Treatment Of Non-steroidal Anti-inflammatory And Analgesic Pollutants By Mn-based Cu/Fe Supported Particle Electrode

Non-steroidal anti-inflammatory analgesic pollutants belong to drugs and personal care products（PPCPs）pollutants,is a widely present in the environment of trace pollutants,with persistent,bioaccumulation,long-distance migration characteristics,The toxicity of these pollutants varies,there is a huge potential threat to biological health.Traditional sewage treatment process is difficult to remove it,the study of new treatment methods is imminent.Based on the existing electrocatalytic technology,the reactor was designed and fabricated to construct the three-dimensional particle electrode reaction system.The effects of electrocatalytic oxidation and quasi-electricity on the removal efficiency of nonsteroidal anti-inflammatory analgesic pollutants were studied.The optimal working conditions and the degradation path and mechanism of the target pollutants were discussed respectively.Based on the concept of waste utilization,the manganese residue was selected as the particle electrode carrier.According to the structure of the target pollutant,the transition metal Mn and Fe were selected as the catalytically active substances.After pretreatment with ultrasonic cleaning and drying,the particles were prepared by impregnation-roasting method.The particle electrode was screened by the removal rate of salicylic acid as the index,and it was found that under the same conditions Under the loading of Cu: Fe = 1: 1,the removal rate of salicylic acid was the highest.The surface area of the particles after loading by SEM,XRF and other means is increased,and the proportion of Cu and Fe in the component is greatly improved.Aiming at the problem of corrosion of the main electrode in the electrocatalytic reaction,PANI / Ti was prepared by using the microemulsion method to prepare the PANI / Ti electrode with the conductive polymer polyaniline as the carrier.Polyaniline modified electrode series characteristics.The results show that the modified PANI / Ti performance is better than that of the electrochemical workstation.The results show that the PANI / Ti performance is better than that of the electrochemical workstation,and the electrocatalytic activity of the electrode is improved.,Increasing the electrocatalytic reaction sites in the reactor.The particle electrode with Cu: Fe = 1: 1 was filled in a special reactor.PANI / Ti was used as anode and carbon fiber as cathode to construct three-dimensional particle electrode reactor.Based on the salicylic acid removal rate,the single factor test of tank voltage,electrolyte type and concentration,influent pH,plate spacing,hydraulic retention time and initial pollutant concentration were selected,and the key influencing factors were selected.Water pH,hydraulic retention time and initial pollutant concentration.Experiments show that there is no interaction between influent pH and initial pollutant concentration,and there is no interaction between the other two factors.The optimum conditions for the catalytic oxidation of the three-dimensional particle electrode were predicted by Design-Expert8.0.6 software: the tank voltage was 8V,the influent pH was 3 and the initial pollutant concentration was 0.05 mg / L.Under this condition,Anti-inflammatory analgesic contaminants salicylic acid,ketoprofen and diclofenac.The removal rate of salicylic acid was 76.85%,which was similar to the predicted value.The removal rates of ketoprofen and diclofenac were 39.21% and 32.48%,respectively,which were much lower than the predicted values.In order to improve the removal efficiency of ketoprofen and diclofenac,the persulfate and persulfate activators were introduced into the three-dimensional particle electrode reactor,and the activated persulfate was strengthened under the action of the electric field,and the reaction was similar to that of EA-Fenton.Based on the removal rate of diclofenac,the optimum persulfate dosage and the optimum type of persulfate activator(Fe²⁺,Fe⁰)were investigated.The results showed that the optimum dosage of sulphate was 1.5 Mmol / L,Fe0 is more suitable as the activator of persulfate,the best dosage is 3mmol / L.When the water retention time is 120 min,the influent pH is 3,the tank voltage is 8V,the initial pollutant concentration is 0.05 mg / L,the plate spacing is 4cm,the electrolyte concentration is 0.05 mol / L,the persulfate dosage is 1.5mmol / L,Fe⁰ dosage of 3mmol / L,the removal rate of salicylic acid and ketoprofen reached 95.73% and 84.85% respectively.In the reaction system,the addition of excess chemical nitrobenzene and ethanol,nitrobenzene capture,ethanol can be captured simultaneously and · OH.The experimental results show that both the presence of the reaction system and · OH,the removal of contaminants is two free radicals The result of the interaction.The solid phase extraction column was used for methanol activation by solid phase extraction.The water samples before and after the test were extracted and eluted with methanol.The eluent was collected and the eluate was treated with about 2 ml by nitrogen blowing.To the analysis of special vials for high performance liquid chromatography,it was found that salicylic acid,diclofenac acid degradation in different retention time have different intermediate product peak,and ketoprofen only detect ketoprofen content reduction,intermediate products peak It is not clear that the process of ketoprofen degradation is carried out quickly,with no intermediate product accumulated.The main changes in the degradation process of the target contaminants were as follows:（1）Salicylic acid as the ·OH scavenger,mainly under the action of ·OH,decarboxylation reaction and benzene ring And then in the occurrence of open-loop reaction was mineralized;（2）ketoprofen and ·OH in the role of decarboxylation reaction occurred,the benzene ring on the substitution reaction,carbonyl oxidation reaction,and then mineralized,the whole degradation The process is very fast,no intermediate product accumulation;（3）diclofenac and ·OH in the role of decarboxylation,dechlorination,benzene ring on the substitution reaction,and then open-loop reaction was mineralized.