AVENA marcelo Javier
Synthesis and characterization of mesoporous silica powders and application to antibiotic remotion from aqueous solution. Effect of supported Fe-oxide on the SiO2 adsorption properties
MAXIMILIANO BRIGANTE; M. EUGENIA PAROLO; PABLO SCHULZ; MARCELO AVENA
ELSEVIER SCIENCE SA
Lugar: Amsterdam; Año: 2014 vol. 253 p. 178 - 186
The remotion of the antibiotic minocycline (MC) on mesoporous silica (SiO 2 ) and on the binary system iron(III) oxide?SiO 2 (Fe-SiO 2 ) has been studied in batch experiments by performing adsorption isotherms/kinetics under different conditions of pH, KCl concentration and temperature. The adsorption of MC on the studied materials is strongly dependent on pH, increasing as pH decreases. The incorporation of a low concentration of iron (1.03 wt.%, mainly as amorphous Fe 2 O 3 ) on the SiO 2 matrix not only increases the adsorption capacity but also changes the adsorption mechanism. The adsorption of MC on SiO 2 strongly decreases as KCl concentration increases but it is not signiﬁcantly affected by varying the temperature. This is attributed to electrostatic attrac- tions and H-bond formations between dimethylamino, amide, carbonylic and phenolic groups of the antibiotic and the functional groups of silica particles. The adsorption of MC on Fe-SiO 2 , on the contrary, strongly increases as temperature increases but remains invariable by varying the KCl concentration. This suggests that the forma- tion of inner-sphere complexes between the functional groups of the antibiotic and the active sites of Fe 2 O 3 plays a key role on the adsorption mechanism. The analysis of adsorption thermodynamic parameters is also reported and discussed. The synthesized materials can act as excellent adsorbents for environmental and engineering processes.