Study On Preparation Of Activated Carbon Catalytic Particle Electrode And Electrocatalytic Oxidation Degradation Of Acid Red B

In this paper, several activated carbon particle electrode carriers and catalytic metal elements were studied. The catalytic particle electrodes loaded different catalytic metal elements were prepared by impregnation-calcination method. The electrocatalytic oxidation efficiencies of the particle electrodes were evaluated. The material properties of catalytic particle electrodes were determined by scanning electron microscopy and energy dispersive spectroscopy (SEM-EDS), N2 adsorption desorption curves, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS). And the effects by the electrochemical conditions were studied. Finally the degradation path of AR-B by catalytic particle electrodes were put forward. The results were as follows:The study on particle electrode carriers showed that nut shell activated carbon (NSAC) was selected as the most suitable particle electrode carrier due to its best adsorption properties. During the comparation of single element and composite elements, the treatment effects of AR-B concentration and COD, the crystal structure of catalytic componment, and unit COD energy consumption were compared comprehensively. Finally the Fe and Co composite elements were selected as the catalytic component.When the impregnating solution concentration was 0.3 mol/L, the mole ratio of composite elements was 1:1, soaking for two times, and the soaking time was 8 h, the Fe-Co/NSAC prepared under this condition degraded AR-B concentration and COD in the average removal efficiency of 90.2% and 92.8%, respectively. Compared to NSAC, which were about 18.4% and 20.6% enhanced, respectively.The results of SEM-EDS showed that catalytic elements loaded uniformly on the surface of NSAC. ICP-OES indicated that the mass percentage of elemental Fe and Co were 6.4wt% and 2.9wt%, respectively. N2 adsorption desorption curves illustrated the adsorption behavior and pore size distribution of NSAC did not change significantly after loading, the pore size distribution was mainly micropores. The results of XRD and XPS spectra showed that the main component of catalytic component was CoFe2O4.The reasearches on electrochemical conditions showed that when the electrolyte was 0.03 mol/L Na2SO4 solution, the current was 0.10 A, hydraulic retention time was 20 min, initial solution pH was 7, treatment effect of AR-B wastewater by Fe-Co/NSAC was optimal stabilized. AR-B concentration and COD of effluent were maintained in 9.4-12.0 mg/L and 9.6～11.8 mg/L, respectively, and the average removal efficiency could reach 97% and 94%, respectively. The results of N2 adsorption desorption curves and pore size distribution indicated that the catalytic particle electrode could maintain good pore structure after long-term use.The results of UV-vis spectra, fluorescence spectra and gas chromatography-mass spectrometry showed that azo bond was interrupted in the degradation process of AR-B.The naphthalene compounds were produced and then further oxidized to organic acids, ketones, or hydrocarbons, which containing a benzene ring, finally they were degraded into small molecular organic acid, carbon dioxide and water.