Zwitterionic glycine modified Fe/Mg-layered double hydroxides for highly selective and efficient removal of oxyanions from polluted water

• 作者: Xiaofeng Shi Chao Wang Jiaoxia Zhang Li Guo Jing Lin Duo Pan Juying Zhou Jincheng Fan Tao Ding Zhanhu Guo
• 来源期刊: 材料科学技术（英文版）
• 年，卷（期）: 2020,（16）
• 页码范围: 8-15
• 页数: 8页
• 语种: 英文

摘要

Zwitterionic glycine was employed to modify Fe/Mg-layered double hydroxides (LDH) to realize an G-Fe/Mg-LDH adsorbent with high adsorption capacities of oxygen-containing anions including As(Ⅴ),P(Ⅴ)and Cr(Ⅵ).When the Fe/Mg mole ratio was 0.02 mol/0.02 mol,the G-Fe/Mg-LDH has a good adsorption performance.The optimum adsorption pH value of G-Fe/Mg-LDH for oxygen-containing anions was 6.The selectivity of three oxygen-containing anions was Cr(Ⅵ)＜P(Ⅴ)＜As(Ⅴ),and the maximum adsorption capacity of As(Ⅴ) reached as high as 830mgg-1,outperforming most previously reported efficient adsor-bents for As(Ⅴ).The adsorption process followed Freundlich isotherm and pseudo-second-order kinetic model,suggesting the heterogeneous adsorption and chemical adsorption of the G-Fe/Mg-LDH.When the initial concentration of As(Ⅴ) was 200 mg L-1,the adsorption efficiency of G-Fe/Mg-LDH was 82.5％within 30 min.This study provides a way to modify the LDHs for environmental remediation.