| Lead dioxide has good conductivity,good chemical stability,high oxygen evolution potential similar to metal,and has good removal effect on organic pollutants in water treatment,avoiding water pollution caused by a large number of lead ions produced by corrosion of lead-based electrode in use.The Ti/PbO2 coated electrode made by electrodeposition has the advantages of convenient fabrication and stable size,but its short working life?the actual service life converted from accelerated test is only hundreds of hours?is poor in durability,poor coating adhesion,low electrode electrocatalytic activity and other problems can not meet the requirements of actual working conditions.Therefore,this study aims at the above problems in two aspects:on the one hand,the arc spraying technology is used to introduce nitride with good conductivity and excellent corrosion resistance as the intermediate layer to enhance the bonding strength between titanium base and active layer to improve the electrode stability;on the other hand,on the basis of two-dimensional plate,SnO2-Sb/GAC is used as the particle electrode to form a three-dimensional electrode electrocatalytic reactor,To improve the electrocatalytic activity of the electrode.The research results will contribute to the breakthrough of the preparation technology of long-life and high-efficiency titanium based PbO2 anode,and promote the practical and reliable treatment of biorefractory organic wastewater by electrochemical oxidation technology,making it an important alternative technology for environmental protection engineering.The main conclusions are as follows:?1?The introduction of ZrN can effectively promote the growth of PbO2,refine the surface grain,increase the specific surface area and catalytic activity of the electrode.In the degradation of phenol simulated wastewater,the removal rate of phenol and COD in 180min is 11.98%and 13.47%higher than that of Ti/PbO2electrode without interlayer,respectively.?2?The stability of Ti/ZrN/PbO2 electrode prepared by the introduction of zirconate intermediate layer is greatly improved compared with that of Ti/PbO2electrode without intermediate layer,and the accelerated test life of Ti/ZrN/PbO2electrode is nearly 7 times longer than that of Ti/PbO2 electrode.The main reason is that the introduction of zirconate intermediate layer has good conductivity,strong binding ability and barrier effect.?3?In the three-dimensional electrode reactor,add 300ml of methylene blue simulated wastewater with initial concentration of 80mg/L,control the distance between anode and cathode of 4cm,add 0.25mol/L Na2SO4 as electrolyte,control the current intensity of 10mA/cm2,respectively,add 8g of SnO2-Sb/GAC particle electrode to the reaction tank,under the condition of pH=8 and temperature control of25±2?,carry out electrocatalytic oxidation degradation experiment for 60min,and repeat operation 20 times,for the stability and repeatability analysis of particle electrode,the removal rate of methylene blue decreased only 4.6%,which proved the stability of particle electrode.?4?With Ti/ZrN/PbO2 as anode,stainless steel plate as cathode and SnO2-Sb/GAC as particle electrode,a three-dimensional electrode reactor was formed.When the waste water volume of fixed treatment is 300ml,the dosage of particle electrode is9g,the current density is 15mA/cm2,the temperature is 25?,the concentration of electrolyte Na2SO4 is 0.15mol/L,and the pH is slightly acidic?pH Under the condition of 3-6?,controlling the distance between the anode and cathode to 4cm and conducting electrocatalytic oxidation degradation experiment for 60min can effectively treat the simulated wastewater of methylene blue with initial concentration of 80mg/L.the removal rate of methylene blue and COD is 93.4%and 78.6%,which is significantly higher than 65.5%and 54.5%of the two-dimensional electrode system without particle electrode,and the corresponding energy consumption is from 175.3%kWh/kg decreased to 142.6kWh/kg by 19%. |
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