Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Permoserstr. 15, 04318 Leipzig, Germany.
Chemosphere. 2017 Jul;178:277-281. doi: 10.1016/j.chemosphere.2017.03.073. Epub 2017 Mar 21.
High carbonate content of the European Kupferschiefer ore deposits is a challenge for acid copper leaching (pH ≤ 2). Therefore investigating the mobility behavior of Cu(II) under conditions related to an alternative, neutrophil biohydrometallurgical Cu(II) leaching approach is of interest. As glutamic acid (Glu) might be present as a component in the growth media, we studied its effects on the adsorption of Cu(II) onto kaolinite. The binary and ternary batch sorption measurements of Cu(II) and Glu onto kaolinite were performed in the presence of 10 mM NaClO as background electrolyte and at a pH range from 4 to 9. Sorption experiments were modeled by the charge-distribution multi-site ion complexation (CD-MUSIC) model by using single sorption site (≡SOH) and monodentate surface complexation reactions. Glu sorption on kaolinite is weak (<10%) and independent of pH. Furthermore, Glu slightly enhances the Cu(II) sorption at low pH but strongly hinders (up to 50%) the sorption at higher pH and therewith enhances copper mobility. The results of isotherms show that Cu(II)-Glu sorption onto kaolinite mimics the Freundlich model. The proposed CD-MUSIC model provides a close fit to the experimental data and predicts the sorption of Cu(II), Cu(II)-Glu and Glu onto kaolinite as well as the effect of Glu on Cu(II) mobility.
高碳酸盐含量的欧洲斑脱岩矿床是酸性铜浸出（pH≤2）的一个挑战。因此，研究铜（II）在与替代的、中性生物冶金铜（II）浸出方法相关的条件下的迁移行为是很有意义的。由于谷氨酸（Glu）可能作为生长介质的一个组成部分存在，我们研究了它对铜（II）在高岭石上吸附的影响。在 10 mM NaClO 作为背景电解质和 pH 值范围从 4 到 9 的条件下，进行了铜（II）和 Glu 在高岭石上的二元和三元分批吸附测量。使用单吸附位（≡SOH）和单齿表面络合反应，通过电荷分布多位点离子络合（CD-MUSIC）模型对吸附实验进行了建模。Glu 在高岭石上的吸附较弱（<10%）且与 pH 值无关。此外，Glu 在低 pH 值下略微增强了铜（II）的吸附，但在较高 pH 值下强烈阻碍（高达 50%）了吸附，从而提高了铜的迁移性。等温线的结果表明，Cu（II）-Glu 在高岭石上的吸附模拟了 Freundlich 模型。所提出的 CD-MUSIC 模型对实验数据有很好的拟合，并预测了 Cu（II）、Cu（II）-Glu 和 Glu 在高岭石上的吸附以及 Glu 对 Cu（II）迁移性的影响。
