Treatment Of Dye Wastewater Using Micron Iron Base On The Core-shell Model Of Fe@Fe₃O_4+x

As an advanced oxidation technology, Fenton reagent is wildly applied for the study of the treatment of the industrial organic wastewater which is high organic-containing, hard-degradable, venenous and harmful, and remarkable results has been attained. The applications of Fenton reagent in treatment of coking wastewater, landfill leachate, printing and dyeing wastewater, pesticide wastewater are very effective.The traditional Fenton oxidation process always needs solution with pH value under 3 in treatment of wastewater, this limits its application. The adjusting of pH can also improve the salinity of the treated wastewater. The ways to widen pH range in Fenton process are discussed in this paper, with the advances of several methods reviewed such as using chelates, iron-like ions or solid catalysts. Some problems which ought to be deeper in research are also pointed out.In this research, a new micron core-shell catalyst Fe@Fe3O4+x was prepared of by NaBH4 reductive methods. The catalyst showed higher activity for the removal of dye wastewater than the traditional Fenton method.Both nano and micron standard catalysts were produced separetly under different methods. The core-shell structures were also proved by SEM and XRD.The Fenton reagent with nano core-shell Fe@Fe2O3 as catalyst was used in treating Reactive Brilliant Red X-3B dye wastwater. Under the condition of pH=7, [H2O2]=30mmol/L, consentration of dye wastewater as 200ppm, the removal efficiency of chroma could be as high as 80% with 2 hours treating period. While during the research, we found out that the nano-catalyst could not be recycled and reused, meanwhile the producing and stockpile were also quite inconvenient for its high activity.And the Fenton reagent with micron core-shell Fe@Fe3O4+x as catalyst was also used in treating Reactive Brilliant Red X-3B dye wastwater. The effects of the initial pH, dosage of H2O2, and initial concentration of dye wastewater were investigated. The results indicated that the optimal H2O2 dosage was 30mmol/L. The catalyst exhibited good catalytic activity when initial solution pH varied from 3 to 9. Dye wastewater was discolored effectivly.Under the condition of pH=9, [H2O2]=30mmol/L, consentration of dye wastewater as 200ppm, the removal efficiency of chroma could approach to 93% which is ten times of the effect of the traditional Fenton reagent with 2 hours treating period. And the catalyst could be easily recycled and reused for its magnetism. Using the catalyst which was already used ten times, the removal efficiency of chroma could be as high as 80%.Reaction Kinetics was also researched. Due to the advantages of the catalyst, the Fenton system using Micron Iron Base on the Core-shell Model of Fe@Fe3O4+x could be widly improved and applied in the wastewater treatment industry.