He Li-Ting, Zhao Liang-Dong, Sun Wei, Fang Jing, Liu Xiu-Wu, Qi Jun-Jie, Qian Yong, Li Hao
National-Local Joint Engineering Laboratory for Energy Conservation in Chemical Process Integration and Resources Utilization, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300401, China.
State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640, China.
Langmuir. 2023 Oct 31;39(43):15319-15327. doi: 10.1021/acs.langmuir.3c02129. Epub 2023 Oct 17.
Adsorption is an effective method for the treatment of heavy metal ions in water; however, the existing adsorbents are complicated to prepare, and costly and difficult to recover. In this work, a 3D wood microfilter was prepared by modifying wood for the removal of heavy metal contaminants from water. First, a green deep eutectic solvent was used to remove lignin from beech wood. Then citric acid and l-cysteine were sequentially used to graft carboxyl and sulfhydryl groups (-SHs) on the surface of cellulose. Finally, a three-dimensional wood microfilter with an abundant porous structure and adsorption sites was formed. The adsorption kinetics and adsorption isotherms of heavy metal ions on the 3D wood microfilter were systematically investigated using Cu and Cd as model species. The results showed that the 3D wood microfilter had a fast adsorption rate and high saturation capacity for both Cu and Cd. Based on the advantages of easy processing and multilayer assembly and stacking, a three-layer wood microfilter was designed to achieve high flux rate (1.53 × 10 L m h) and high efficiency (>98%) for the removal of heavy metal ions in water. The enhancement mechanism of the adsorption process of Cu and Cd by the 3D wood microfilter was investigated using SEM and EDS, FTIR, and XPS characterization. The simple synthesis method and high adsorption efficiency of this wood microfilter provide a new strategy for the preparation of cheap, efficient, and recyclable adsorbents for heavy metal ions in water.
吸附是处理水中重金属离子的有效方法;然而,现有的吸附剂制备复杂、成本高且难以回收。在本研究中,通过对木材进行改性制备了一种三维木材微滤器,用于去除水中的重金属污染物。首先,使用绿色低共熔溶剂去除山毛榉木材中的木质素。然后依次使用柠檬酸和L-半胱氨酸在纤维素表面接枝羧基和巯基(-SHs)。最后,形成了具有丰富多孔结构和吸附位点的三维木材微滤器。以铜和镉为模型物种,系统研究了重金属离子在三维木材微滤器上的吸附动力学和吸附等温线。结果表明,三维木材微滤器对铜和镉都具有快速的吸附速率和高饱和容量。基于易于加工以及多层组装和堆叠的优点,设计了一种三层木材微滤器,以实现高通量率(1.53×10 L m h)和高效(>98%)去除水中的重金属离子。利用扫描电子显微镜和能谱分析、傅里叶变换红外光谱以及X射线光电子能谱表征研究了三维木材微滤器对铜和镉的吸附过程增强机制。这种木材微滤器简单的合成方法和高吸附效率为制备用于水中重金属离子的廉价、高效且可回收的吸附剂提供了一种新策略。