Preparation And Application Of Heterogeneous Electric-Fenton Electrode Materials

Heterogeneous electric Fenton technology in wastewater treatment has unique advantages,high degradation efficiency,no selectivity to the substrate,the H2O2 generation mechanism, pH range, easy recovery of catalyst, does not produce iron sludge etc.. This paper selects iron nitrate, nickel nitrate, copper nitrate, zinc nitrate,manganese nitrate and aluminum nitrate of six kinds of metal compounds,by dipping method respectively adsorbed on graphite felt, under the nitrogen atmosphere by high temperature calcination prepared six different carbon supported metal compounds,used as heterogeneous electric cathode materials Fenton,XRD?XPS and TG characterization of six kinds of electrode materials and the preparation was carried out by rhodamine B, at the same time as the substrate to test the six. kinds of electrode materials for heterogeneous electrical activity of Fenton.The results show that six kinds of electrode materials were prepared respectively Fe3O4/GF,Ni/GF,Cu-CuO/GF,ZnO/GF,Mg-MgO/GF and Al2O3/GF,the contents of metal elements in electrode materials were Fe (14.91wt%), Ni (25.00wt%), Cu (13.79wt%), Zn(8.50wt%), Mg (8.56wt%) and Al (4.37wt%). The heterogeneous Fenton system was constructed and six kinds of electrode materials were used as cathode and graphite rod as anode to degrade 5 mg·L-1 rhodamine B solution, the results showed that Fe3O4/GF and Ni/GF have the highest degradation, of rhodamine B close to 100% stability and repeatability of the experimental ,degradation rate,cycle is higher,Cu-CuO/GF,ZnO/GF Mg-MgO/GF, and Al2O3/GF.Taking the Ni/GF composite as the research object, the optimum preparation conditions and the mechanism of rhodamine B degradation were analyzed. The results showed that: Ni/GF (Ni2+): EDTA=1:1, drying time was 12h, the carrier was 2mm of the graphite felt(GF), the best performance of the recycled composites. When the voltage is -2V,the concentration of rhodamine B is 25 mg·L-1,the reaction time is 5h,the degradation rate of Ni/GF composite is close to 96%. The hydroxyl radical experiment found that hydroxyl radicals in Ni/GF composite degradation rhodamine B does not play a major role, but the synergistic effect of power, aeration and hydroxyl radical, the power played a major role ,secondary role is O2 and hydroxyl radical. In addition, it was found that the chemical reaction of Ni/GF composite was not found on the surface of Ni/GF composite material in the experiment. The results showed that the degradation of rhodamine B by the composite material was the process of physical adsorption under the electric induction,the adsorption capacity of Ni/GF composite is about 32mg/g.