Removal of 4-chloro-2-methylphenoxyacetic acid from water by MIL-101(Cr) metal-organic framework: kinetics, isotherms and statistical models

Hamza Ahmad Isiyaka; Khairulazhar Jumbri; Nonni Soraya Sambudi; Zakariyya Uba Zango; Bahruddin Saad; Adamu Mustapha

doi:10.1098/rsos.201553

Removal of 4-chloro-2-methylphenoxyacetic acid from water by MIL-101(Cr) metal-organic framework: kinetics, isotherms and statistical models

R Soc Open Sci. 2021 Jan 13;8(1):201553. doi: 10.1098/rsos.201553. eCollection 2021 Jan.

Authors

Hamza Ahmad Isiyaka¹, Khairulazhar Jumbri¹, Nonni Soraya Sambudi², Zakariyya Uba Zango¹, Bahruddin Saad¹, Adamu Mustapha³

Affiliations

¹ Fundamental and Applied Sciences Department, Universiti Teknologi PETRONAS, Bandar Seri Iskandar 32610, Perak Darul Ridzuan, Malaysia.
² Chemical Engineering Department, Universiti Teknologi PETRONAS, Bandar Seri Iskandar 32610, Perak Darul Ridzuan, Malaysia.
³ Department of Geography, Faculty of Earth and Environmental Science, Kano University of Science and Technology, Wudil, 3244 Kano Postal, Nigeria.

Abstract

Effective removal of 4-chloro-2-methylphenoxyacetic acid (MCPA), an emerging agrochemical contaminant in water with carcinogenic and mutagenic health effects has been reported using hydrothermally synthesized MIL-101(Cr) metal-organic framework (MOF). The properties of the MOF were ascertained using powdered X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, thermal gravimetric analysis (TGA), field emission scanning electron microscopy (FESEM) and surface area and porosimetry (SAP). The BET surface area and pore volume of the MOF were 1439 m² g^-1 and 0.77 cm³ g^-1, respectively. Artificial neural network (ANN) model was significantly employed for the accurate prediction of the experimental adsorption capacity (q_e ) values with minimal error. A rapid removal of the pollutant (99%) was recorded within short time (approx. 25 min), and the reusability of the MOF (20 mg) was achieved up to six cycles with over 90% removal efficiency. The kinetics, isotherm and thermodynamics of the process were described by the pseudo-second-order, Freundlich and endothermic adsorption, respectively. The adsorption process is spontaneous based on the negative Gibbs free energy values. The significant correlation between the experimental findings and simulation results suggests the great potential of MIL-101(Cr) for the remediation of MCPA from water matrices.

Keywords: MCPA; adsorption; artificial neural network; metal-organic framework; reusability.

Associated data

figshare/10.6084/m9.figshare.c.5253504