Estudio experimental y modelado teórico basado en DFT de la eliminación de ceftriaxona por carbón activado sintetizado a partir de residuos de semillas de uva

An activated carbon (AC) developed from grape seeds waste was characterized using various physico-chemical techniques to assess its structural and textural properties, then used for the removal of ceftriaxone (CFTX), an emerging pollutant, from aqueous solutions. Batch adsorption experiments were conducted, coupled with a theoretical study based on DFT (density functional theory) study , performed at the B3LYP level with a 6-311G (d,p) base , in order to study molecular geometries, electronic properties and molecular electrostatic potentials, to clarify the adsorption mechanism of CFTX on AC. The results revealed that the prepared AC had a well-established porosity offering a large exchange surface. Adsorption studies revealed that kinetic data aligned well with the PSO model, while equilibrium data were best described by the Freundlich isotherm and the multilayer STAT₁ model. Thermodynamic analysis indicated endothermal and favorable adsorption, mainly controlled by chemical interactions. Moreover, the regeneration studies showed the difficult desorption of CFTX, supporting a chemisorption mechanism. The results of DFT calculations indicated that the adsorption of CFTX is favorable on AC functionalized with -CHO and -COOH-OH-CHO, with adsorption energies of - [Formula: see text] and - [Formula: see text], respectively. AIM (atoms in molecules), NCI (non-covalent interactions) and RDG (reduced density gradient) analyses revealed that strong hydrogen-bond interactions mainly govern the adsorption mechanism. According to the obtained results, the produced AC is considered as a high-performance alternative material for the removal of CFTX from aqueous environments. In addition, a thorough understanding of the adsorption process resulted from integrating theoretical and experimental approaches.