Adsorption of diclofenac from aqueous solution using Cyclamen persicum tubers based activated carbon (CTAC)

This study aims to use the tissues of Cyclamen persicum tubers to prepare activated carbon (CTAC) by different methods then to set up a thermodynamic study of the pharmaceutical diclofenac sodium (DCF) adsorption from aqueous solution onto this activated carbon. Optimum percent of DCF removal was 72% when CTAC dosage was 0.25 g and DCF concentration 50 mg/L. Percentage removal of DCF increases when the concentration of DCF increases as the maximum percentage removal reached 81% when DCF concentration was 70 mg/L and 0.7 g CTAC and pH ranging from 6 to 2.Freundlich model describes efficiently adsorption isotherm of DCF onto CTAC with n equal to 1.398 whose value indicates a favorable adsorption. This finding validates the assumption of multilayer physical adsorption process of DCF. The results showed that DCF was physically adsorbed onto CTAC, as confirmed by the values of ΔH° minor than 40 kJ/mol. As ΔG° had negative charge, the adsorption process is exothermic, and the adsorption process of the DCF onto CTAC is spontaneous, depending on temperature.