Study On The Treatment Of The Process And Mechanism With Copper And Organic Wastewater By Electro-fenton Coupled Pulsed Alternating Current Coagulation

The treatment of the wastewater containing heavy metal and refractory organics possesses some difficulty in the field of industrial wastewater.When the heavy metal wastewater mixed with organics,the treatment of the complicated wastewater becomes more difficult.Organic wastewater containing heavy metals widely exists in electroplating bath,metallurgy wastewater,printing and dyeing industry and other industrial fields.Some techniques have been used to remove metal pollutants from wastewater,including chemical precipitation,replacement-coprecipitation,adsorption,coagulation and flocculation.Chemical coagulation has the advantages of simple,fast,high efficiency and low operation cost in the treatment of industrial wastewater,but it produces a lot of sludge,which is easy to cause serious secondary pollution.Electro-coagulation（EC）and Electro-Fenton（EF）is an environmentally friendly wastewater treatment technology.The removal of inorganic and organic pollutants from wastewater by EC and EF.（1）Electro-Fenton（EF）coupled with Pulsed alternating current coagulation（PACC）is an effective technology for the treatment of Cu²⁺-organic wastewater.In this study,the removal efficiency（R_e）,electrical energy consumption（EEC）and removal mechanism of Cu²⁺-organic were analyzed and the optimal operation parameters were determined.The results show that under the optimal conditions of initial pH=2.5,electrode voltage（E）=3 V,initial c(Cu²⁺)=50 mg·dm^-3,c（COD）=500 mg·dm^-3,c（H₂O₂）=0.1 mol·dm^-3,frequency（f）=1 Hz,t=20 min,the R_e(Cu²⁺)can reach 99.59%.R_e（COD）is 90.21%,EEC is 0.1695 kWh·m^-3,and the amount of produced sludge（W_s）is 0.9283 kg·m^-3.（2）Treatment of methylene blue wastewater using pulsed electro-Fenton,determine the best operating conditions.At the optimum initial pH=2.5,initial c（MB）=200 mg·dm^-3,its organic content c（COD）=350 mg·dm^-3,c（H₂O₂）=25 mmol·dm^-3.Pulse parameter is voltage E=3 V,frequency f=1 Hz,duty cycle γ=100%treatment is the best,methylene blue color removal 100%,R_e（COD）is 60.32%.（3）The removal mechanism of methylene blue and Cu²⁺-organic was analyzed,SEM,EDS,XRD and FTIR were used to characterize the morphology,elemental composition,crystal structure,function groups of sludge produced in the Cu²⁺-organicand and methylene blue compound wastewater.UV,ESR and GC-MS were used to describe the degradation process of organic matter in EF-PACC.（4）Compared with single EF and PACC processes,the order of treatment efficiency is EF-PACC>EF>PACC.Economic efficiency analysis shows that EF-PACC technique has a good application prospect in the treatment of Cu²⁺-organicand and methylene blue compound wastewater.The EF-PACC coupled process includes that electrolyzed Fe³⁺produces electrocoagulation and·OH produces degradation of organic compounds.The interactio n of the two effects can remove Cu²⁺-organic from wastewater effectively.