Study On The Performance Of Nitrogen-Doped Modified Electro-Fenton Cathode For Coking Wastewater Degradation

Coking wastewater,a kind of industrial wastewater,is difficult to degrade,and harmful to human.Its composition is very complex,including phenol,cyanide,benzene,ammonia nitrogen and other toxic and harmful substances.How to effectively treat coking wastewater has become the focus of research.Due to the advantages of electro-Fenton such as high efficiency and no secondary pollution,this technology has been widely concerned and studied.In this work,electro-Fenton technology was used to treat coking wastewater.Firstly,h-NPAC@AC@GR electrode and Fe@h-NPAC@AC@GR electrode were prepared.Pyridine nitrogen and pyrrole nitrogen were found in both h-NPAC@AC@GR electrodes and Fe@h-NPAC@AC@GR electrodes.Hydrogen peroxide could be generated from O₂by electro catalysis by the pyridine nitrogen,resulting the increasing of hydroxyl radical concentration.In addition,the loading of iron oxide can reduce the formation of iron mud in the system.Specific research contents and conclusions are as follows:The degradation of coking wastewater by electro-Fenton with h-NPAC@AC@GR electrode was carried out.And the effect of electrode area,current density,p H of reaction system and catalyst(Fe²⁺)concentration on COD removal rate were investigated.The removal rate of COD increased with the increase of degradation time.As the electrode area increases gradually,the removal rate increases.Under the condition p H=3,current density is 25 m A/cm²,Fe²⁺is0.7m M,the removal rate of COD can reach 86%,and the reaction complies with the first order reaction kinetics.The degradation of coking wastewater by electro-Fenton with Fe@h-NPAC@AC@GR electrode was carried out.And the effect of electrode area,current density,p H of reaction system,concentration of loaded iron and electrolyte concentration on COD removal rate were investigated,The removal rate of COD increased with the increase of degradation time.As the electrode area gradually increases.Under the condition p H=3,current density of 25m A/cm²,iron loading of2.1m M,the COD removal rate can reaches 93%.