Preparation Of Ho Doped Ti/SnO₂-Sb Electrode And Study On Its Degradation Of Fluoroquinolone Antibiotic Wastewater

With the development of economy and the progress of science and technology,more and more kinds of antibiotics have been discovered or synthesized by scientists,among which thousands of antibiotics have been widely used.Although the development and use of antibiotics have greatly improved the health level of humans and animals,the overuse and misuse of antibiotics have increasingly aroused public concern.Some residual agents and antibiotics that cannot be metabolized and absorbed by the human body and animals will enter the sewage treatment plant with domestic sewage,industrial waste liquid and medical waste water.However,conventional biological treatment methods are no t easy to degrade antibiotics,so that they can be discharged into surface water or even migrate to deep groundwater,which leads to the widespread existence and high detection level of antibiotics in the environment,and seriously threatens and endangers the health of plants,animals and human beings.Fluoroquinolones(FQs)antibiotics are one of the typical antibiotics,which are widely used in aquaculture,animal husbandry and the treatment of human diseases.With the increase of the use of FQs antibiotics,a large number of wastewater containing antibiotics are frequently produced and released into the environment,as a result,its pollution to the water environment is increasingly aggravated.Therefore,it is of great theoretical and practical significance to explore an efficient and convenient FQs antibiotic wastewater treatment technology.In this study,rare earth holmium doped modified Ti/SnO2-Sb electrode was prepared by Pechini method,and the optimal preparation parameters of the modified electrode were explored.The surface morphology,crystal phase structure and oxygen evolution potential of the electrode were characterized and measured by scanning electron microscopy(SEM),X-ray energy dispersive spectroscopy(EDS),X-ray diffraction(XRD),cyclic voltammetry(CV)and linear scanning voltammetry(LSV).At the same time,the prepared Ti/SnO2-Sb-Ho electrode was used as the anode for the electrochemical degradation of ofloxacin(OFX)antibiotic simulated wastewater and to explore the optimum parameters,possible mechanism and path of the degradation process.Which can enrich the theoretical knowledge of electrochemistry treatment of wastewater and provide corresponding theoretical support and technical guidance for the actual degradation of FQs antibiotic in water.The experimental results show that the optimal preparation parameters of the Ti/SnO2-Sb-Ho electrode are as follows:the electrode coating is brushed 8 times,the roasting temperature is 700 ℃,and the optimal doping ratio of Sn,Sb and Ho in the coating solution is 100:10:1.The optimal process parameters of OFX antibiotic simulated wastewater by using Ti/SnO2-Sb-Ho electrode as anode are as follows:the initial pH of the solution is the natural pH of the OFX simulated wastewater,the current density is 30 mA/cm2,the concentration of Na2SO4 in electrolyte solution is 0.3 mol/L,and the initial concentration of OFX is 50 mg/L.In addition,the degradation of OFX will be adversely affected when the wastewater contains organic matter.The degradation rate of OFX with initial concentration of 50 mg/L reached 99.32%after 90 min of electrochemical degradation under the optimum technological parameters.By analyzing the free radical scavenger experiment and the change of pH value in the degradation process of OFX,it can be seen that the degradation of OFX by the modified electrode mainly depends on the oxidation of ·OH(strong oxidizable substance)generated in the electrochemical oxidation process.Analysis of intermediates in OFX degradation by mass spectrometry showed that OFX was degraded by hydroxylation of quinolone rings,dealkylation,decarboxylation and cracking of piperazine ring.