TY - JOUR
T1 - Surface complexation of oxytetracycline by magnetite
T2 - Effect of solution properties
AU - Rakshit, Sudipta
AU - Sarkar, Dibyendu
AU - Elzinga, Evert J.
AU - Punamiya, Pravin
AU - Datta, Rupali
PY - 2014/2
Y1 - 2014/2
N2 - Adsorption behavior of oxytetracycline, a common veterinary antibiotic, on magnetite was studied as a function of solution chemistry. Macroscopic experiments coupled with sur face complexation modeling indicated evidence of strong inner-sphere type interaction of oxytetracycline with magnetite. Few studies have reported on the sorptive interactions of oxytetracycline (OTC), a veterinary antibiotic frequently detected in wastewater, surface water, and soils, with common Fe oxide minerals. The primary objective of this study was to investigate the sorption behavior of OTC on magnetite (Fe3O4) as a function of different solution properties such as pH, ionic strength, and initial OTC concentration. Results indicated that sorption of OTC by magnetite was rapid and complete within 24 h. The effect of ionic strength on sorption was negligible at low OTC surface coverage. The sorption envelope indicated that with increasing pH, OTC sorption on Fe3O4 decreased. Surface complexation modeling of magnetite-OTC interactions suggested the interactions of divalent anionic species of OTC with the magnetite surface. Four possible surface complexation reactions were postulated to explain the pH dependence of OTC sorption, indicating a rather complex potential sorption mechanism. Our results suggest that magnetite has the capability of immobilizing OTC in the environment, which may be of use to scientists in predicting the fate of OTC in Fe-oxide-rich soil.
AB - Adsorption behavior of oxytetracycline, a common veterinary antibiotic, on magnetite was studied as a function of solution chemistry. Macroscopic experiments coupled with sur face complexation modeling indicated evidence of strong inner-sphere type interaction of oxytetracycline with magnetite. Few studies have reported on the sorptive interactions of oxytetracycline (OTC), a veterinary antibiotic frequently detected in wastewater, surface water, and soils, with common Fe oxide minerals. The primary objective of this study was to investigate the sorption behavior of OTC on magnetite (Fe3O4) as a function of different solution properties such as pH, ionic strength, and initial OTC concentration. Results indicated that sorption of OTC by magnetite was rapid and complete within 24 h. The effect of ionic strength on sorption was negligible at low OTC surface coverage. The sorption envelope indicated that with increasing pH, OTC sorption on Fe3O4 decreased. Surface complexation modeling of magnetite-OTC interactions suggested the interactions of divalent anionic species of OTC with the magnetite surface. Four possible surface complexation reactions were postulated to explain the pH dependence of OTC sorption, indicating a rather complex potential sorption mechanism. Our results suggest that magnetite has the capability of immobilizing OTC in the environment, which may be of use to scientists in predicting the fate of OTC in Fe-oxide-rich soil.
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U2 - 10.2136/vzj2013.08.0147
DO - 10.2136/vzj2013.08.0147
M3 - Article
AN - SCOPUS:84893442391
VL - 13
JO - Vadose Zone Journal
JF - Vadose Zone Journal
IS - 2
ER -