Free Radicals Of Ferrite Spinel Study On Oxidation System In Degradation Of Quinoline

Quinoline in the pharmaceutical,printing and dyeing,chemical and other industries ubiquitous,is a very important fine chemical raw materials.However,if released into the environment,the animals and plants will cause serious toxic effects.In the coal gasification wastewater,quinoline compounds concentration of up to 40 mg/L or more,is the second largest pollutant after the phenol.Is the second largest pollutant after the phenol.Because of its toxic and harmful,bio-inhibitory,traditional biochemical treatment can not be effective in the degradation of quinoline in wastewater,therefore,the use of advanced oxidation method to deal with the development trend of such waste water.In the advanced oxidation method,the sulfate radical oxidation system gradually stands out because of its strong oxidizing ability,fast oxidation rate,wide pH range and low selectivity.At present,the research on sulfate radicals is mainly focused on the preparation of high efficiency catalyst,the recovery of catalyst and the improvement of recycling rate,the disclosure of catalytic mechanism and so on.In this context,this study suggests the use of heterogeneous sulfate free radicals to degrade quinoline.The research contents include:preparation,characterization and catalytic activity evaluation of magnetic spinel catalyst;improving catalyst stability and reusability;research on catalytic mechanism;research on the efficiency of quinoline degradation.The results show that the catalytic effect of manganese ferrite is the best among the four catalysts of MFe2O4(M=Co,Mn,Cu,Zn)prepared by sol-gel method.At the calcination temperature of 350?,the formation of ferric manganese oxide crystal integrity,smaller particle size,showing a good catalytic effect and stability.In the sulfate free radical oxidation system of ferric ferrite spinel,the optimum reaction conditions for the degradation of methyl orange were as follows:the dosage of catalyst was 1g/L,the dosage of K2S2O8 was1g/L,The degradation rate reached 87.53%at 90 min.The repeatability of the catalyst is excellent,and the degradation rate of methyl orange is still above 80%after 8 times of repeated use.In addition,the catalyst dissolution rate and catalytic effect of a certain degree of correlation.The qualitative analysis of the generated free radicals by competitive kinetics showed that SO4·-plays a leading role in the sulfate free radical oxidation system of ferrite spinel,followed by OH.The degradation process of methyl orange was analyzed by UV-visible full-wavelength scanning.It was found that the large conjugate-N=N-in the methyl orange was broken during the reaction and the solution was decolorized and the benzene ring Also by SOa·-attack,resulting in small molecule compounds.In the experiment of degradation of quinoline,the optimum reaction parameters were pH=7,the dosage of K2S2O8 was 5g/L,the dosage of catalyst was lg/L,room temperature.At this time,the COD removal rate of quinoline reached 83.56%under the condition of reaction time of 60 min.The development of this project provides theoretical support for deep understanding of the preparation and activation mechanism of persulfate activator.It provides data support for further elucidating the mechanism of degradation of quinoline wastewater and the catalytic reaction kinetics,and is effective in the treatment of high efficiency and low cost.Quinoline wastewater provides a new way,therefore,has important theoretical value and practical significance.