Enhancement Of Fenton Processes For The Degradation Of Organic Pollutants With Fe@Fe₂O₃ And Fe@FeS Core-shell Nanomaterials

The study proposes a method for degrading antibiotics under neutral conditions with a combination of zero-valent iron core-shell nanomaterials and Fenton's reagent.We selected Fe@FeS and Fe@Fe₂O₃ core-shell nanomaterials for comparative analysis to treat the degradation of organic pollutant antibiotics.Norfloxacin is discharged into the water and is difficult to remove completely using traditional water treatment methods.p-ASA is not broken down in animals.Entering the water body will cause pollution because the animal's urine and feces are excreted.p-ASA will be converted to highly toxic trivalent arsenic.Therefore,this study selected two antibiotics for experimental research,the results are as follows:The TEM,SEM,XRD and other means of material characterization,Fe@FeS and Fe@Fe₂O₃ core-shell nanomaterials consist of a large number of irregular spherical particles or strip structure.The TEM,SEM,XRD and other means of material characterization,Fe@FeS and Fe@Fe₂O₃ core-shell nanomaterials consist of a large number of irregular spherical particles or strip structure.The Fe@FeS and Fe@Fe₂O₃core-shell nanomaterials reacted into a floc structure because the material produced oxides or hydroxides on the surface during the reaction;Through degradation test,pH test and cycle test,it can be concluded that the degradation effects of norfloxacin or p-ASA are over 95%,and the recovery rates of both materials are over 89%,and the degradation is still above 84%.In the degradation process of norfloxacin or p-ASA,the reaction system produces a large number of hydroxyl radicals,which is consistent with the degradation trend.The Fe@FeS and Fe@Fe₂O₃ core-shell nanomaterials can promote a large amount of superoxide anion generated by Fenton reaction,which can convert divalent iron ions and ferric ions,and increase the content of ferrous ions during the reaction.The Fenton reaction is continuously cycled and the reaction time is extended;GC-MS is used to detect the intermediate products produced by the degradation of norfloxacin in Fe@FeS/Fe²⁺/H₂O₂ system,mainly including 2-methylethylidenebenzene,pentamethylbenzeneand and 2-methylnaphthalene;The intermediate products produced by the degradation of norfloxacin in the Fe@Fe₂O₃/Fe²⁺/H₂O₂ system were mainly detected,2,4,6,8,10-tetradecosapentaenoic acid,1,3-dimethylbenzene,adjacent Diethyl phthalate,n-hexadecanoic acid,erucic acid,etc.;LC-MS is used to detect the intermediate products produced by the degradation of p-aminophenyl arsenate in the Fe@Fe₂O₃/Fe²⁺/H₂O₂ system,mainly hydroquinone,p-benzoquinone,maleic acid,and formic acid;Almost all p-aminobenzene arsenate is converted to As???and NH⁴⁺;FTIR analysis of two materials detected carbon triple bond,carbon-carbon double bond,benzene ring,AR-OH phenol,carbon-oxygen single bond,etc.;The UV absorption spectrum of the degradation process of norfloxacin in Fe@FeS/Fe²⁺/H₂O₂(Fe@Fe₂O₃/Fe²⁺/H₂O₂)system can be used to prove that the maximum absorption peak at 273 nm is reduced and blue shift occurs.The second step is the ring opening of the benzene ring,the intermediate product is further degraded by small molecules,and finally,all small molecules can be degraded into carbon dioxide and water;The UV absorption spectrum of the degradation process of p-aminophenyl arsenic acid in the Fe@Fe₂O₃/Fe²⁺/H₂O₂ system shows that the maximum absorption peak at 450 nm decreases and blue shift occurs.The second step is the ring opening of the benzene ring,the intermediate product is further degraded by small molecules,and finally,all small molecules can be degraded into carbon dioxide and water;However,the presence of sulfur in the Fe@FeS core-shell nanomaterials may participate in the reaction with hydrogen peroxide or water to produce sulfur ions and sulfate ions;Fe@FeS and Fe@Fe₂O₃ core-shell material Fe⁰ core uses two electrons to generate hydrogen peroxide,reducing molecular oxygen to make Fe²⁺ions on the surface of the material generate superoxide anion to promote the conversion of Fe²⁺and Fe³⁺,so that Fenton reaction can be cycled.Through the experimental results,we found that the new neutral Fenton process can be used as a simple and effective method for treating organic wastewater,which can be further expanded to deal with more difficult to treat pollutants.