Regenerable zeolitic imidazolate frameworks@agarose (ZIF-8@AG) composite for highly efficient adsorption of Pb(II) from water

• Published in: Journal of solid state chemistry 2022-03, Vol.307, p.122823, Article 122823
• Main Authors: Fu, Qiuping, Zhou, Shaoqi, Wu, Pan, Hu, Jing, Lou, Jie, Du, Bin, Mo, Changli, Yan, Wei, Luo, Jun
• Format: Article
• Language: English
• Subjects: Adsorption; Pb(II); Regeneration; Water treatment; ZIF-8@AG
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1016/j.jssc.2021.122823

The composite zeolitic imidazolate frameworks@agarose (ZIF-8@AG) was prepared by ZIF-8 and agarose (AG) in this study. The composite ZIF-8@AG with a good quality, was assessed for Pb(II) adsorption and regeneration from water. The effects of the contact time, initial concentration of Pb(II), adsorbent dosage, pH, coexisting ions (Ca2+ and Mg2+), temperature and other factors on the adsorption performance of Pb(II) on ZIF-8@AG were investigated. The pseudo-second-order kinetic model can well describe the adsorption process of Pb(II) on ZIF-8@AG. Thermodynamic parameters (ΔG, ΔH and ΔS) confirmed exothermic and spontaneous process. In the regeneration experiment, ZIF-8@AG maintained a high adsorption capacity for Pb(II) after 6 times of adsorption-desorption cycles. The experimental results showed that the ZIF-8@AG not only has a high adsorption efficiency for Pb(II), but also has a good stability for recycling. The composite ZIF-8@AG has a good quality and can effectively remove Pb(II) in the initial concentration range of 10–100 ​mg/L. The ZIF-8@AG showed excellent removal efficiency and regeneration ability for Pb(II). [Display omitted] •Compared with pure ZIF-8, ZIF-8 wrapped in AG can overcome the problems of secondary pollution caused by the easy dispersion of powdered ZIF-8 in water and the difficulty in separating from water.•The adsorption process of Pb(II) on ZIF-8@AG is dominated by chemical adsorption.•The removal efficiency of Pb(II) by ZIF-8@AG remains more than 92.67% after 6 times of regeneration of ZIF-8@AG.