意义。为了加深对 Fh 表面共吸附反应的理解，测定了磷酸盐和 Zn(II) 从水溶液到合成 Fh 的共吸附。批量实验证明了 Fh 上磷酸盐和 Zn(II) 的协同吸附。在pH 3.5-6范围内，两种污染物的吸附在单一溶质吸附系统中表现出较强的pH依赖性，但在同时吸附系统中这种依赖性减轻。 X射线光电子能谱(XPS)显示，在单一和同时吸附体系中，Zn 2p(1/2)和Zn 2p(3/2)结合能的化学位移比P 2p更显着。另一方面，原位衰减全反射傅立叶变换红外 (ATR-FTIR) 观察到同步系统中磷酸盐外层和内层复合物的形成增加。因此，两种污染物的协同吸附可能归因于三元复合物的形成以及静电相互作用，而不能完全排除表面沉淀。根据批量吸附实验和结构表征的结果，这两种污染物很可能在同时吸附系统中形成磷酸盐桥联三元络合物（Fe-P-Zn）。 (C) 2015 Elsevier Ltd. 保留所有权利。
Ferrihydrite (Fh) is of great importance in affecting the migration and transformation of heavy-metal cations and oxyanions. To advance the understanding of co-adsorption reactions on Fh surface, the co-adsorption of phosphate and Zn(II) from aqueous solution to a synthesized Fh was determined. The batch experiments demonstrated a synergistic adsorption of phosphate and Zn(II) on Fh. In the pH range of 3.5-6, the adsorption of the two contaminants showed strong pH dependence in the single solute adsorption systems, but the dependence alleviated in the simultaneous adsorption system. X-ray photoelectron spectroscopy (XPS) revealed that the chemical shifts of Zn 2p(1/2) and Zn 2p(3/2) binding energies were more significant than that of P 2p in the single and simultaneous adsorption systems. On the other side, in situ attenuated total reflectance Fourier transform infrared (ATR-FTIR) observed increased formation of outer- and inner-sphere complexes of phosphate in the simultaneous system. Thus, the synergistic adsorption of the two contaminants could be attributed to the formation of ternary complexes as well as electrostatic interactions, while surface precipitation could not be completely ruled out. On the basis of the results from both the batch adsorption experiments and structural characterization, these two contaminants were likely to form phosphate-bridged ternary complexes ( Fe-P-Zn) in the simultaneous adsorption system. (C) 2015 Elsevier Ltd. All rights reserved.