Degradation Of 4-CP Simulated Wastewater Using PbO₂ Electrode Prepared By Cyclic Voltammetry

The structure and composition of electrode have an important effect on the electrocatalytic characteristics and life-time.This work focused on the preparation of fluorine doped lead dioxide electrodes using cyclic voltammetry in different solution and at different temperature.Taking 4-CP as model pollutant,oxidative degradation experiments were done using the prepared electrodes as anode.The fluorine doped lead dioxide electrodes were characterized by X-ray diffraction and scanning electron micrograph.The results demonstrated that the primary substance on outer layer of the electrodes prepared in Na OH solution was ?-PbO₂,with symmetrical structure.The primary substance on outer layer of the electrodes prepared in HNO₃ solution was ?-PbO₂,with a compact and symmetrical structure.Different from the case in Na OH and HNO₃ solution,the primary substance on outer layer of the electrodes prepared in Na HCO₃ solution was a mixture of ?-PbO₂ and ?-PbO₂.As a consequence,the electrode prepared in HNO₃ solution and at 65? was selected as an ideal electrode,because the ?-PbO₂ is believed to has the best electro-catalytic characteristic.The effects of various operating variables,such as current density,initial p H value,initial 4-CP concentration and temperature on the 4-CP degradation were investigated.After 24 h reaction,the total organic carbon?TOC?removal rate was about 89.2% at a current density of 25 m A?cm-2,initial 4-CP concentration of 0.5 mmol?L-1,a p H of 6.0 and a temperature of 65?.The results showed that the TOC removal efficiency increased with the increase of current density,and decreased with the the increase of initial 4-CP concentration.The initial p H of the solution has negligible influence on 4-CP mineralization.A possible reaction pathway was proposed based on the analys of High Performance Liquid Chromatography.Ion Chromatography and Gas Chromatography and Mass Spectrometry.For the purpose of practical application,a electrolytic reaction was designed using PbO₂ as working electrode and titanium-based electrode as counter electrode.Total investment,operating costs and processing costs were analyzed.With further improvement,the designed reactor can be appled to simple industrial handling.