Electro-fenton Degradation Of Organic Dye Wastewater By Nickel Foam Cathode

In recent years,Fenton oxidation technology,a kind of advanced oxidation process,has attracted extensive attention due to its high degradation rate,high maneuverability and low input cost.However,traditional Fenton method still has many shortcomings in practical application,including:?1?High price,storage and transportation problems of hydrogen peroxide.In practical applications,hydrogen peroxide is added to keep the reaction going because of constant consumption;?2?Production of iron sludge;?3?Low utilization ratio of the catalyst and no effective cycle of Fe³⁺/Fe²⁺.To further improve the shortcomings of traditional fenton oxidation technology,experiments were designed to optimize and explore the degradation conditions,influencing factors and efficient hydrogen peroxide production mechanism of dyes with nickel foam as cathode or auxiliary material.1.Using photoelectric-Fenton oxidation technology,the malachite green organic dye was degraded by dispersive way of Fe₃O₄ prepared by sodium borohydride reduction method with nickel foam as cathode.To improve the utilization ratio of catalyst and reduce or avoid the production of iron sludge,the regeneration of Fe²⁺was promoted by light.The results showed that photoelectric-Fenton showed the highest degradation ratio in different oxidation comparison experiments,and the degradation ratio reached 76.19%in only 30 min.In addition,the reutilization ratio of Fe³⁺/Fe²⁺cycle was also well demonstrated in electrode,Fe₃O₄ reusing degradation of dyes and iron ion cycling experiments.2.Rhodamine B organic dyes were degraded by using electro-Fenton oxidation technology with nickel foam loaded with cucumber bionic Fe₃O₄ as cathode.The results showed that the degradation ratio of the rhodamine B dye reached the maximum 81.8%in 50 min,when the cucumber biomimetic Fe₃O₄/PTFE composite electrode was used.However,in the experiments of exploring the repeated utilization ratio of the electrode and the change of iron ion concentration in the solution,it was found that when the electrode material was repeatedly used for the fourth time,the degradation ratio of the solution was decreased to 21.7%,which was only a quarter of the initial degradation ratio.The results also proved that the composite electrode with supported catalyst on nickel foam had poor stability and low catalyst utilization.3.The mechanism of spontaneous production of hydrogen peroxide without electricity or added hydrogen peroxide by using foamed nickel as auxiliary material was studied.A fast,efficient and spontaneous production method of hydrogen peroxide was put forword.The method can avoid transportation and storage problems of hydrogen peroxide in traditional Fenton technology.The results showed that the production concentration of hydrogen peroxide could reach 1026.2?mol/L under the acidic and oxygenated condition for 120 min,which was a high production rate of hydrogen peroxide.