Shaopeng Zhang,Jie Ding,Dayong Tian,Jing Wang,Jiale Zhang,Minghua Lu
China faces severe antimony pollution due to long-term, high-intensity mining and smelting operations. Long-term exposure to Sb(III) can lead to chronic respiratory problems. Adsorption method is used to remove Sb(III) because of its simplicity, economy and high efficiency. Therefore, a novel MIL-101(Fe)-Cl/SA hydrogel with oxidation-sorption bifunctionality was developed. 1602 cm −1 and 1025 cm −1 correspond to N H and S = O indicate N-chlorosulfonamide is bonded to MIL-101(Fe)-Cl/SA. MIL-101(Fe)-Cl/SA exhibited rough and wrinkled surfaces with numerous irregular particles by SEM. The presence of O (22 %) and Cl (2 %) confirmed the incorporation of N-chlorosulfonamide and SA into MIL-101(Fe)-Cl/SA by EDS and mappings. The adsorption capacities of MIL-101(Fe)-Cl/SA were 86 mg/g at 298 K and 123.21 mg/g at 328 K by Langmuir model. Kinetic and equilibrium correspond to pseudo-second-order and Langmuir model, respectively. Adsorption was spontaneous and endothermic by thermodynamic analysis. MIL-101(Fe)-Cl/SA exhibited enhanced selectivity in solution containing various ions. Moreover, MIL-101(Fe)-Cl/SA demonstrated potential for regeneration and reuse. The removal process primarily involved oxidation, electrostatic interaction, and complexation. In summary, the capability of MIL-101(Fe)-Cl/SA to adsorb and oxidize Sb(III) underscores its promising potential in mitigating the hazards associated with Sb(III).
Porous modified polyacrylonitrile (PAN) with an ultrahigh percentage of amidoxime groups (UAPAN) was synthesized for the first time and used to adsorb antimonite (Sb(III)) and antimonate (Sb(V)) from aqueous solution. Fourier transform infrared (FT-IR), Zeta potential , X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) were adopted to characterize UAPAN and explore adsorption mechanism. Moreover, batch experiments were performed to investigate the influence of various adsorption parameters, including initial pH, contact time, temperature, coexisting ions and reusability on adsorption capacities. Results showed that the maximum adsorption capacities for Sb(III) and Sb(V) were 125.4 and 177.3 mg g −1 , respectively, which were much higher than those of other adsorbents reported in literature. The adsorption thermodynamics was evaluated, indicating the spontaneous and endothermic adsorption. The adsorption isotherm was suitable to be modeled by Langmuir isotherm ( R 2 > 0.96). Results of FT-IR, Zeta potential and XPS indicated that adsorption was involved with electric charge attraction and ligand exchange. DFT further explained that better adsorption of Sb(V) on UAPAN than that of Sb(III) was caused by the higher adsorption energy, more favorable bond lengths and atom charge density. Accordingly, UAPAN is expected to be a compelling candidate for antimony decontamination from aqueous environment.
危险品化学品经营许可证（带存储）