Removal of the antibiotic levofloxacin (LEVO) in water by ozonation and TiO2 photocatalysis

Removal of the fluoroquinolone antibiotic levofioxacin (LEVO) was studied in two oxidation processes: photocatalysis (UVC lamp (254 nm), TiO2) and ozonation. LEVO (C-o = 20 mg/L) was no longer detected after an ozone dose of 20.5 mg/L and after 180 min of photocatalytic oxidation. COD removals of 59% and 70% were measured for 270 mg/L of transferred ozone dose and 300 min of photocatalytic oxidation, respectively. Extensive treatment with ozone did not result in further reduction in COD levels reaching a plateau at the above mentioned value, however increased irradiation time led to increased COD removal during photocatalytic treatment. Both treatment methods proved to be effective ways of removing antibacterial activity. From agar diffusion test with Escherichia coli, it was observed that a transferred ozone dose of at least 20.5 mg/L and 180 min of irradiation were enough to completely remove antibacterial activity. Both treatments methods were shown to efficiently remove LEVO and its antibacterial activity and show promising results as possible applications for removal of antibiotics in wastewater. (C) 2012 Elsevier B.V. All rights reserved.