Efficient removal of 2,4-dichlorophenol from aqueous solution using UiO‑66 metal–organic framework: isotherm and kinetics studies

Abstract

ABSTRACT In this research, Uio-66 as a metal-organic framework (MOF) was synthesised and the feasibility of using this adsorbent was investigated to remove 2,4- dichlorophenol (2,4-DCP) from aqueous environments under experimental conditions. The structure and properties of the UiO-66 were characterised by scanning electron microscope (SEM), Fourier transform infrared (FTIR), and X-Ray diffraction (XRD). The crystallite size of UiO-66 was found to be 26.80 nm using XRD analysis. Different adsorption conditions, such as pH (3–8), contact time (10–90 min), the adsorbent dosage (0.01–0.2 g), the initial concentration (0.05–30 mg/L), and temperature (25–60°C) effects were evaluated. The maximum removal efficiency was obtained at a pH of 5, contact time of 60 min, adsorbent dosage of 0.1 g, initial concentration of 10 mg/L, and a temperature of 25°C. The adsorption data fitted the Langmuir isotherm model well (R2 = 0.9932), which indicated a maximum adsorption capacity (qmax) of 34.01. The pseudo-second-order (PSO) model described the kinetic experimental data with a coefficient of determination (R2) equal to 0.9968. Furthermore, UiO-66 revealed excellent structural stability and reusability after 5 cycles of adsorption experiments. The removal efficiency ranges related to the analysis of Forty-Herbs honey as a real sample were 80.66%–99.70%. The high adsorption capacity, and inexpensive and facile preparation made Uio-66 as an ideal adsorbent for removing 2,4-DCP from aqueous solution.