A kinetics, isotherms, and thermodynamic study of diclofenac adsorption using activated carbon prepared from olive stones

ABSTRACT

The objective of this work was to study the efficiency of activated carbon prepared from agricultural waste (olive stones; OS) on diclofenac (DCF) adsorption in aqueous solutions. The prepared charcoals were characterized by Fourier transform infrared (FTIR), scanning electron microscopy (SEM)/Energy Dispersive X-Ray Analyser (EDX), and Brunauer–Emmett–Teller (BET) analysis techniques. The results show that DCF adsorption is favorable in acid medium and low temperature. The adsorption kinetics follows a pseudo-second-order kinetic model. The adsorption was found to be spontaneous (ΔG° < 0) for OS600°C, whereas the negative values of the enthalpy (ΔH°) suggest an exothermic adsorption for both adsorbents.

GRAPHICAL ABSTRACT

KEYWORDS:

• Adsorption
• desorption
• isotherm
• kinetic