Adsorption of paracetamol and ketoprofenon activated charcoal prepared from the residue of the fruit of Butiacapitate: Experiments and theoretical interpretations

• A new adsorbent was prepared from the residue of Butiacapitate. • The adsorption of pharmaceutical molecules was studied. • Adsorption of ketoprofen was endothermic, while paracetamol was exothermic. • A double-layer model with two energies deriving from statistical physics was applied. • This study highlights the important aspects of the adsorption mechanism. This paper describes the removal process via adsorption of paracetamol (PRC) and ketoprofen (KTP) on activated charcoal prepared from the residue of the fruit of Butiacapitate. Some adsorbent characterizations are carried out for a plausible analysis of the adsorption results and for the description of adsorption mechanism. Modelling investigations show that the double layer derived from statistical physiscs can be adopted to interpret the adsorption data. Interestingly, the adsorption mechanism can be elucidated via the model parameters determined at different temperatures. The performance of the adsorbent in terms of maximum adsorption capacity increased from 101.16 to 134.52 mg/g for KTP molecules and decreased from 98.19 to 73 mg/g for PRC molecules, by increasing the temperature, which are in line with the experimental values retrieved. These tendencies of adsorption capacities may be related to the behavior of the number of PRC and KTP pharmaceuticals captured per functional group of the adsorbent. Overall, the modeling results show also that the values of adsorption energies associated to the two layers of KTP and PRC molecules on the adsorbent surface are lower than 40 kJ/mol, implying that only physical type interactions occur in the removal process of these pharmaceutical molecules.