Study On Fe-N Doped SBA-15 And Carbon Black And Their Application Ih Catalytic Oxidative Degradation Of Organic Pollutants

the development of economy and society,a number of degradation-resistant and toxic pollutants have emerged,such as endocrine disruptors,antibiotics and pesticides.These pollutants are difficult to be degraded by traditional physicochemical methods or biological methods.If the pollutants were not handled properly,it will seriously threaten human health and restrict the development of our country.Fenton reaction,one of the advanced oxidation processes(AOPs),was intensively concerned and investigated because it could degrade even completely mineralize degradation-resistant organics through generating radicals.However,conventional AOPs have such shortcomings as low efficiency of utilization of H2O2,narrow pH range and large amounts of sludge.Therefore,it is urgent to explore and improve economical,effective and environmental-friendly techniques.In this paper,we prepared peroxymonosulfate(PMS)and hydrogen peroxide catalysts by loading Fe-N complexes into mesoporous material SBA-15 and carbon black.The main contents of this work are shown as follow.(1)We prepared highly efficient peroxymonosulfate catalysts with chelate of FeCl3 and imidazole loaded in SBA-15.The Fe-Im-SBA/PMS system presents an extraordinarily catalytic activity for Rh B removal by PMS activation.The removal rate of 50 ppm RhB reached up to 95%within 5 min and 99%within 10 min.The efficiency of Fe-Im-SBA/PMS system is higher than the graphitized mesoporous carbon/PMS,multi-walled carbon nanotubes/PMS and activated carbon/PMS.Moreover,Fe-Im-SBA performed well in a wide pH range with complete removal of Rh B in pH ranged from 0.5 to 10.1O2 is the major reactive oxygen species in the systems,which is the reason of the selectivity of the PMS/Fe-Im-SBA oxidation.The Fe-N4 sites and Fe2-N2 sites are proven to be the active matters in Fe-Im-SBA by characterization.Fe-Im-SBA/PMS reaction system can be applied to selectively degrade target contaminants in the presence of backgr,ound organics(such as natural organic matter)to increase the use efficiency of oxidants.(2)We prepared efficient hydrogen peroxide catalysts with chelate of FeCl3 and imidazole loaded in carbon black.Fe-Im-C can acvtivate hydrogen peroxide to completely degradade 50 ppm Rh B in 30 min under the conditions of pH = 3,catalyst dosage of 0.8 g/L and H2O2 concentration of 100 mM.The Fe-Im-C/H2O2 system can also oxidate other organics like AR 73,BPA,2,4-DCP and benzoic acid through the generation of hydroxyl radicals.The characterization of the catalyst showed that the active components of the catalyst were Fe-N and FeO.