Studies On Preparation Of Conductive-diamond Electrode And Treatment Of Chlorobenzene Wastewater

Because the electronic is added as reagent and there is no need to add other chemicals,electrochemical oxidation ontrollability and it has a stronger oxidizing ability than general chemical reaction.Electrochemical oxidation can process the poisonous and difficulty degradation organic wastewater.In the process of electrochemical oxidation,some crucial issues are related to the anodic materials,such as dynamics,electric energy consumption and the trial life of electrode.Therefore,the key issues is to choose the anodic material of good stability,good conductivity and high catalytic activity in the electrochemical industry.Conductive-diamond powder was co-deposited with nickel to form composite electrode in this paper.Conductive-diamond electrode,which can be used for stable anode,was successfully fabricated by composite electrode dip coating PVDF and polishing method.The conductive-diamond electrode possesses extremely wide potential window,extending almost 2 volts in acid,2.5volts in alkali and 1.75 volts in salt solution.Conductive-diamond electrode is 2.34 volts higher than traditional Pt electrode according to oxygen evolution polarization curve.One conclusion can be drew that conductive-diamond electrode benefits the removal of chlorobenzene(CB),and hence the degradation efficiency is higher on conductive-diamond electrode than on traditional Pt electrode.This paper uses new conductive-diamond electrode to investigate the influence of initial pH value of solution,current magnitude and electrolysis time to degradation effect of CB and TOC.In this experiment,the initial CB concentration is 100mg/L,the removal rate of TOC is 92.6%on the conductive-diamond electrode much higher than 82.5%on traditional Pt electrode under the optimal conditions than current magnitude of 15mA,electrolytic dosage of 0.5mol/L,pH value of 7.The kinetic studies of effects on current to CB degradation show that the relationship between-ln(ct/c0)and degradation time is liner,which indicates that the reaction of electrochemical degradation of CB conforms to the laws of first-order kinetic.By studying the degradation pathway of CB,it can be indicated that the process of chemical degradation of CB on the conductive-diamond electrode.It was found that after chloric substituent was removed,the products could be degraded into low molecular organic acids,such as oxalic acid,malonic acid,fumaric acid,malic acid and so on.Then these low molecular organic acids were mineralized into CO2,however the mineralization rate was lower than the degradation rate of CB obviously.