While technological advancements in treating electroplating wastewater continue, removing high concentrations of Ni²⁺ and Co²⁺ remains a challenge. Surface functionalization of clay has emerged as a pivotal approach for effectively removing heavy metals, rivaling intercalation modification in its effectiveness. This study investigated the adsorption performance and mechanisms of a phosphonate-modified layered double hydroxide material, employing batch experiments and simulation calculations to elucidate the impact of surface modification on adsorption behavior. Briefly, various characterization techniques confirmed that the layered double hydroxide synthesized through co-precipitation exhibited a sheet-like morphology, with phosphonate groups anchoring onto the clay surface following functionalization. Under optimal conditions (pH=6.0, t=60 min, and C₀=300 mg/L), the material demonstrated high uptake capacities for Ni²⁺ (198.01 mg/g) and Co²⁺ (180.18 mg/g), surpassing most previously reported adsorbents. The adsorption kinetics for Ni²⁺ and Co²⁺ on the modified material followed a pseudo-second-order model, and the isotherms conformed to the Langmuir equation, indicating a monolayer chemical adsorption process. Moreover, after five adsorption-desorption cycles, the adsorbent demonstrated exceptional reusability and stability, and its potential for practical application preliminarily assessed using electroplating wastewater containing Ni²⁺. To further clarify the adsorption mechanism, a molecular dynamics simulation employing the CLAYFF-CVFF force field was conducted to examine the electrostatic interaction of modifiers at the clay surface. Wavefunction analyses derived from quantum chemical calculations provided insights into interactions, identified molecular reactive sites, and elucidated orbital interactions within chelation complexes. This research presents a feasible approach for developing high-performance materials for wastewater remediation in practical applications.

中文翻译：

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使用新型 2-羟基膦酰乙酸改性 Mg/Fe-LDH 复合吸附剂增强对废水中 Ni2+ 和 Co2+ 的去除


虽然处理电镀废水的技术不断进步，但去除高浓度的 Ni²⁺ 和 Co²⁺ 仍然是一个挑战。粘土的表面功能化已成为有效去除重金属的关键方法，其有效性可与插层改性相媲美。本研究研究了膦酸盐改性层状双氢氧化物材料的吸附性能和机理，采用批量实验和模拟计算来阐明表面改性对吸附行为的影响。简而言之，各种表征技术证实，通过共沉淀合成的层状双氢氧化物表现出片状形态，膦酸盐基团在功能化后锚定在粘土表面。在最佳条件下 （pH=6.0、t=60 min 和 C₀=300 mg/L），该材料对 Ni²⁺ （198.01 mg/g） 和 Co²⁺ （180.18 mg/g） 表现出高吸收能力，超过了以前报道的大多数吸附剂。Ni²⁺ 和 Co²⁺ 在改性材料上的吸附动力学遵循准二级模型，等温线符合 Langmuir 方程，表明单层化学吸附过程。此外，经过 5 次吸附-脱附循环后，吸附剂表现出优异的可重复使用性和稳定性，并使用含有 Ni²⁺ 的电镀废水初步评估了其实际应用潜力。为了进一步阐明吸附机制，采用 CLAYFF-CVFF 力场进行了分子动力学模拟，以检查改性剂在粘土表面的静电相互作用。 从量子化学计算中得出的波函数分析提供了对相互作用的见解，确定了分子反应位点，并阐明了螯合复合物内的轨道相互作用。本研究为开发用于废水修复的高性能材料在实际应用中提供了一种可行的方法。