Degradation Of Typical Antibiotics In Effluent Of Municipal Wastewater Treatment Plant By O3/UV

As an emerging contaminant,antibiotics have been of increasing concern over the last decade since various antibiotics have been frequently detected in the environment including surface water,groundwater and drinking water.Antibiotics could enter into the environmental waters through the effluents from wastewater treatment plants?WWTPs?which cannot eliminate the antibiotics completely.Therefore,WWTPs play an important role in the pollution source of antibiotics to the environment.In this paper,5 kinds of fluoroquinolones were selected as the target contaminants to investigate the treatment of antibiotics from effluent in WWTPs by using advanced oxidation technology.According to the pre-experiment,the removal efficiency of target contaminants by using advanced oxidation technology including O₃,UV and O₃/UV methods was investigated.And the results showed that O₃/UV had the highest removal efficiency of the target contaminants.The scope of O₃/UV parameters:the dosage of ozone was 3to 5 mg/L,the UV intensity was 1.67 to 4.16 W/L and the pH value was 7 to 10,respectively.The effect of ozone dosage,UV incident intensity,initial pH value of solution and reaction time on the degradation of fluoroquinolone antibiotics by O₃/UV was studied by response surface method.The results showed that 4 factors have significant influence on the response value.The removal rate of the target pollutants had the highest value when the ozone dosage was 5 mg/L,the UV radiation intensity was 4.16W/L,the initial pH value of the solution was 9.41 and the reaction time was 154 min.The further experimental results showed that fleroxacin,enoxacin,norfloxacin and lomefloxacin in secondary effluent could be degraded effectively by O₃/UV method.And the highest removal rate can reach 59.25%,82.35%,74.49%and 78.3%respectively when the reaction time was 150 min.The degradation process were in accordance with pseudo first-order kinetics,and the reaction rate constant was 0.0015to 0.0050 min^-1,0.0065 to 0.018 min^-1,0.0033 to 0.0139 min^-1,0.0045 to 0.0087 min^-1respectively.The products of 5 fluoroquinolones degraded by O₃/UV were analyzed,and the degradation pathways of fluoroquinolone antibiotics by O₃/UV were deduced according to the detected products.