Recycling

Biography

Biography: Pelin Alicanoglu

Abstract

Antibiotics are extensively being used in our lives for human disease treatment, aquaculture, and livestock operations. Due to the inappropriate wastewater disposal practices, a portion of the antibiotics are discharged into the environment in their original or metabolized forms [1]. Levofloxacin (LEV) is a more recently developed antibiotic belonging to the fluoroquinolones (FQs) which are synthetic broad spectrum antibiotics and is the optical S-(-) isomer of ofloxacin [2]. However, it is difficult to remove LEV from wastewater through traditional biological methods because of its toxicity and low biodegradability [2]. Graphene oxide (GO) is hydrophilic due to the oxygen-containing functional groups on its surface, which renders GO sheet a good candidate for supporting nanoparticles in liquid phase [3]. TiO2 could produce powerful oxidants capable to degrade organic pollutants until total mineralization [4]. Semiconductor materials have been widely studied and used in the fields of pollutant degradation due to their environment friendliness [3]. The aim of the present work was to synthesize a new nanoparticle (G-TiO2) and remove LEV antibiotic from synthetic wastewater at different operational conditions. In order to determine the maximum photodegradation yields of LEV with G-TiO2 composite, the effects of increasing LEV concentrations (1, 5, 25 and 100 mg/L), increasing irradiation times (15, 30, 45, 60 and 120 min), increasing G-TiO2 concentrations (0.1, 0.25, 0.5, 1 and 2 g/L) and different pH levels (4, 7 and 10) were researched. The maximum removal efficiency of LEV (for 1 mg/L) was obtained as 97% {G-TiO2 concentration: 0.25 g/L, pH: 7, temperature: 21°C, UV power: 300 W, irradiation time: 45 min}. Moreover, six sequential treatment steps were investigated for determination of reusability of G-TiO2 composite. The photocatalytic degradation percentage was reduced from 97% to 74% on first cycle to sixth cycle.