Role of [FeOx(OH)y] surface sites on the adsorption of β-lactamic antibiotics on Al2O3 supported Fe oxide.
In this work, [FeOx(OH)y]/Al2O3 composites with different Fe oxyhydroxy contents, i.e. 10, 20 and 50wt% treated at 150, 200, 300 and 450°C were investigated as adsorbents of β-lactamic antibiotics, i.e. cephalexin, ceftriaxone and especially amoxicillin, from aqueous solutions. The obtained results showed that the nature of the surface Fe(3+) species play a fundamental role on the adsorption process. The most efficient adsorption was obtained for the sample 150Fe50A (50% [FeOx(OH)y] supported in Al2O3 treated at 150°C) whereas the thermal treatment at higher temperatures caused a strong decrease on the adsorption capacity. Mössbauer, XRD, FTIR, Raman, TG-MS, SEM, CHN and BET of the composite 150Fe50A suggested an approximate composition of FeO0.65(OH)1.7 whereas at 450°C strong dehydroxylation process takes place to form FeO1.4(OH)0.21. These results combined with competitive adsorption using amoxicillin mixed with phosphate or H2O2 suggest that the antibiotic molecules adsorb by complexation on surface sites likely based on FeOx(OH)y by the replacement of the labile OH ligands.
Departamento de Química, Universidade Federal de Minas Gerais, UFMG, Belo Horizonte, MG 31270-901, Brazil.
Paula S
PS
Pinto
Departamento de Química, Universidade Federal de Minas Gerais, UFMG, Belo Horizonte, MG 31270-901, Brazil.
Tayline P V
TPV
Medeiros
Laboratório de Física Aplicada, Centro de Desenvolvimento da Tecnologia Nuclear, CDTN/CNEN, Belo Horizonte, MG 31270-901, Brazil.
José D
JD
Ardisson
Departamento de Química, Universidade Federal de Minas Gerais, UFMG, Belo Horizonte, MG 31270-901, Brazil. Electronic address: rochel@ufmg.br.
Rochel M
RM
Lago
D000327:Adsorption; D000537:Aluminum Oxide / Q000737:chemistry*; D000900:Anti-Bacterial Agents / Q000032:analysis*; D005290:Ferric Compounds / Q000737:chemistry*; D013499:Surface Properties; D062065:Wastewater / Q000737:chemistry*; D018508:Water Purification; D047090:beta-Lactams / Q000032:analysis*
D000537:Aluminum Oxide; D000900:Anti-Bacterial Agents; D005290:Ferric Compounds; D062065:Wastewater; D047090:beta-Lactams; C000499:ferric oxide
Adsorption; Amoxicillin; Beta-lactam; Complexation; Iron oxyhydroxy