Biblioteca Digital

Immersion enthalpies were determined for aqueous solutions of phenol, acetaminophen and water on three different carbons that differed in terms of oxygen groups on the surface. The intensity of the energy interaction between these compounds and the activated carbons was determined. The activated carbons had similar values for surface area and micropore volume, i.e. approximately 850 m².g-1 and 0.35 cm³.g-1, respectively, but differed in the content of surface chemical groups that interacted with the solutes in aqueous solution. The values obtained for the enthalpies of immersion of activated carbon in water were between -32 and -66 J.g-1. The enthalpies of immersion of activated carbon for acetaminophen and phenol solutions with concentrations between 100 mg.L-1 and 10 mg.L-1 were between -18 and -157 J.g-1, indicating greater interaction between the two solutes and activated carbons with a high surface content of reduced chemical groups