A comprehensive study on paracetamol and ibuprofen adsorption onto biomass-derived activated carbon through experimental and theoretical assessments

The paper reports an experimental and theoretical work about the adsorption of paracetamol (PCM) and ibuprofen (IBP) onto a new activated carbon synthesized starting from the tree pods deriving from Erythrina speciosa. The adsorbent shows good porous properties, with a BET surface area of 795.1 m2/g, and an average pore volume of 0.422 cm3 g-1. Adsorption tests are carried out by varying the most important operating parameters. The adsorption capacity of both IBP and PCM results to be maximum at pH = 3, i.e., where the adsorbate molecules are found in neutral form. Adsorption isotherms indicated that IBP adsorption capacity increases with temperature up to 96.28 mg g-1, while an opposite trendwas retrieved for PCM, which decreased until 50.40 mg g-1. For a theoretical analysis, a double layer model (DLM) is adopted in order to provide an interpretation of the occurring adsorption mechanisms. The theoretical approach indicates that both IBP and PCM are adsorbed bya multi-molecular way, i.e. each functional group on the adsorbent surface accommodates more than one molecule at the same time. Finally, the adsorption energy reveals that a physical adsorption is responsible for both IBP and PCM adsorption on the synthesized adsorbent.

Automated summary

The paper presents experimental and theoretical research on the adsorption of paracetamol (PCM) and ibuprofen (IBP) on a new activated carbon derived from Erythrina speciosa tree pods. The adsorbent exhibits excellent porous properties with a BET surface area of 795.1 m2/g and an average pore volume of 0.422 cm3 g-1. The adsorption tests show that the maximum adsorption capacity of both IBP and PCM is achieved at pH = 3, where the adsorbate molecules are in their neutral form. The theoretical analysis suggests that both IBP and PCM are adsorbed through a multi-molecular mechanism on the surface of the adsorbent.