The Study Of The Distribution Of Antibiotics In Water Of A River And The Degradation Of Ofloxacin

As more and more attention is paid to environmental protection,water pollution control has been continuously listed in the 12th Five-year Plan and the 13th Five-year Plan.The increasingly serious problem of water contamination has caused a certain threat to drinking water sources in our country,and the refractory micropollutant is a new type of pollutants gathered in the water.Antibiotics,as a kind of typical Refractory micropollutants,have the characteristics of low concentration,high toxicity and are easy to accumulate.Due to long-term continuous emissions finally antibiotics form "Pseudo persistent pollutants",which can severely damage the stability and diversity of ecosystems,and at the same time enter human body along the food chain,then destroy the body’s immune system and cause various diseases.This paper studied the water quality index,the antibiotic contamination and the antibiotic distribution characteristics in the surface water of a spare water source,which is the main stream of a river basin in South China,then made the degradation test of quinolone antibiotics ofloxacin by Ultrasonic Catalytic Oxidation Technology and Photocatalytic Oxidation Technology,and studied the effects of different factors on the degradation effect of ofloxacin,discussesed the degradation kinetics and degradation mechanism.The main conclusions of this study are:1.Through the study of the water quality index,antibiotic contamination and the distribution characteristics of the surface water of the main stream of a river basin in South China,the results showed that the overall water quality accorded with the surface water quality standard of class Ⅱ and Ⅲ,and the water quality is good.At the same time,a large number of antibiotics were detected in water(17 kinds of antibiotics),including sulfa antibiotics,macrolide antibiotics and fluoroquinolone antibiotics,the species and distribution of antibiotics in water would be affected by seasonal changes and human activities.2.By comparing the Ultrasonic Catalytic Oxidation,Ultraviolet Catalytic Oxidation of degradation characteristics of ofloxacin containing water,the effects of ultrasonic power,initial pH value of solution,dosage of oxidant and initial concentration of solution on the degradation of ofloxacin were discussed.Under the condition of different ultrasonic power,initial pH value of the solution,the dosage of oxidant and initial concentration of the solution,the degradation effect of UV catalytic oxidation technology of ofloxacin was better than ultrasonic catalytic oxidation technology.3.By using Ultraviolet Catalytic Oxidation on the degradation of ofloxacin,the effects of dosage of oxidant,initial pH value and initial concentration of solution on the degradation of ofloxacin by UV/H2O2 or UV/K2S2O8 were discussed.The results showed that the free radicals produced by photolysis and photolysis of UV light both played an important role in the ultraviolet catalytic oxidation degradation of ofloxacin.Under the condition of different the dosage of oxidant,and initial pH value and concentration of the solution and,the degradation process of ofloxacin useing Ultraviolet Catalytic Oxidation all could be described by the first-order reaction rate model.4.Response surface methodology was studied to analyse the factors affecting the ofloxacin degradation in the water by Ultraviolet Catalytic Oxidation.The dosage of oxidant(H2O2,K2S2O8),the pH value and concentration of the initial solution and were taken as independent variables,respectively,and the degradation efficiency and degradation rate of ofloxacin were the response values.By the central composite design module,a presictive polynomial quadratic model was set up and can be used to simulate the process for degradation of ofloxacin by UV/K2S2O8,UV/H2O2.