In this work, a novel pristine coordination polymer gel composed of zirconium and 2-amino-5-mercapto-1,3,4-thiadiazole is unveiled and explored to remove Cr(VI) from aqueous systems. A Box–Behnken design, coupled with a genetic algorithm and desirability function, was used for optimizing the controllable factors for maximum removal efficiency. Under optimized conditions (A = 50 mg L^–1, B = 40 mg, C = 90 min, and D = 4), 99% of Cr(VI) was removed, and the saturation adsorption capacity recorded was 132.37 mg g^–1. The adsorption data were investigated through statistical physics modeling. The most suited statistical physics model (monolayer with three energies; R² = 0.994–0.997, χ² = 0.008–0.024), combined with site energy distribution analysis, XPS, and FTIR, unraveled the uptake mechanism. At the first and third active sites, Cr(VI) uptake was multimolecular (n > 1), while at the second active site, it was a mixed multimolecular (298 K, n > 1) and multidocking (308 and 318 K, n < 1). The adsorption energy values indicated the involvement of coordination exchange (E₁ = 53.40–58.47 kJ mol^–1), electrostatic interaction (E₂ = 29.56–32.29 kJ mol^–1), and hydrogen bonding (E₃ = 24.68–28.35 kJ mol^–1) in Cr(VI) adsorption. The BSf(1.5, α) model fitted best (R² = 0.976–0.994, χ² = 0.023–0.377) to the kinetic data under all conditions. Common coexisting ions had no significant impact on removal efficiency (%R > 97% at 1:3), and the sorbent could be reutilized up to 5 uptake-elution cycles (>96% efficiency). The practical utility of ZrAMTD was investigated by remediating Cr(VI) contaminated real water samples (%R ≥ 92.91%).

中文翻译：

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Cr（VI） 吸附到配位聚合物凝胶上的位点能量分布与统计物理建模耦合


在这项工作中，揭示了一种由锆和 2-氨基-5-巯基-1,3,4-噻二唑组成的新型原始配位聚合物凝胶，并探索了从水性体系中去除 Cr（VI） 的方法。Box-Behnken 设计与遗传算法和意愿函数相结合，用于优化可控因素以实现最大去除效率。在优化条件下（A = 50 mg L^–1，B = 40 mg，C = 90 min，D = 4），去除了 99% 的 Cr（VI），记录的饱和吸附容量为 132.37 mg g^–1。通过统计物理建模研究吸附数据。最合适的统计物理模型（具有三种能量的单层;R² = 0.994–0.997，χ² = 0.008–0.024），结合位点能量分布分析、XPS 和 FTIR，揭示了摄取机制。在第一和第三个活性位点，Cr（VI） 摄取是多分子 （n > 1），而在第二个活性位点，它是混合多分子 （298 K， n > 1） 和多对接 （308 和 318 K， n < 1）。吸附能值表明 Cr（VI） 吸附涉及配位交换 （E₁ = 53.40–58.47 kJ mol^–1）、静电相互作用 （E₂ = 29.56–32.29 kJ mol^–1） 和氢键 （E₃ = 24.68–28.35 kJ mol^–1）。BSf（1.5， α） 模型在所有条件下对动力学数据的拟合最好 （R² = 0.976–0.994， χ² = 0.023–0.377）。共存的共同离子对去除效率没有显著影响（%R > 97%，1：3），吸附剂可以在多达5次吸收-洗脱循环中重复使用（>96%效率）。 通过修复受 Cr（VI） 污染的真实水样 （%R ≥ 92.91%） 来研究 ZrAMTD 的实际效用。