Preparation And Catalytic Performance Of PVDF Porous Fiber-Fe₃O₄ Composite Heterogeneous Fenton Catalyst

With the rapid economic development,industrialization has brought a huge impact on our lives and the environment,and the treatment of industrial wastewater containing organic dyes has become a very difficult problem.Fenton reaction is an efficient technique for removing difficult-to-degrade organic pollutants.Therefore,the synthesis and performance of heterogeneous Fenton catalysts have gradually become a hot spot for researchers.In this study,Fe₃O₄/PVDF fiber was prepared by wet spinning with a single-hole needle to treat wastewater simulated by Rhodamine B(Rh B).The influences of reaction factors on the catalytic oxidation of Fe₃O₄/PVDF fibers were discussed in detail,including the dosage of H₂O₂,the loading of Fe₃O₄nanoparticles and the initial p H value of the solution.Explore the catalytic efficiency of Fe₃O₄/PVDF fiber under optimal reaction conditions.In order to further study the effect of the combination of membrane separation and Fenton oxidation technology on catalytic efficiency,Fe₃O₄/PVDF hollow fiber membranes were prepared by wet spinning with an integrated coaxial needle.Explore the effect of Fe₃O₄nanoparticles loading on catalytic performance in Fe₃O₄/PVDF hollow fiber membranes.Rh B simulated wastewater was used as the oxidation treatment object,and focus on the hollow fiber membrane rejection,permeability and catalytic efficiency.The study showed that:(1)The optimal catalytic reaction conditions were as follows:the initial p H value of the solution was 4.14,[Rh B]=10 mg/L,[H₂O₂]=98m M and Fe₃O₄nanoparticles loading amount was 7 wt%.Under these conditions,97.14%Rh B could be degradated by the heterogeneous Fenton oxidation for 120 min.In the stability test,after 4 cycles of testing,the degradation rate of 7 wt%Fe₃O₄/PVDF fiber was 84.41%and still maintained good catalytic activity,indicating that it has good stability and reusability.(2)The catalytic performance of the hollow fiber membrane was the best when the loading amount of Fe₃O₄nanoparticles was 10wt%.Under 0.1 MPa,the rejection rate of 10 wt%Fe₃O₄/PVDF hollow fiber membrane for Rh B was 95.3%,and the flux was 23.75 L·m^-2·h^-1.After 5 cycles of testing,the permeation flux and rejection rate of the 10 wt%Fe₃O₄/PVDF hollow fiber membrane can still be maintained in a stable state.Two heterogeneous Fenton catalysts,Fe₃O₄/PVDF fiber and Fe₃O₄/PVDF hollow fiber membrane,have good catalytic performance,which show that they have good application prospects in the field of water treatment.At the same time,the combination of membrane separation and Fenton oxidation technology also provides a new idea for the treatment of dye wastewater.