Removal of antibiotic compounds by adsorption using glycerol-based carbon materials

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 296; pp. 277 - 288
• Main Authors: Álvarez-Torrellas, S., Ribeiro, R.S., Gomes, H.T., Ovejero, G., García, J.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-07-2016
• Subjects: Adsorption; Antibiotics; Carbon; Carbon materials; Emerging contaminants; Fourier transforms; Isotherms; Reaction kinetics; Surface chemistry; Synthesis; Tetracyclines; Adsorption; Antibiotics; Carbon materials; Emerging contaminants
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2016.03.112

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•First work studying the removal of antibiotics by carbonaceous materials prepared from glycerol.•Kinetic and equilibrium adsorption tests onto glycerol-based carbon materials.•Textural and chemical adsorbents properties played a critical role in the adsorption performance.•Film mass transfer and pore diffusion coefficients were estimated.
This study is focused on the synthesis and application of glycerol-based carbon materials (GBCM200, GBCM300 and GBCM350) as adsorbents for the removal of the antibiotic compounds flumequine and tetracycline from aqueous solution. The synthesis enrolled the partial carbonization of a glycerol-sulfuric acid mixture, followed by thermal treatments under inert conditions and further thermal activation under oxidative atmosphere. The textural properties were investigated through N2 adsorption–desorption isotherms, and the presence of oxygenated groups was discussed based on zeta potential and Fourier transform infrared (FTIR) data. The kinetic data revealed that the equilibrium time for flumequine adsorption was achieved within 96h, while for tetracycline, it was reached after 120h. Several kinetic models, i.e., pseudo-first order, pseudo-second order, fractional power, Elovich and Weber–Morris models, were applied, finding that the pseudo-second order model was the most suitable for the fitting of the experimental kinetic data. The estimated surface diffusion coefficient values, Ds, of 3.88 and 5.06×10−14m2s−1, suggests that the pore diffusion is the rate limiting step of the adsorption process. Finally, as it is based on SSE values, Sips model well-fitted the experimental FLQ and TCN adsorption isotherm data, followed by Freundlich equation. The maximum adsorption capacities for flumequine and tetracycline was of 41.5 and 58.2mgg−1 by GBCM350 activated carbon.