Activation Of Peroxymonosulfate By Continuous Flow Reactor Packed With Supported Cobalt Ferrite For The Degradation Of Organic Contaminants In Water

The treatment of organic wastewater has become an urgent problem in water pollution,and dye wastewater has become a difficult problem in organic wastewater treatment due to its characteristics of difficult degradation,high chromaticity,complex composition,and large emissions.Sulfate radicals(SO₄^·-)have the characteristics of strong oxidation,long half-life,and wider working p H range.The advanced oxidation technology dominated by SO₄^·-has become a research hotspot in water treatment.In the existing research,Co Fe₂O₄ catalyst is recognized as having good activated PMS effect and less cobalt leaching,which has certain practicality in treatment of organic wastewater by activating PMS.In order to avoid the complex solid-liquid separation process of adding nanoscale powder catalysts by traditional batch catalytic methods,the nanocatalytic materials were supported on a suitable carrier,and the composite catalytic materials were filled in the reaction column to build a continuous flow phase catalytic reactor to treat dye wastewater OrangeⅠ（OI）in this experiment.The main research work is as follows:The complex pore structure of the natural mineral carrier and the presence of metallic elements in it favor the supporting and catalysis.Co Fe₂O₄-volcanic stone composite catalytic materials were prepared by co-precipitation-impregnation method,and the effects of calcination temperature,calcination duration and metal salt dosage on catalytic performance were studied.Co Fe₂O₄-volcanic stone/PMS catalytic reactor was built to continuously treat large-scale simulated dye wastewater Orange I（OI）,in which the OI concentration,PMS dosage,influent flow rate,initial p H,and the presence of anions and humic acids in the water had effects on the treatment efficiency of the reactor.The reaction column was filled with 50 g of composite catalyst material with an initial contaminant concentration of 10 mg/L,PMS dosage of 150μmol/L,flow rate of 18.4 m L/min,the removal efficiency of the reactor operating within 240 min can be more than 92%.SO₄^·-and ¹O₂,as the main reactive oxygen species in the system,dominate the oxidative degradation of OI through radical and non-radical pathways.the formation of surface hydroxyl groups has an important impact on the catalytic process.There is a synergistic effect between the bimetals on the surface of the support.The strong adsorption effect of activated carbon carrier and the electron rich structure of carbon material can synergistically activated PMS and removed OI,and reduce the ion dissolution of the system to improve the stability of the composite catalyst.Co Fe₂O₄-activated carbon composite catalyst materials were prepared by urea-assisted combustion,and the preparation method was optimized from the perspective of material stability and catalytic performance.The reaction column was filled with 30g of composite catalyst material with an initial pollutant concentration of 10 mg/L,PMS dosage of 150μmol/L,flow rate of 73.6 m L/min,the removal efficiency of the reactor operation within 240 min can be more than 82%,and the mineralization rate is 47%.Compared with the Co Fe₂O₄-volcanic stone/PMS catalytic system,the Co Fe₂O₄-activated carbon/PMS catalytic system can achieve stable treatment of large quantities of dye wastewater under high flow rate conditions.The response surface optimization design was used to optimize the operating conditions of Co Fe₂O₄-activated carbon/PMS reactor.The model fit yielded the optimal operating conditions:when the OI concentration was 17.8 mg/L,the PMS concentration was 200μmol/L,and the influent flow rate was 349rpm（107.0 m L/min）,the OI removal rate could reach 95.07%.The catalytic reactor was used to treat a variety of target pollutant aqueous solutions（including methylene blue,bisphenol A and tetracycline）,all of which achieved good removal effect.