Removal of acetylsalicylic acid (Asa) in packed microcolumns with carbon xerogel modified with TiO₂ nanoparticles

The adsorption capacity of acetylsalicylic acid was evaluated using carbon xerogel (CX) and carbon xerogel modified with TiO₂ nanoparticles (CXM). These materials were characterized by different techniques such as Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), and Fourier Transform Infrared (FTIR) spectroscopy. BET surface area measurements found values of 762 m² /g and 214 m² /g for CX and CXM, respectively. Batch experiments show that the Langmuir-Freundlich model best represents the experimental adsorption isotherm, in addition to show a maximum adsorption capacity of 17,48 mg/g. In continuous experiments, the effect of the inlet concentration and flow rate on the adsorption capacity of the micro-packed bed adsorber were evaluated. Breakthrough curves agree well with the axial dispersion model. In view of their adsorption capacity, carbon xerogels provide a potential material for the removal of emergent contaminants from the pharmaceutical industry. Besides, the incorporation of TiO₂ nanoparticles allows the implementation of complementary techniques, e.g. photodegradation, as an alternative to achieve higher elimination of aqueous contaminants.