Enhancement of the heterogeneous adsorption and incorporation of uraniumVI caused by the intercalation of β-cyclodextrin into the green rust
2021
Huang, Tao | Su, Zhiyu | Dai, Yuxing | Zhou, Lulu
The influence of intercalated anions on the structure and composition of green rusts supplies a theoretical possibility for the investigation of the structural modification of Feᴵᴵ/Feᴵᴵᴵ (oxyhydr)oxide materials. β-Cyclodextrin was intercalated into the mixed-valent iron-based hydroxide layers to synthesize new green rust materials (β-CD GRs), pursuing high-capacity uraniumⱽᴵ (Uⱽᴵ) sorption. The molar ratios of Feᴵᴵ to Feᴵᴵᴵ and the molar ratios of β-CD GR to Feᴵᴵ + Feᴵᴵᴵ had a significant effect on the synthesis of β-CD GRs. The synthesis process was further optimized by the quadric predictor and desirability function in a central composite design in combination. Both strong acidity and alkalinity were harmful to the adsorption of β-CD GRs towards Uⱽᴵ. The pseudo-first-order kinetic model and Langmuir isotherm model were appropriate in fitting the whole adsorption process. The maximum monolayer adsorption capacity of β-CD GRs was 2548.61 mg/g. The presence of mimic groundwater constituents explicitly deteriorated the interaction between β-CD GR and Uⱽᴵ species. Nanoscale nodules and particles were formed on the β-CD GR after the adsorption experiments. The peaks at 1159 and 609 cm⁻¹ vanished with the band at 1103 cm⁻¹ being left-shifted to 1117 cm⁻¹ in the FTIR spectra of β-CD GR during the heterogeneous process. The intercalation of β-CD brought obvious enhancement of Uⱽᴵ species sorption to the GR material, which was combinedly driven by several reaction pathways and different from the unmodified GRs.
显示更多 [+] 显示较少 [-]