Research On Electrochemical Degradation Of Organic Wastewater Using A New Lead Dioxide Electrode

In this work, a novel porous lead dioxide electrode was prepared by high pressure molding technique,which choosed lead dioxide electrode as the substrate. Thus,we obtained?B₄C/C?-?-PbO₂ electrode by doping boron carbide and graphite, and ?CeO₂/C?-?-PbO₂ electrode by doping cerium oxide and graphite. Electrochemical capacity of modified electrode was characterized by scanning electrode microscopy ?SEM?, X-ray diffraction?XRD?,cyclic voltammetry ?CV?,polarization curves ?LV? and corrosion resistance test.Results indicated that the homemade lead dioxide was ?-PbO₂; the surface of pure ?-PbO₂ electrode was uniform and modified electrode was more loose, had larger effective area and was beneficial for the electrochemical degradation. And electrocatalytic oxidation capacity of modified electrode was much higher than the pure electrode. In addition,doping modification greatly improved the stability and the service life of electrode.The homemade ?B₄C/C?-?-PbO₂ electrode was served as anode and accompained by steel plate electrode as the cathode for the treatment of tetracycline hydrochloride ?TCH?simulated industrial wastewater. Key parameters of TCH degradation including doping amount, initial TCH concentration, electrode gap, current density, pH, and electrolyte concentration were detailed investigated. The degradation products on the basis of the UV-Vis scanning spectru. Results showed that 20%?B₄C/C?-?-PbO₂ electrode held the best electrochemical performance, pseudo-first-order kinetics equation was followed during electrocatalytic degradation of TCH. The maximum removal rate of TCH was 90.87% on the condition that initial concentration was 300 mg L-1 , Na2SO4 concentration was 0.2 mol L-1,electrode spacing was 1 cm,current density was 30 mA cm-2 and pH was 3 after 120 min. All these results indicated that ?B₄C/C?-?-PbO₂ electrode could effectively removeTCH and had potential in industrial applications.The homemade ?CeO₂/C?-?-PbO₂ electrode and the same area of steel plate electrode worked as anode and cathode,respectively, for the electro-catalytic degradation of high-salinity and high-concentration reactive brilliant red X-3B ?RBR X-3B? simulated dye wastewater. Effects of experimental parameters,including electrolyte concentration,pH,current density and electrode gap on the decolorization rate, the removal rate of COD and ammonia nitrogen were systematically investigated. Results indicated that when the doping amount was 20%, the electrode had the best electrocatalytic performance; the electrocatalytic degradation conformed to the first order linear equation. The optimum experimental parameters of electrochemical oxidation were obtained on the condention that NaCl concentration, current density, pH, electrode gap was 6 g L-1, 30 mA cm-2, 10.02, 1 cm and 60 min of treatment of 2000 mg L-1 RBR X-3B. Under these conditions, decolorization rate, COD and ammonia nitrogen removal rate reached 99.27%, 66.34% and 80.26%. All these results indicated that (CeO₂/C?-PbO₂ electrode could efficiently treat high-salinity and high-concentration dye waste water and thus had industrial applications.