Reclamation of hospital secondary treatment effluent by sulfate radicals based-advanced oxidation processes (SR-AOPs) for removal of antibiotics

摘要

Nowadays, pollution of water resources by emerging resistant contaminants such as antibiotics is a growing issue. The limitations in conventional treatment methods for the removal of emerging contaminants intrigued the researcher to propose advanced treatment methods. Moreover, the high values of carbon-based compounds in wastewater and also treated effluent arise issues in treatment processes. Thus, this study aims to determine the removal of amoxicillin and ciprofloxacin from hospital effluent using an ultraviolet-activated persulfate-based advanced oxidation process. The effect of the study variables including persulfate concentration (2.5-10 mg L-1), pH(4-11), initial concentration of antibiotics (1,10 mg L-1) and reaction time (2.5-120 min) was investigated on the removal of antibiotics. Moreover, the chemical reaction kinetics and mineralization rate were determined and the interference effect of various ions was investigated. The results showed that the highest removal of ciprofloxacin and amoxicillin were observed to be respectively 99.9% and 99.26% at the reaction time of 60 min, initial concentration of 1 mg L-1 and persulfate concentration of 10 mg L-1. The antibiotics removal rate increased as their initial concentration decreased Further, increase of the persulfate concentration and reaction time increased the removal rate. Degradation kinetics of ciprofloxacin and amoxicillin followed the pseudo-first-order equation. The use of persulfate did not significantly increase the sulfate and nitrate content of wastewater. Moreover, mineralization was not performed in the ultraviolet/persulfate process for both antibiotics. The results showed that the ultraviolet-activated persulfate-based advanced oxidation process can be used as an appropriate method for the removal of antibiotics in complicated aqueous media such as hospital effluent.