Preparation Of Glucose Modified Iron Oxide And Its Fenton Catalytic Performance

Over the past decades,the treatment of toxic organic pollutants such as organic dyesand pesticides have received considerable attention due to theirdetrimental effects on the environment and human health.These pollutants usually cannot be effectively removed by conventional physicochemical and biological wastewater treatment processes.Advanced oxidation processes,which can generate hydroxyl radicals(·OH)from non-selective oxidation of organic pollutants,are well recognized as a promising technology for wastewater treatment.Among them,the heterogeneous Fenton technologyhas been widely applied to the degradation of organic pollutants.It was found that the addition of some organic ligands in the catalyst suspensions could enhance the degradation of organic pollutants.In this paper,the preparation,structure and catalytic properties of three kinds of iron-based catalysts for glucose modification were systematically studied.Mainly includes the following three aspects:(1)Preparation of Fe3O4-Glc and its Fenton catalytic performanceGlucose-modified Fe3O4 nanomaterials were synthesized by water bath method in this chapter.The effects of glucose modification on the structure,surface charge,electron transfer ability,specific surface area and catalytic activity of Fe3O4 were studied.The results showthat:Fe3O4 modified with glucose showed better Fenton catalytic activity for methylene blue;The reason for the increase in activity may be related to the reduction of glucose.Because the addition of glucose can increase the proportion of Fe2+ on the surface of Fe3O4,and it is conducive to generating more·OH.(2)Preparation of amorphous iron oxide and its Fenton catalytic performanceA series of glucose-modified iron oxides were synthesized by hydrothermal method in this chapter,which included changing the dosage of glucose,reaction temperature and hydrothermal time.In this chapter we used phenol as a simulated pollutant to study the catalytic activity of the polyphase Fentoncatalyst,and determined the optimum synthesis conditions.The effects of pH,H2O2 concentration and catalyst dosage on the degradation efficiency were further investigated,and the optimum reaction conditions were determined.Since the initial pH of phenol has a great effect on the degradation effect,thechange of pH and the production of ·OH in each time period during the Fenton reaction are studied.The results show that the decrease of pH is beneficial to the formation of ·OH,and the contribution of homogeneous Fenton in the process of phenol degradation also increases.(3)Preparation of amorphous Fe-Zn composite oxide and its visible light Fenton performanceThe amorphous Fe-Zn composite oxide was synthesized by hydrothermal method in this chapter.The structure,composition and valence of the catalyst were determined by various characterization techniques.The results show that:The catalyst exhibits good visible Fenton activity for various pollutants;The reaction mechanism was deduced by free radical trapping experiments at different pH values.The degradation of RhB was mainly due to the reaction of RhB with H2O2 at pH = 6.5,and the contribution of ·OH increased with the decrease of reaction pH;However,the·OH in solution is the main active species for the degradation of phenol;In addition,·OH mainly comes from the direct reaction of photogenerated electrons and H2O2.