Adsorption of Chalcophile Metals onto Thiol-based Resins: Modeling Adsorption Capacity and Behavior using Surface Complexation Modeling
Adsorption of Chalcophile Metals onto Thiol-based Resins: Modeling Adsorption Capacity and Behavior using Surface Complexation Modeling
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DOI：
10.1016/j.colsurfa.2023.132329
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发表时间：
2023-08
期刊：
影响因子：
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通讯作者：
Qiang Yu;J. Fein
中科院分区：
文献类型：
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作者：
Qiang Yu;J. Fein
硫醇树脂从水溶液中吸附亲硫金属是一种有效的手段，重新利用这些金属和补救废物流，和预测建模方法是必要的，以设计和优化吸附应用。在这项研究中，电位滴定测量，金属吸附实验和表面络合建模（SCM）的方法被用来表征三个硫醇基树脂（BT40，SP 70和SP300），并模拟其质子，镉，锌，铅吸附容量和行为。我们发现，镉吸附到三种树脂上的程度强烈相关的质子活性巯基网站上的每一个树脂的测量浓度，和BT40树脂具有显着较高的浓度的质子活性巯基网站比其他两种树脂测试。使用BT40作为模型树脂，我们证明了在树脂上的Cd-硫醇表面络合物的测量的稳定常数（K）成功地解释了在宽范围的实验条件下金属：树脂比率和pH的影响。在BT 40树脂上金属-硫醇表面络合物的K值与Cd、Zn和Pb的金属-硫醇水溶液络合物的K值之间存在线性自由能关系（LFER）。该LFER可用于估算其他金属-硫醇树脂表面络合物的K值，这些金属-硫醇树脂表面络合物尚未通过实验测量，因此能够预测各种金属在各种系统条件下在硫醇基树脂上的吸附行为。这项研究表明，SCM的方法，加上电位滴定测量和金属吸附实验，代表了一个强大的工具，用于设计和优化的策略，从水介质中分离和回收亲铜金属。
Adsorption of chalcophile metals from aqueous solution by thiol resins represents an efficient means of reusing these metals and remediating waste streams, and a predictive modeling approach is needed in order to design and optimize adsorption applications. In this study, potentiometric titration measurements, metal adsorption experiments and surface complexation modeling (SCM) approaches were used to characterize three thiol-based resins (BT40, SP70, and SP300), and to model their proton, Cd, Zn, and Pb adsorption capacities and behaviors. We find that the extent of Cd adsorption onto the three resins correlates strongly to the measured concentration of proton-active thiol sites on each resin, and that the BT40 resin has a significantly higher concentration of proton-active thiol sites than the other two resins tested. Using the BT40 as a model resin, we demonstrate that the measured stability constant (K) of the Cd-thiol surface complex on the resin successfully accounts for the effects of both the metal:resin ratio and pH over a wide range of experimental conditions. We also find that a linear free-energy relationship (LFER) exists between theKvalues of metal-thiol surface complexes on the BT40 resin and theKvalues of metal-thiol aqueous complexes for Cd, Zn and Pb. This LFER can be used to estimate theKvalues of other metal-thiol resin surface complexes that have not been measured experimentally, therefore enabling prediction of the adsorption behavior of a wide range of metals onto thiol-based resins under a wide range of system conditions. This study demonstrates that a SCM approach, coupled with potentiometric titration measurements and metal adsorption experiments, represents a powerful tool for the design and optimization of strategies for separating and recovering chalcophile metals from aqueous media.