Study On Simultaneous Effects Of Anodic-cathodic Electrochemical Degradation For Dye Wastewater

With the rapid development of modern industry in China,the problem of water pollution has been growing,which posed threats to both the environment and human beings.Dye wastewater,as a kind of toxic and hard-degradable organic wastewater,is listed as the focus of controlling water pollution in our country.Also the method of solving dye wastewater has been become a hot issue of water treatment research.Meanwhile,with its unique qualities,electrochemical method has fantastic promising applications in the area of treating dye wastewater.Thus,this thesis systematically researches the method of dealing with methyl orange as simulated dye wastewater using electrochemistry of anodic-cathode.Also tries to analyze its acting mechanisms and reactive conditions,studying the certain rules of remove methyl orange,and provide experimental bases for the development of hard-degradable organic wastewater.The experimental facility is homemade electrochemical reactor,and the object is methyl orange as simulated dye wastewater.The research contents mainly cover selecting the electrode of electrochemical reaction,studying mono-factor-influence and response surface methodology to deal with methyl orange as simulated dye wastewater using electrochemistry of anodic-cathode at the same time,doing dynamic analyses of the degradation of methyl orange,doing mechanism analysis of the degradation of methyl orange using electrochemistry of Anodic-cathode at the same time and studying the UV-Vis spectroscopy.This experiment uses graphite,titanium dioxide plating iridium and titanium dioxide ruthenium-plated to test the anode material.Separately talks two different situations of existing chlorion and unexisting chlorion in solution.The result shows that titanium dioxide plating iridium is better than the other two anode materials in two different situations.In the best condition of anode,using graphite,steel plates and titanium to test cathode,shows that titanium is the best of all three materials.Then analyze the degradation effect of methyl orange under the optimal electrode condition with or without chlorion in solution.It turns out that the existence of chloridion can help degrade the methyl orange and is fit to be used as optimal electrode since it has the steady chemical property.In the mono-factor-influence experiment,with the increase of the Fe3+ concentration,the 3+discoloration rate of optimal electrode first increases and then decreases.The most suitable Fe3+concentration is 1mmol/L,and appropriate Cl-concentration has influence on the removal rate of methyl orange.Higher or lower is unacceptable.The current density makes sense.The greater the current density is,the higher the degradation rate and energy consuming are.The aeration rate should be chosen in a proper range to degrade methyl orange effectively.The most suitable aeration rate is 1.5L/min.The dosage of electrolyte does not much affect the overall result.The most suitable dosage of electrolyte is lg/L.With the increase of the distance between layers,the discoloration rate is decreased.This is because mediums that are so far apart have no time to transform and block the reaction.The discoloration rate of methyl orange is along with the time.Through the optimization analysis by Box-Behnken Design,the model equation of creating anodic-cathode at the same time with electronic method is R=91.19+3.47 × Fe3+ concentration-0.63 × Cl-concentration +8.55 × current density +0.4 × Fe3+ concentration × Cl" concentration-4.06 × Fe3+ concentration × current density +0.34 × Cl-concentration × current density-4.79×(Fe3+concentration)2-4.81 ×(Cl-concentration)2-5.26×(current density)2.And the optimum conditions for Fe3+ concentration is 1.02mmol/L,Cl-concentration is 10.96mmol/L,and current density is 11.52 mA/cm2.The best result of the discoloration rate is 94.6654%.The sequence according to the three-dimension curved surface of the results is as follows:current density,Fe3+ concentration,Cl-concentration.Meanwhile,that interaction between different factors which affects the discoloration rate is as follows:current density&Fe3+ concentration,current density&Cl-concentration,Fe3+ concentration&Cl-concentrationThe degradation of methyl orange under electrochemistry of Anodic-cathode at the same time fits to first order pharmacokinetic model.Different reaction factor influence rate of reaction differently.Through studying the ultraviolet-visible spectrum,we know that the concentration of methyl orange in oxidative degradation is increasingly decreased,and the effect of degradation is pretty good.Its azo form molecular,n-?*,and conjugation system from benzene ring,?-?*,have been damaged.Electrochemistry of Anodic-cathode at the same time has significant effect on the removing methyl orange,which is easily operated,takes less area,and is more energy efficient.Through further study and improvement,it can be applied to the practical engineering.