Levofloxacin Degradation, Antimicrobial Activity Decrease, and Potential for Water Disinfection Using Peroxydisulfate Activation by Ag/TiO<sub>2</sub> under Sunlight
Sindy D. Jojoa-Sierra,
Cesar Jaramillo-Paez,
Efraím A. Serna-Galvis,
Inés García-Rubio,
María C. Hidalgo,
José A. Navío,
María P. Ormad,
Ricardo A. Torres-Palma,
Rosa Mosteo
Affiliations
Sindy D. Jojoa-Sierra
Grupo de Investigación Agua y Salud Ambiental, Instituto Universitario de Investigación en Ciencias Ambientales de Aragón (IUCA), Universidad de Zaragoza, 50018 Zaragoza, Spain
Cesar Jaramillo-Paez
Departamento de Química, Facultad de Ciencias, Universidad del Tolima, Ibagué 730006299, Colombia
Efraím A. Serna-Galvis
Grupo de Investigación en Remediación Ambiental y Biocatálisis (GIRAB), Instituto de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Medellín 050010, Colombia
Inés García-Rubio
Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain
María C. Hidalgo
Instituto de Ciencias de Materiales de Sevilla, Centro Mixto Universidad de Sevilla-CSIC, 41092 Sevilla, Spain
José A. Navío
Instituto de Ciencias de Materiales de Sevilla, Centro Mixto Universidad de Sevilla-CSIC, 41092 Sevilla, Spain
María P. Ormad
Grupo de Investigación Agua y Salud Ambiental, Instituto Universitario de Investigación en Ciencias Ambientales de Aragón (IUCA), Universidad de Zaragoza, 50018 Zaragoza, Spain
Ricardo A. Torres-Palma
Grupo de Investigación en Remediación Ambiental y Biocatálisis (GIRAB), Instituto de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Medellín 050010, Colombia
Rosa Mosteo
Grupo de Investigación Agua y Salud Ambiental, Instituto Universitario de Investigación en Ciencias Ambientales de Aragón (IUCA), Universidad de Zaragoza, 50018 Zaragoza, Spain
Water quality and usability are global concerns due to microbial and chemical pollution resulting from anthropogenic activities. Therefore, strategies for eliminating contaminants are required. In this context, the removal and decrease in antibiotic activity (AA) associated with levofloxacin (LEV), using TiO2 and Ag/TiO2 catalysts, with and without sunlight and peroxydisulfate, was evaluated. Additionally, the disinfection capacity of catalytic systems was assessed. The catalysts were synthesized and characterized. Moreover, the effect of Ag doping on visible light absorption was determined. Then, the photocatalytic treatment of LEV in water was performed. The materials characterization and EPR analyses revealed that LEV degradation and AA decrease were ascribed to a combined action of solar light, sulfate radical, and photocatalytic activity of the TiO2-based materials. Also, the primary byproducts were elucidated using theoretical analyses (predictions about moieties on LEV more susceptible to being attacked by the degrading species) and experimental techniques (LC-MS), which evidenced transformations on the piperazyl ring, carboxylic acid, and cyclic ether on LEV. Moreover, the AA decrease was linked to the antibiotic transformations. In addition, the combined system (i.e., light/catalyst/peroxydisulfate) was shown to be effective for E. coli inactivation, indicating the versatility of this system for decontamination and disinfection.