Microwave-assisted Preparation Of Fe-PAN And Cu-Fe-PAN Chelate Fiber And Its Photo-fenton Catalytic Degradation Of PNP

As an important material of chemical industry,phenolic compounds are widely used in the fields of industrial manufacture,which are released into the environment in large quantities during production and usage.P-nitrophenol(PNP)is the most important mononitrophenol compounds in terms of its usage and potential harmfulness.PNP can be widely distributed in the environment for a long time and cause serious pollution.Therefore,it is one of the research hotspots at home and abroad to treat the PNP wastewater pollution.In this study,Fe(?)modified PAN chelate fiber(Fe-PAN)and Cu(?)-Fe(?)bimetal modified PAN chelate fiber(Cu-Fe-PAN)complexes were prepared by modifying PAN fiber under microwave irradiation,which were used as heterogeneous photo-Fenton catalyst for the oxidative degradation of PNP under visible-light irradiation.Microwave-assisted synthesis method is adopted to prepare photocatalytic Fe-PAN and Cu-Fe-PAN materials,and the reaction time and temperature were optimized.Then the modified PAN fibers were characterized using scanning electron microscopy/energy dispersive spectrometer(SEM/EDS),Fourier transform infrared spectroscopy(FT-IR),ultraviolet-visible diffusereflectancespectrum(UV-Vis DRS)and thermal gravimetric analysis(TG/DTG).The photocatalytic activities of the two catalysts were tested with PNP as the target pollutant.The influence factors in terms of degradation rate of PNP including pH value,the amount of catalyst and H2O2,initial concentration of PNP were investigated,respectively.The stabilities of the catalysts were tested and the deradation mechanism was discussed.The Fe-PAN catalyst was synthetized by microwave-assisted method,and its photocatalytic activity was studied.The effects of reaction time and temperature on the catalytic activity of Fe-PAN were investigated.The experimental results showed that when the heating time was 60 min at 50?,the photocatalytic performance of the prepared catalyst was the best.The removal rate after 180 min could reach 90%.The optimum conditions for the process of Fe-PAN photocatalyst were pH of 5,H2O2 concentration of 3.0 mmol/L,the catalyst dosage of 1 g/L and the initial PNP concentration of 10 mg/L.After the Fe-PAN cataly st was regenerated and used for 5 times,the removal rate of PNP could still reach 80%.and only a small amount of Fe3+ was dissolved,which indicated that Fe-PAN catalyst maintained a good stability,and reutilization performance.The optimum conditions for preparing Cu-Fe-PAN by microwave-assisted method were microwave temperature of 50? for 60 min.and the Cu/Fe molar ratio of 1:1.The experimental results showed that when pH was 5,H2O2 concentration was 3 mmol/L,the catalyst dosage was 0.75 g/L and the initial PNP concentration of was 10 mg/L,the removal rate was 99.99%after 180 min.The Cu-Fe-PAN catalyst showed a higher catalytic performance under the same photocatalytic conditions than Fe-PAN.After the Fe-PAN catalyst was regenerated and used for 5 times,the removal rate of PNP could still reach more than 90%,and the metal ions leaching of Fe3+ and Cu2+ was better than Fe-PAN,which indicated that Cu-Fe-PAN catalyst had a better stability and reutilization performance in comparison to the Fe-PAN catalyst.