Degradation of tetracyclines in different water matrices by advanced oxidation/reduction processes based on gamma radiation
Article first published online: 24 OCT 2012
© 2012 Society of Chemical Industry
Journal of Chemical Technology and Biotechnology
Volume 88, Issue 6, pages 1096–1108, June 2013
How to Cite
López Peñalver, J. J., Gómez Pacheco, C. V., Sánchez Polo, M. and Rivera Utrilla, J. (2013), Degradation of tetracyclines in different water matrices by advanced oxidation/reduction processes based on gamma radiation. J. Chem. Technol. Biotechnol., 88: 1096–1108. doi: 10.1002/jctb.3946
- Issue published online: 14 MAY 2013
- Article first published online: 24 OCT 2012
- Manuscript Revised: 4 SEP 2012
- Manuscript Accepted: 4 SEP 2012
- Manuscript Received: 18 MAY 2012
- advanced oxidation/reduction process (AORP);
This study analyzes the efficacy of a gamma radiation advanced oxidation/reduction process (AORP) to treat waters contaminated with the antibiotics tetracycline (TC), chlortetracycline (CTC), and oxytetracycline (OTC).
Study results indicate that: (1) radiolysis of the three TCs fits a pseudo-first-order kinetic model in which the radiation-chemical yield decreases with higher absorbed dose; (2) the value of the dose constant depended on the dose rate, which ranged from 3.83 to 1.66 Gy min–1, and depended to a small extent on the medium pH between pH values of 2.0 and 10.0, since aqueous electrons and hydroxyl radicals both act in TC degradation; (3) the effectiveness of the process was slightly increased at low concentrations of H2O2; (4) the presence of Cl−, , , and humic acid influenced TCs degradation, which was higher at low concentrations of Cl−, and HA and markedly decreased at low concentrations of of and ; (5) the dose constant is lower in natural waters; (6) TOC values for ultrapure water, surface water, groundwater and wastewater showed that it is not possible to obtain complete TC mineralization at the absorbed doses; (7) the toxicity of byproducts formed during the radiolytic process was lower.
Gamma radiation, an oxidation/reduction procedure, is an effective treatment for removing TC, CTC and OTC from aqueous solutions. TC degradation takes place by both oxidation and reduction pathways, with a predominance of the latter, as demonstrated by the markedly reduced dose constant in the presence of aqueous electron scavengers.