College of Chemistry, Zhengzhou University, No 100 of Kexue Road, Zhengzhou 450001, China.
Center for modern analysis and gene sequencing, Zhengzhou University, No 100 of Kexue Road, Zhengzhou 450001, China.
Int J Biol Macromol. 2021 Jul 1;182:1759-1768. doi: 10.1016/j.ijbiomac.2021.05.116. Epub 2021 May 25.
In this study, zirconium (IV)-impregnated magnetic chitosan graphene oxide (Zr-MCGO) was synthesized for removing fluoride from aqueous solution in batch mode. Characterization approaches (pH, FTIR, SEM, XRD, VSM, Raman, BET, and XPS) proved the successful incorporation of Zr into the adsorbent. Zr-MCGO exhibited a relatively favorable and stable capacity of defluoridation at lower pH with a wide range of pH from 4.0 to 8.0, while there was slightly negative effect of ionic strength on adsorption. In addition, Elovich kinetic model and Koble-Corrigan isotherm model could describe the uptake of fluoride well. The adsorption capacity was 8.84 mg/g at 313 K and Zr-MCGO was easily separated from mixtures using external magnet. Based on the experiments and XPS, electrostatic force, ligand exchange, and Lewis acid-base interaction might be potential adsorption mechanisms. Pseudo-second-order model was more compatible with the desorption process by 0.01 mol/L NaHCO solution. Therefore, Zr-MCGO was a promising candidate for defluoridation on wastewater pollution remediation.
在这项研究中，合成了负载锆（IV）的磁性壳聚糖石墨烯氧化物（Zr-MCGO），用于批量模式从水溶液中去除氟化物。采用各种表征方法（pH、FTIR、SEM、XRD、VSM、Raman、BET 和 XPS）证明了Zr 成功负载到吸附剂上。Zr-MCGO 在较低 pH 值（4.0-8.0）下具有相对较好和稳定的除氟能力，而离子强度对吸附的影响较小。此外，Elovich 动力学模型和 Koble-Corrigan 等温线模型能够很好地描述氟化物的吸附。在 313 K 时，吸附容量为 8.84 mg/g，Zr-MCGO 可以很容易地通过外部磁场从混合物中分离出来。基于实验和 XPS 结果，静电引力、配体交换和路易斯酸碱相互作用可能是潜在的吸附机制。用 0.01 mol/L NaHCO3 溶液进行解吸时，准二级模型更适合解吸过程。因此，Zr-MCGO 是一种很有前途的废水污染修复除氟剂。
