Department of Chemistry, Central Tehran Branch, Islamic Azad University, Tehran, Iran.
Department of Chemical Engineering, Faculty of Engineering, University of Tehran, Tehran, Iran.
Int J Biol Macromol. 2024 Oct;278(Pt 3):135003. doi: 10.1016/j.ijbiomac.2024.135003. Epub 2024 Aug 22.
The objective of this research was to develop and assess chitosan-grafted copolymer/HZSM5 zeolite Schiff base nanofibers for Cu and Zn adsorption from aqueous media. Nanofibers were prepared via electrospinning and characterized using XRD, FTIR, H NMR, FESEM, TGA, BET, and XPS. The study evaluated the effect of unmodified HZSM5 and Schiff base functionalization on adsorption capacities. Incorporating 10.0 wt% zeolite Schiff base as the optimum content into the chitosan-grafted copolymer significantly enhanced adsorption, achieving increases of 98.2 % for Zn and 42.2 % for Cu. Specifically, Zn adsorption increased from 27.6 to 54.7 mg/g, and Cu from 67.1 to 95.4 mg/g. Factors such as temperature, pH, adsorption time, and initial cation concentration were analyzed. Kinetic studies revealed a double-exponential model, and isotherm analysis indicated a good fit with the Redlich-Peterson model, showing maximum monolayer capacities of 310.1 mg/g for Cu and 97.8 mg/g for Zn (pH 6.0, 240 min, 45 °C). The adsorption thermodynamics indicated a spontaneous and endothermic adsorption. Reusability tests showed minimal capacity loss (4.91 % for Cu and 5.59 % for Zn) after five cycles. The nanofiber displayed greater selectivity for Cu over Zn in multi-ion systems and real electroplating wastewater, highlighting its potential for targeted heavy metal removal.
本研究旨在开发和评估壳聚糖接枝共聚物/HZSM5 沸石席夫碱纳米纤维，用于从水介质中吸附 Cu 和 Zn。纳米纤维通过静电纺丝制备，并通过 XRD、FTIR、H NMR、FESEM、TGA、BET 和 XPS 进行表征。该研究评估了未修饰的 HZSM5 和席夫碱功能化对吸附容量的影响。将 10.0wt%的沸石席夫碱作为最佳含量掺入壳聚糖接枝共聚物中，显著提高了吸附性能，Zn 的吸附率提高了 98.2%，Cu 的吸附率提高了 42.2%。具体而言，Zn 的吸附量从 27.6 增加到 54.7mg/g，Cu 的吸附量从 67.1 增加到 95.4mg/g。分析了温度、pH、吸附时间和初始阳离子浓度等因素。动力学研究表明符合双指数模型，等温线分析表明符合 Redlich-Peterson 模型，Cu 的最大单层容量为 310.1mg/g，Zn 的最大单层容量为 97.8mg/g（pH 6.0、240min、45°C）。吸附热力学表明是自发的吸热吸附。重复使用测试表明，在五个循环后，容量损失最小（Cu 为 4.91%，Zn 为 5.59%）。在多离子体系和实际电镀废水中，纳米纤维对 Cu 具有更高的选择性，对 Zn 则较低，这突出了其对目标重金属去除的潜力。
