Zhang Chenxin, Chen Wei, Owens Gary, Chen Zuliang
Fujian Key Laboratory of Pollution Control and Resource Reuse, School of Environmental and Resource Sciences, Fujian Normal University, Fuzhou 350117, Fujian Province, China.
Environmental Contaminants Group, Future Industries Institute, University of South Australian, Mawson Lakes, SA 5095, Australia.
J Hazard Mater. 2024 Jun 5;471:134435. doi: 10.1016/j.jhazmat.2024.134435. Epub 2024 Apr 26.
There is increasing demand and interest in efficient methods for the recovery of rare earth elements (REEs) from wastewater because of the growing concerns associated with the negative impacts of REEs-rich waste discharged on pristine ecosystems. Here, we designed a ZIF-8@ALG composite hydrogel by encapsulating zeolitic imidazolate frameworks-8 (ZIF-8) into sodium alginate and poly (vinyl alcohol) double cross-linked networks (ALG) for the recovery of REEs from mine wastewater. ZIF-8@ALG showed exceptional REEs adsorption performance with the most superior separation factor (Ho/Mn) of 597.5. For the REEs considered, the ZIF-8@ALG composite exhibited a preference for heavy REEs with high adsorption efficiencies (65.3 ∼ 97.2%) and distribution coefficients (2045.5 ∼ 28500.0 mL·g). Adsorption involved a combination of electrostatic attraction, complexation and ion exchange mechanisms. REEs adsorbed on ZIF-8@ALG could also be desorbed using sodium citrate via ion-exchange and complexation, thus achieving efficient REEs recovery. In addition, ZIF-8@ALG was stable and reusable, maintaining effective adsorption in wastewater over four consecutive cycles, where the optimal adsorption efficiency reached 80.0%. Overall, this study provided an effective and feasible method for the recovery of REEs in mine wastewater, and confirmed that ZIF-8-based materials have significant potential for REEs recovery applications in wastewater engineering treatment.
由于人们越来越担心富含稀土元素的废物排放对原始生态系统产生负面影响，因此对从废水中回收稀土元素（REEs）的高效方法的需求和兴趣与日俱增。在此，我们通过将沸石咪唑酯骨架-8（ZIF-8）封装到海藻酸钠和聚乙烯醇双交联网络（ALG）中，设计了一种ZIF-8@ALG复合水凝胶，用于从矿山废水中回收稀土元素。ZIF-8@ALG表现出卓越的稀土元素吸附性能，其分离因子（Ho/Mn）高达597.5。对于所研究的稀土元素，ZIF-8@ALG复合材料对重稀土元素表现出偏好，具有较高的吸附效率（65.3% ∼ 97.2%）和分配系数（2045.5 ∼ 28500.0 mL·g）。吸附涉及静电吸引、络合和离子交换机制的组合。吸附在ZIF-8@ALG上的稀土元素也可以通过柠檬酸钠通过离子交换和络合作用进行解吸，从而实现稀土元素的高效回收。此外，ZIF-8@ALG稳定且可重复使用，在连续四个循环中保持对废水的有效吸附，最佳吸附效率达到80.0%。总体而言，本研究为矿山废水中稀土元素的回收提供了一种有效且可行的方法，并证实了基于ZIF-8的材料在废水工程处理中回收稀土元素的应用具有巨大潜力。
