The Modification Research Of Novel Lead Dioxide Electrode And Its Electric-catalytic Performance Research

In the experiment a new-type PbO2 electrode preparation technology was studied. Mixing graphite powder, cerium oxide powder, polytetrafluoroethylene (PTFE) and the homemade ?-PbO2 powder,(CeO2/C)-?-PbO2-PTFE composite electrodes was made by the high pressure molding technique.The surface structure and electrical property of the electrodes was characterized by using scanning electron microscopy(SEM) and the cyclic voltammetry curves (CV). Measured results show that (CeO2/C)-?-PbO2-PTFE composite electrode has higher activity and catalytic performance than ?-PbO2-PTFE electrodes.The (CeO2/C)-?-PbO2-PTFE composite electrode was applied to treat a simulative dyeing wastewater of reactive brilliant red X-3B with electrolyte sodium sulfate. The results showed that the 20%(CeO2/C)-?-PbO2-PTFE composite electrode was well in treating the wastewater at conditions of initial pH 2, reactive brilliant red X-3B initial concentration 100 mg L-1, Na2SO4 concentration 0.35 mol L-1, the constant current density 30 mA cm-2, and spacing value 1.5 cm. After electrolytic time of 90 min, the maximum de-colorization and chemical oxygen demand (COD) removal rates reached 88.92% and 54.54% respectively. And the de-colorization rate of reactive brilliant red X-3B was in conformity with pseudo-first-order kinetics equation. The degradation mechanism of reactive brilliant red X-3B was discussed in terms of analyzing the possible intermediates and degradation pathway with LC-MS.The electrode was also applied to treat another simulative dyeing wastewater of high concentrations of reactive brilliant red X-3B with high salty. The effects of NaCl concentration, electrolyte pH, spacing value and current density on degrading simulative dyeing wastewater were studied. The results showed that the optimal conditions are RBR X-3B concentration 2000 mg L-1, NaCl concentration 6 g L-1, constant current density 30 mA cm-2, spacing value 1.0 cm and electrolyte pH 2.09. Meanwhile, under common experimental conditions of RBR X-3B concentration 2000 mg L-1, NaCl concentration 4.5g L-1, constant current density 30 mA cm-2, spacing value 3.0 cm and electrolyte pH 5.76, its de-colorization rate, COD removal rate and electrode current efficiency could reach 97.34%,54.21% and 37.53% respectively after electrolysis 60 min. The experimental results showed that 20% (CeO2/C)-?-PbO2-PTFE electrode has certain industrial application prospect in treating dye wastewater with high salty and high concentration.