Study On The Advanced Treatment Process Of Norfloxacin Production Wastewater By Magnetic Coagulation-ozone Oxidation

In view of the increasingly stringent river basin or regional emission standards in various provinces and cities,the biochemical effluent from wastewater treatment station of a norfloxacin pharmaceutical enterprise in Zhengzhou city was taken as the research object in test,by comparing the combined advanced treatment efficiency of magnetic coagulation process and different ozone oxidation processes under optimized parameters,an efficient magnetic coagulation-ozone oxidation optimized combined process was proposed to provide parameter support for the company’s subsequent advanced treatment process transformation.The parameters of magnetic coagulation process were optimized by single factor test and response surface methodology.The optimal parameters of magnetic coagulation process were determined as follows:the optimal coagulant was polyferric sulfate（PFS）with dosage of 403 mg/L,the optimal coagulant aid was cationic polyacrylamide（CPAM）with dosage of 7.24 mg/L,the particle size of magnetic powder was 300 mesh with dosage of 316 mg/L,the addition sequence of chemical was magnetic powder+PFS-CPAM;the rapid stirring speed was 300 rpm and time was 3 min,the slow stirring speed was 30 rpm and time was 15 min under hydraulic conditions;the water quality conditions were that the initial p H value was 7 and the initial temperature was 25℃.Based on effluent under the optimized parameter conditions of the magnetic coagulation process except for water quality conditions,the optimal parameter conditions of ozone,UV/O₃and activated char catalyzed ozonation process in ozone oxidation process were determined as follows:the dosage of ozone was 26 mg/min,the initial p H value was 9,and the initial temperature was 20℃,and the oxidation time was 60 min.In addition,the filling rate of column in activated char catalyzed ozonation was optimized to 40%.The comparison of different ozone oxidation processes showed that activated char catalyzed ozonation process had the best treatment effect and the highest overall reaction rate constant among the three processes,and the reaction process conforms to the first order reaction kinetics.Considering comprehensively,activated char catalyzed ozonation was determined to be the best combined process with magnetic coagulation.Comprehensive magnetic coagulation-activated char catalyzed ozonation process treatment efficiency,and based on operation condition of wastewater treatment station of the norfloxacin pharmaceutical enterprise,the chroma and COD indicators of effluent from magnetic coagulation-activated char catalyzed ozonation process can meet the special emission limits specified in the discharge standard of water pollutants for Jialu River basin（DB 41/908—2014）.