Adsorption of diclofenac on mesoporous activated carbons: Physical and chemical activation, modeling with genetic programming and molecular dynamic simulation
This research project was submitted to Ilam University of Medical Sciences, Ilam, Iran (Grant No.: 99R001/25). The authorswould like to thank Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
This work aims at the preparation of AC from chemical activation (H3PO4, KOH, and HCl)and physical activation (thermal treatment under N2atmosphere at 500 and 700◦C) of Astra-galus Mongholicus (AM) (a low-cost bio-adsorbent and agro-industrial waste), used as carbonprecursor. The obtained materials were further applied in the adsorption of diclofenac(DCF) from water/wastewater. The physicochemical properties of the as-prepared ACs andcommercial activated carbons (CAC) were evaluated by SEM, XRD, FT-IR, and BET analyses,revealing the high surface area and mesoporous proportion of AC when compared to CAC. Adsorption results showed that the efficiency of AC-700◦C (774 m2g−1) for DCF removal(92.29%) was greater than that of AC-500◦C (648 m2g−1, 83.5%), AC-H3PO4(596 m2g−1, 80.8%),AC-KOH (450 m2g−1, 59.3%), AC-HCl (156 m2g−1, 29.8%) and CAC (455 m2g−1, 67.8%). The opti-mization of effective parameters in adsorption was examined at a laboratory-scale using theselected AC-700◦C. The Langmuir isotherm and the pseudo-second-order model fitted wellthe experimental data. The regeneration efficiency was maintained at 96% (DI-water) and97% (heating) after three cycles. Besides, genetic programming (GP) and molecular dynam-ics (MD) simulations were applied to predict the adsorption behavior of DCF from aqueousphase as well as in the ACs structure. It was found that the adsorption mechanisms involvedwere electrostatic interaction, cation–pi interaction, and pi–pi electron interaction.
