, Shaanxi Key Laboratory of Chemical Additives for Industry, Shaanxi University of Science and Technology, Xi'an, Shaanxi, 710021, PR China; , School of Chemistry and Bioengineering, Hechi University, Yizhou, Guangxi, 546300, PR China.
, Shaanxi Key Laboratory of Chemical Additives for Industry, Shaanxi University of Science and Technology, Xi'an, Shaanxi, 710021, PR China.
J Environ Manage. 2023 Jan 1;325(Pt B):116621. doi: 10.1016/j.jenvman.2022.116621. Epub 2022 Oct 31.
The adsorbents with recyclable, large adsorption capacity and selective adsorption can effectively remove the pollution and harm of heavy metal ions in water. Therefore, two magnetic composites containing sulfur (MCP-S4 and MCP-S8) on the hyper-branched surface were prepared, furthermore, their structures were characterized and adsorption performance was analyzed by FTIR, XRD, TGA, BET, SEM, TEM, VSM and ICP. The results showed that both MCP-S4 and MCP-S8 had superparamagnetism with saturation susceptibility of 22.10 and 22.26 emu/g, and owned a specific surface area of 11.394 and 11.235 m/g, respectively. MCP-S4 and MCP-S8 could selectively adsorb Hg with the exist of Fe, Cu, Co, Ni, Mn, and Al in solution. The adsorption kinetics accorded with pseudo-second-order model and Boyd film diffusion model, and the adsorption isotherm was fitted better with Langmuir isotherm model and D-R model, furthermore, the adsorption was an entropic-increasing and endothermic process. The removal rate of Hg from simulated sewage by the two materials was more than 91%, and the adsorption retention rate was more than 85% after five adsorption-desorption cycles. The adsorption mechanism was analyzed by comparing the changes of FTIR, EDS and XPS spectra before and after adsorption. It was found that functional groups (C-N, CONH, CS, SH) could form stable chelates with Hg, which was the main reason why MCP-S4 and MCP-S8 could adsorb Hg selectively, furthermore, S atoms of CS and -SH played a leading role in the process of adsorption. In addition, DFT calculation was also used as an auxiliary means to verify the adsorption mechanism.
具有可回收、高吸附容量和选择性吸附的吸附剂可以有效地去除水中重金属离子的污染和危害。因此，制备了两种具有超支化表面的含硫磁性复合材料（MCP-S4 和 MCP-S8），并通过 FTIR、XRD、TGA、BET、SEM、TEM、VSM 和 ICP 对其结构进行了表征和吸附性能分析。结果表明，MCP-S4 和 MCP-S8 均具有超顺磁性，饱和磁化强度分别为 22.10 和 22.26 emu/g，比表面积分别为 11.394 和 11.235 m/g。MCP-S4 和 MCP-S8 可以在溶液中存在 Fe、Cu、Co、Ni、Mn 和 Al 的情况下选择性地吸附 Hg。吸附动力学符合准二级动力学模型和 Boyd 膜扩散模型，吸附等温线更符合 Langmuir 等温模型和 D-R 模型，此外，吸附是一个熵增和吸热过程。两种材料从模拟废水中去除 Hg 的去除率均超过 91%，经过五次吸附-解吸循环后，吸附保留率均超过 85%。通过比较吸附前后 FTIR、EDS 和 XPS 谱图的变化，分析了吸附机理。结果表明，功能基团（C-N、CONH、CS、SH）可以与 Hg 形成稳定的螯合物，这是 MCP-S4 和 MCP-S8 能够选择性吸附 Hg 的主要原因，此外，CS 和 -SH 中的 S 原子在吸附过程中起主导作用。此外，还使用 DFT 计算作为辅助手段来验证吸附机理。
