Abstract:
Antibiotics are emerging organic contaminants that enter wastewater network as consequence of human activities, and transferred to sewage sludge by sorption during wastewater treatment. The treatment of antibiotics in waste activated sludge (WAS) deserves special attention since antibiotics have potential to cause the spreading of antibiotic resistant bacterial pathogens in contrast to other emerging organic contaminants. Although Fenton oxidation has been considered as a promising pre-treatment method by providing sludge disintegration and degradation of recalcitrant compounds, there is a lack for the determination of antibiotics’ fate during Fenton oxidation of WAS. The efficiencies of Fenton and Fenton-like oxidation for oxytetracycline (OTC) antibiotic, which exhibits high sorption capacity, were evaluated in synthetically contaminated WAS at different experimental conditions. While increased H2O2 dosage and [Fe+2]/[H2O2] ratio affected process efficiency positively, higher total solid content of WAS drastically reduced the OTC degradation. Fenton and Fenton-like oxidations provided 94 % and 87% OTC degradation with 150 g/kg TS H2O2 and 1.2 Fe/H2O2 molar ratio in 120 minutes treatment time, respectively. Metal and nutrient release and enhanced physical properties were additional results of the Fenton oxidation.
