Zeng Xiangchu, Zhang Guanghua, Wu Zhe
Shaanxi Key Laboratory of Chemical Additives for Industry, Shaanxi University of Science and Technology, Xi'an, 710021, Shaanxi, China.
Environ Sci Pollut Res Int. 2022 Apr;29(20):30324-30336. doi: 10.1007/s11356-021-17949-7. Epub 2022 Jan 8.
A FeO hybrid material (FeO@SiO-S) modified by Schiff-base was prepared by grafting methyl acrylate (MA), ethylenediamine (EDA), and salicylaldehyde (SA) to the prepared magnetic hybrid material (FeO@SiO-NH) successively; what's more, the structure was characterized by FTIR, XRD, SEM, TEM, and VSM. The results showed that the FeO@SiO-S has an obvious core-shell structure and a saturation magnetization of 45.9 emu/g. Study on the adsorption of aqueous heavy metal ions showed that FeO@SiO-S posed selective adsorption for Hg with the saturated adsorption capacity of 362 mg/g (1.12 mmol/g), which was superior to FeO@SiO-NH, FeO@SiO-HO-S, and other adsorbents, at the condition of pH = 6, 45℃, the adsorption capacity remained 89% after 5 cycles of adsorption-desorption; what is more, adsorption equilibrium was reached at about 300 min, and the adsorption isotherm conformed to the Langmuir isotherm adsorption model; in addition, pseudo-second-order model could be well described the adsorption kinetic process of FeO@SiO-S to Hg. The adsorption mechanism demonstrated that the N atoms of Schiff-base were mainly contributed to the adsorption of Hg; what is more, the N atom of tertiary amine and the O atoms of hydroxy and carbonyl also help to the adsorption of Hg.
通过将丙烯酸甲酯（MA）、乙二胺（EDA）和水杨醛（SA）依次接枝到制备好的磁性杂化材料（FeO@SiO-NH）上，制备了一种经席夫碱修饰的FeO杂化材料（FeO@SiO-S）；此外，通过傅里叶变换红外光谱（FTIR）、X射线衍射（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）和振动样品磁强计（VSM）对其结构进行了表征。结果表明，FeO@SiO-S具有明显的核壳结构，饱和磁化强度为45.9 emu/g。对水溶液中重金属离子的吸附研究表明，在pH = 6、45℃的条件下，FeO@SiO-S对Hg具有选择性吸附，饱和吸附容量为362 mg/g（1.12 mmol/g），优于FeO@SiO-NH、FeO@SiO-HO-S等吸附剂，经过5次吸附-解吸循环后，吸附容量仍保持89%；此外，在约300 min时达到吸附平衡，吸附等温线符合朗缪尔等温吸附模型；另外，准二级模型能够很好地描述FeO@SiO-S对Hg的吸附动力学过程。吸附机理表明，席夫碱的N原子主要对Hg的吸附有贡献；此外，叔胺的N原子以及羟基和羰基的O原子也有助于Hg的吸附。
