Adsorption of organic compounds from aqueous solution by pyridine-2-carboxaldehyde grafted MIL-101(Cr)-NH2 metal-organic frameworks. Issue 4 (August 2021)

• Record Type: Journal Article
• Authors: Dapaah, Malcom Frimpong; Liu, Baojian; Cheng, Liang
• Is Part Of: Journal of environmental chemical engineering. Volume 9:Issue 4(2021)
• Publication Date: 2021-08
• Subjects: MIL-101-N-2-pyc -- Kinetics -- Isotherm studies -- BPA -- Regeneration; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2021.105275
• Languages: English
• ISSNs: 2213-2929

Abstract

Abstract: Metal-organic frameworks (MOFs) are of particular interest in the adsorption of organic pollutants. This study investigated the adsorption of aniline (ANI), furfural (FUR), and bisphenol A (BPA) in aqueous solution using MIL-101(Cr)-X (X = –H, –NO2, –NH2 and, –N-2-pyc), MIL-100(Cr, Fe), HKUST-1, and ZIF-8. For the first time, an imino-functionalized MOF was used to adsorb organic compounds in water. MOFs were characterized by XRD, N2 adsorption-desorption, SEM, TEM, elemental analysis, and FTIR. MIL-101-N-2-pyc demonstrated the highest adsorption capacity of 460.8, 126.5, and 100.7 mg/g towards 500 mg/L BPA, ANI, and FUR respectively. The adsorption isotherms better suited the Langmuir model than the Freundlich model. Importantly, 98% of BPA (100 mg/L) was removed and the kinetic data correlated well with the pseudo-second-order model (R 2 > 0.998). Binary adsorption of FUR and acetic acid (AA) were determined for industrial relevance. MIL-101-N-2-pyc outperformed commercial activated carbon and the other MIL-101s with an impressive co-adsorption of 66.1 mg/g FUR and 62.5 mg/g AA. Overall, the adsorption mechanism was due to hydrogen bonding, π-π interaction, and electrostatic attraction. Moreover, MIL-101-N-2-pyc exhibited remarkable structural stability and less than 0.01 wt% Cr leached into water. The adsorbent regeneration was improved after 4 cycles in methanol. Graphical Abstract: ga1 Highlights: Imine modification of MIL-101(Cr) for aqueous adsorption was conducted. The maximum adsorption capacity of BPA was 564 mg/g. The adsorption mechanism was elaborated. Binary adsorption of furfural and acetic acid was evaluated.