Oxolinic Acid Binding at Goethite and Akaganéite Surfaces: Experimental Study and Modeling.
Environ Sci Technol
; 50(2): 660-8, 2016 Jan 19.
Article
em En
| MEDLINE
| ID: mdl-26678217
ABSTRACT
Oxolinic acid (OA) is a widely used quinolone antibiotic in aquaculture. In this study, its interactions with synthetic goethite (α-FeOOH) and akaganéite (ß-FeOOH) particle surfaces were monitored to understand the potential fate of OA in marine sediments where these phases occur. Batch sorption experiments, liquid chromatography (LC) analyses of supernatants, attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy and multisite complexation (MUSIC) modeling were used to monitor OA binding at these particle surfaces. Both LC and ATR-FTIR showed that adsorption did not degrade OA, and that OA adsorption was largely unaffected by NaCl concentrations (10-1000 mM). This was explained further by ATR-FTIR suggesting the formation of metal-bonded complexes at circumneutral to low pHc = -log [H(+)] and with a strongly hydrogen-bonded complex at high pHc. The stronger OA binding to akaganéite can be explained both by the higher isoelectric point/point-of-zero charge (9.6-10) of this mineral than of goethite (9.1-9.4), and an additional OA surface complexation mechanism at the (010) plane. Geminal sites (≡Fe(OH2)2(+)) at this plane could be especially reactive for metal-bonded complexes, as they facilitate a mononuclear six-membered chelate complex via the displacement of two hydroxo/aquo groups at the equatorial plane of a single Fe octahedron. Collectively, these findings revealed that Fe-oxyhydroxides may strongly contribute to the fate and transport of OA-type antibacterial agents in marine sediments and waters.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Poluentes Químicos da Água
/
Compostos Férricos
/
Ácido Oxolínico
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Compostos de Ferro
/
Sedimentos Geológicos
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Minerais
/
Antibacterianos
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Environ Sci Technol
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
França