Chaurasiya Arbind, Pande Poorn Prakash, Shankar Ravi, Khare Prateek, Kashaudhan Kopal
Department of Chemistry and Environmental Science, Madan Mohan Malaviya University of Technology, Gorakhpur 273010, Uttar Pradesh, India.
Department of Chemistry and Environmental Science, Madan Mohan Malaviya University of Technology, Gorakhpur 273010, Uttar Pradesh, India.
Int J Biol Macromol. 2025 Jun;311(Pt 2):143594. doi: 10.1016/j.ijbiomac.2025.143594. Epub 2025 May 2.
This study investigated the elimination of Co, Ni and Cu ions from water using a mesoporous, cost-effective, reusable, biodegradable and efficient xanthan gum xanthate-based hydrogel (XGmXHs hydrogel) as an adsorbent. The XGmXHs hydrogel was prepared via free radical polymerization process with varying the ratios of 2-hydroxyethyl methacrylate (HEMA) and acrylic acid (AA) as monomers. These ratios were optimized based on grafting efficiency, swelling capacity and point of zero charge (ΔpH) analysis. The results demonstrate that the XGmXHs hydrogel containing copolymer of HEMA: AA in a 1:3 ratio is optimal for grafting on xanthan gum (XGm) during polymerization process. The 1:3 ratio of monomer grafted on xanthan gum xanthate (XGmX) is referred to as XGmXHs-3 hydrogel. The XGmXHs-3 hydrogel showed a consistently negative surface charge across a diverse pH range, resulting the AA content was enhanced. Consequently, the swelling and adsorption capacity of the XGmXHs-3 hydrogel is significantly high. The optimum swelling capacity of the XGmXHs-3 hydrogel was found 40,128 % in water at pH 11. The maximum removal efficiency was 92.21 % for Co, 95.45 % for Ni and 98.30 % for Cu ions at pH 7. According to isothermal studies, the adsorption data aligns most closely with Langmuir isotherm model, resulting the adsorption capacities of 358.42, 469.48 and 555.55 mg/g Co, Ni and Cu ions, respectively. The adsorption kinetics were consistent with a pseudo-first-order kinetic model, showing rate constant of -2.6 × 10, -4.0 × 10 and - 6.3 × 10 min for Co, Ni and Cu ions, respectively. The desorption efficiencies were 64.76 % for Co, 68.83 % for Ni and 72.11 % for Cu ions to the XGmXHs-3 hydrogel after being regenerated for the fifth cycle.
本研究考察了一种介孔、经济高效、可重复使用、可生物降解且高效的基于黄原胶黄原酸酯的水凝胶（XGmXHs水凝胶）作为吸附剂对水中钴、镍和铜离子的去除效果。XGmXHs水凝胶通过自由基聚合工艺制备，以甲基丙烯酸羟乙酯（HEMA）和丙烯酸（AA）作为单体，改变二者比例。基于接枝效率、溶胀能力和零电荷点（ΔpH）分析对这些比例进行了优化。结果表明，在聚合过程中，含1:3比例HEMA:AA共聚物的XGmXHs水凝胶最适合接枝到黄原胶（XGm）上。接枝到黄原胶黄原酸酯（XGmX）上的1:3比例单体被称为XGmXHs - 3水凝胶。XGmXHs - 3水凝胶在不同pH范围内表面电荷始终为负，这使得AA含量增加。因此，XGmXHs - 3水凝胶的溶胀和吸附能力显著提高。XGmXHs - 3水凝胶在pH为11的水中的最佳溶胀能力为40128%。在pH为7时，对钴离子的最大去除效率为92.21%，对镍离子为95.45%，对铜离子为98.30%。根据等温线研究，吸附数据与朗缪尔等温线模型最为吻合，钴、镍和铜离子的吸附容量分别为358.42、469.48和555.55 mg/g。吸附动力学符合准一级动力学模型，钴、镍和铜离子的速率常数分别为 - 2.6×10、 - 4.0×10和 - 6.3×10 min。在第五次循环再生后，XGmXHs - 3水凝胶对钴离子的解吸效率为64.76%，对镍离子为68.83%，对铜离子为72.11%。
