College of Chemistry and Material Science, Shandong Agricultural University, Taian, 271018, Shandong, People's Republic of China.
College of Life Sciences, Shandong Agricultural University, Taian, 271018, Shandong, People's Republic of China.
Environ Sci Pollut Res Int. 2021 Jun;28(24):32035-32045. doi: 10.1007/s11356-021-13028-z. Epub 2021 Feb 23.
In this paper, three-dimensional magnetic nitrogen-doped porous carbon modified by EDTA (N-MPC-EDTA) was successfully prepared by two-step method with lignin as the precursor, and was used for the removal of Cd (II). The 3D adsorbents were characterized by SEM, TEM, BET, XRD, XPS, Zeta potential, and element mapping analysis techniques, and the performance of the materials was tested by the batch adsorption method. The influence of experimental parameters such as contact time and pH value on the adsorption capacity of N-MPC-EDTA on Cd (II) was studied. Under the optimal conditions, the equilibrium adsorption capacity of Cd (II) was 43.68 mg∙ L and the adsorption equilibrium was quickly reached within 45 min. A possible adsorption mechanism was proposed, in which the chelation of EDTA as well as the electrostatic attraction of hydroxyl, carboxyl, and nitrogen-containing functional groups dominated the adsorption of Cd (II). The adsorption kinetics and isotherm data fitted well with the pseudo-second-order kinetic model and Freundlich model, respectively. In addition, the good regeneration performance suggested that N-MPC-EDTA will have a broad application prospect in water treatment.
本文以木质素为前驱体，采用两步法成功制备了三维磁性乙二胺四乙酸（EDTA）修饰的氮掺杂多孔碳（N-MPC-EDTA），并将其用于去除 Cd（II）。通过 SEM、TEM、BET、XRD、XPS、Zeta 电位和元素mapping 分析技术对 3D 吸附剂进行了表征，并通过批量吸附法测试了材料的性能。研究了接触时间和 pH 值等实验参数对 N-MPC-EDTA 对 Cd（II）吸附容量的影响。在最佳条件下，Cd（II）的平衡吸附容量为 43.68 mg·L，45 min 内即可快速达到吸附平衡。提出了一种可能的吸附机理，其中 EDTA 的螯合作用以及含羟基、羧基和含氮官能团的静电引力主导了 Cd（II）的吸附。吸附动力学和等温线数据分别与准二级动力学模型和 Freundlich 模型拟合良好。此外，良好的再生性能表明 N-MPC-EDTA 在水处理方面具有广阔的应用前景。
