College of Civil Engineering, Hunan University of Technology, Zhuzhou, Hunan 412007, China; National & Local Joint Engineering Research Center for Advanced Packaging Material and Technology, Hunan University of Technology, Zhuzhou, Hunan 412007, China.
College of Civil Engineering, Hunan University of Technology, Zhuzhou, Hunan 412007, China.
Int J Biol Macromol. 2024 Oct;278(Pt 3):135000. doi: 10.1016/j.ijbiomac.2024.135000. Epub 2024 Aug 22.
High adsorption capacity, high adsorption rate and reusable adsorbents are urgent needed for removing heavy metals from wastewater. In this study, porous sodium alginate/cellulose nanofiber (SA/CNF) composite hydrogel microspheres were prepared by combining sodium alginate with cellulose nanofibers by microfluidics technology and adding polyethylene glycol (PEG) as pore making agent. The SA/CNF composite hydrogel microspheres could efficiently adsorb heavy metals (Pb, Cu and Cd) in wastewater. The influencing factors of adsorption process, including pH, temperature, initial concentration, coexisting ions and aquatic environments, were systematically discussed. The adsorption process was more consistent with Langmuir isotherm model and pseudo-second-order model in batch system, indicating the adsorption process was mainly chemical adsorption. The adsorption capacity to Pb obtained by Langmuir model was as high as 544.66 mg/g at 20 °C. Fixed-bed column adsorption experiments demonstrated the excellent performance of the as-prepared SA/CNF microspheres for treatment of the flowing wastewater in a column system. Overall, a highly practical adsorption process based on hydrogel adsorbents was developed for the removal of heavy metals from actual wastewater.
从废水中去除重金属，迫切需要高吸附容量、高吸附速率和可重复使用的吸附剂。在这项研究中，通过微流控技术将海藻酸钠与纤维素纳米纤维结合，并添加聚乙二醇（PEG）作为造孔剂，制备了多孔海藻酸钠/纤维素纳米纤维（SA/CNF）复合水凝胶微球。SA/CNF 复合水凝胶微球可以有效地吸附废水中的重金属（Pb、Cu 和 Cd）。系统地讨论了吸附过程的影响因素，包括 pH 值、温度、初始浓度、共存离子和水相环境。在批处理系统中，吸附过程更符合 Langmuir 等温吸附模型和准二级动力学模型，表明吸附过程主要是化学吸附。在 20°C 下，Langmuir 模型得到的对 Pb 的吸附容量高达 544.66mg/g。固定床柱吸附实验表明，所制备的 SA/CNF 微球在柱系统中对处理流动废水具有优异的性能。总之，开发了一种基于水凝胶吸附剂的高效实用的吸附工艺，用于去除实际废水中的重金属。
