Modification Of PAN-based Activated Carbon Fiber And Its Adsorption And Degradation Properties For P-nitrophenol

P-nitrophenol(PNP),which is light yellow crystal,tasteless,slightly soluble in water at room temperature.It has wide application in industry.It is also a refractory and dangerous substance with enrichment effect in wastewater,which may cause potential harm to aquatic organisms and human health.Active carbon fiber(ACF)is a new generation of highly efficient active adsorption engineering materials with high performance,stable performance and wide application.It has a large specific surface area,a large number of micropores,a narrow pore size distribution,a rich surface functional group and other good structure.So.it has a strong adsorption capacity.In this paper,PAN-based activated carbon fiber(PAN-ACF)was used as the research object,which was modified by oxalic acid,loaded with nano-TiO2 and Nano-ZnO photocatalyst.and adsorbed and degraded PNP by microwave catalytic wet oxidation.Then we discussed it impacting on PNP adsorption degradation performance.The PAN-ACF was modified by loading different concentrations of oxalic acid solution to prepare carboxylated activated carbon fibers.The adsorption capacity of PNP by PAN-ACF modified by oxalic acid showed a trend of increasing first and then decreasing with the increase of the concentration of oxalic acid solution.PAN-ACF was modified by impregnation with 0.5 mol/L oxalic acid solution,and it was found to have the best adsorption effect on PNP,and its adsorption rate was 98.05%.It was proved that it successfully loaded oxalic acid on PAN-ACF by means of specific surface area test,infrared test and X-ray photoelectron spectroscopy test,and the larger the concentration of oxalic acid solution,the larger the load.The main reaction of the chemisorption process is that the phenolic hydroxyl group in the PNP reacts with the carboxyl group to form an ester group.PAN-ACF/TiO2 composites and PAN-ACF/ZnO composites were prepared by loading nano-TiO2 and nano-ZnO on activated carbon fiber felt.The adsorption performance of PAN-ACF and the photocatalytic properties of nano-TiO2 and nano-ZnO have synergistic effects,and all of them have effectively treated p-nitrophenol in water.The optimum loading rates of PAN-ACF/TiO2 composites and PAN-ACF/ZnO composites were 5.83%and 2.57%,respectively.The PNP-ACF/TiO2 composite PNP with the loading rate of 5.83%has the best purification effect.Under the UV light of 254 nm with 20W/m2 intensity,the adsorption rate reaches 99.85%.The PAN-ACF/ZnO composite with a loading ratio of 2.57%has an adsorption rate of 98.31%under the ultraviolet light of 254 nm with a strength of 20 W/m2,which also achieves good results.An integrated high-pressure microwave reactor was designed and designed,and the PAN-ACF/TiO2 composite with the best performance of nano-TiO2 load ing rate of 5.83%was used.The microwave-catalyzed wet oxidation method was used to degrade PNP.The PAN-ACF/TiO2 composite catalyst has good cat alytic performance and absorbing properties,and can be used for coupling catal ysis with microwave.When using PAN-ACF/TiO2 composite as a catalyst for microwave catalytic wet oxidation to degrade PNP,temperature,power,catalyst concentration and oxidant concentration have different effects on degradation rate of PNP.As the temperature increases,the power increases,the catalyst concentration and the oxidant concentration increase,the degradation rate of PNP increases.