Fabrication of novel 3D PEI-functionalized ZIF-8@alginate aerogel composites for efficient elimination of Pb(II) and Cd(II) from aqueous solution

• Published in: Journal of environmental chemical engineering Vol. 11; no. 5; p. 110446
• Main Authors: Guo, Zhiqiang, Hou, Hui, Zhou, Jian, Wu, Xinmiao, Li, Yuan, Hu, Liangliang
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2023
• Subjects: Aerogel; Heavy metals; Sodium alginate; Sorption performance; ZIF-8; Sorption performance; Sodium alginate; ZIF-8; Aerogel; Heavy metals
• ISSN: 2213-3437; 2213-3437
• DOI: 10.1016/j.jece.2023.110446

ZIF-8, a metal-organic framework, has large sorption capacities for a series of heavy metals. However, it is difficult to be separated from aqueous solution, limiting its practical application in wastewater treatment. Herein, ZIF-8 was in-situ grown on the polyethyleneimine-functionalized alginate to construct the ZIF-8 @ALG-PEI aerogels with a three-dimensional network structure. This synthesis strategy not only overcomes the above-mentioned defects of ZIF-8, but also provides more functional groups, pores, and channels. The synthesized ZIF-8 @ALG-PEI aerogels exhibit outstanding removal performance towards Pb(II) and Cd(II) with maximum sorption capacity values of 295.986 and 249.838 mg·g−1, respectively. The sorption of Pb(II) and Cd(II) on ZIF-8 @ALG-PEI is strongly affected by pH, but little influenced by ionic strength. In the multi-component sorption systems, ZIF-8 @ALG-PEI shows better sorption affinity and selectivity for Pb(II) than for Cd(II). The three-dimensional network structure constructed by alginate makes Pb(II) and Cd(II) easier to contact with the surfaces of ZIF-8 @ALG-PEI. The strong surface complexation of the O- and N-containing functional groups provided by ZIF-8 and PEI with Pb(II) and Cd(II) makes the largest contribution to the removal of Pb(II) and Cd(II) by ZIF-8 @ALG-PEI. In summary, the experimental findings of this work prove that the synthesized ZIF-8 @ALG-PEI aerogels have promising applications in practical wastewater treatment. [Display omitted] •ZIF-8 @ALG-PEI aerogels with a three-dimensional network structure were prepared.•ZIF-8 @ALG-PEI aerogels overcome the drawback that ZIF-8 is difficult to recover.•The introduction of ZIF-8 and PEI provides a large number of functional groups.•ZIF-8 @ALG-PEI aerogels exhibit excellent sorption properties for Pb(II) and Cd(II).•ZIF-8 @ALG-PEI aerogels have promising applications in actual wastewater treatment.