1. Metal selectivity and effects of co-existing ions on the removal of Cd, Cu, Ni, and Cr by ZIF-8-EGCG nanoparticles
- Author
-
Jia Wen and Xiaohong Hu
- Subjects
chemistry.chemical_element ,Nanoparticle ,02 engineering and technology ,Epigallocatechin gallate ,010402 general chemistry ,01 natural sciences ,Ion ,Biomaterials ,Metal ,chemistry.chemical_compound ,symbols.namesake ,Colloid and Surface Chemistry ,Adsorption ,Chemistry ,Langmuir adsorption model ,021001 nanoscience & nanotechnology ,Copper ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,visual_art ,visual_art.visual_art_medium ,symbols ,0210 nano-technology ,Selectivity ,Nuclear chemistry - Abstract
Recently, the developments of MOFs and their applications on heavy metal removal have attracted much attention. In this paper, we focused on the influence of co-existing ions on the adsorbability of epigallocatechin gallate (EGCG) modified ZIF-8 in a multi-metal system (Cd(II), Cu(II), Ni(II), and Cr(VI)). It was found that the adsorption of Cd(II), Cu(II), Ni(II), and Cr(VI) on the ZIF-8-EGCG fitted well with the pseudo second-order kinetic model and Langmuir isotherm. The adsorption selectivity of ZIF-8-EGCG in the mixed metal solution followed the order of Cu(II) ≫ Cr(VI) > Cd(II) > Ni(II). Besides, Cu(II) was the most attractive substance with a maximum capacity of 232.97 mg·g−1. Copper also disturbed the adsorption of Cd(II) and Ni(II) and contributed the most to the Cr(VI) removal. The natural anions (e.g., Cl−, NO3–, AsO2−, SO42−) significantly impeded Cr(VI) adsorption, while low concentrations of natural cations (e.g., K+, Na+, Ca2+, and Mg2+) facilitated the adsorption of Cd(II), Cu(II) and Ni(II).
- Published
- 2021