| A novel lead dioxide electrode modified by manganic mineral was prepared by high pressure molding. The composition, surface morphology, oxidation capability and life of anode were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), cyclic voltammetry and accelerating life test. The results show that main composition of electrode isβ-PbO2 and there ware many small holes on the electrode surface,and the produce-oxygen voltage, electric capability, stability and life of electrode could be improved by doping a certain amount of manganic mineral.We use this new electrode as anode, and regard the stainless steel plate as cathode to degrade stimulant waste water, namely bisphenol A and weak acid pink dye BS, in a no dissepimental electrolytic cell. The factors such as quantity of manganic mineral, current density, pH, initial concentration of the organic solution, and type of assistant electrolyte are studied in the process of degrading waste water. Solution composition especially intermediates product was analyzed by means of Uv-Vis and GC-MS. The results reveal that the conversion rate of BPA and BS are increased as the increasing of the reaction time and current density, are decreased as increasing the initial concentration of the organic solution. Electrolysis of BPA and BS in acidic or alkali solution was more efficient than in neutral solution. Different electrolyte had different influence to the electrolysis of dyes on lead dioxide anode, considering color and COD removal rate, electrolysis in NaCl solution is the most efficient. By electrolysis on lead dioxide anode, BPA and BS cannot be totally decomposed into CO2 and H2O, but can be turned into smaller and simpler aromatic compounds containing hydroxyl or carbonyl and hydrocarbon compounds.Further, the mechanism of electrolysis on lead dioxide anode is also discussed. Hydroxyl is formed during the oxidation of water on lead dioxide electrode and participates in the degradation of organic substance.
|
PDF Full Text Request