Oxolinic Acid Binding at Goethite and Akaganéite Surfaces: Experimental Study and Modeling
2016 (English)In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 50, no 2, 660-668 p.Article in journal (Refereed) Published
Oxolinic acid (OA) is a widely used quinolone antibiotic in aquaculture. In this study, its interactions with synthetic goethite (α-FeOOH) and akaganeite (β-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-Fouriertransform infrared (ATR-FTIR) spectroscopy and multisitecomplexation (MUSIC) modeling were used to monitor OAbinding 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 atcircumneutral to low pHc =−log [H+] and with a strongly hydrogen-bonded complex at high pHc. The stronger OAbinding to akaganeite 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+)atthis 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 inmarine sediments and waters.
Place, publisher, year, edition, pages
American Chemical Society (ACS), 2016. Vol. 50, no 2, 660-668 p.
IdentifiersURN: urn:nbn:se:umu:diva-124988DOI: 10.1021/acs.est.5b04940OAI: oai:DiVA.org:umu-124988DiVA: diva2:957218