Study On Synergistic Treatment Of Land Fill Leachate By Electrochemical Oxidation/Electrocoagulation

With the rapid development of China's social economy,the urbanization process has accelerated,and the amount of household waste generated has increased substantially.A large amount of landfill leachate will be produced during the landfill filling process.Discharge at will without treatment,it will have a serious impact on the surrounding environment.In addition more stringent pollutant discharge standards place higher demands on landfill leachate treatment technology In this paper,electrochemical leachate and electro-flocculation are used to treat landfill leachate,and through the application of activated carbon fiber cathode,the Fenton technology is coupled with it to promote the degradation of pollutants in landfill leachate The experiment explored the removal efficiency of the landfill leachate,and conducted a preliminary study on the mechanism of landfill leachate treatment.the coupling process and single process comparison experiments show that the coupling process has better degradation performance for landfill leachate.The single electrochemical process has low efficiency of simultaneous removal.The removal rate of total phosphorus by electrochemical oxidation method is less than 40%,the removal rate of ammonia by nitrogen is only 39%,and the removal rate of cod and ammonia nitrogen by electroflocculation is low,The coupling process has higher simultaneous removal efficiency for contaminants,and the removal rates of cod ammonia nitrogen and total phosphorus are both over 80%The analysis results of various process energy consumption and current efficiency show that the coupling process has the highest current efficiency while ensuring relatively low energy consumptionThe effects of operating factors?nitial pH,current density,chloride ion concentration and dilution factor?on the removal efficiency of pollutants in leachate showed that the removal efliciency of COD under acidic conditions is much greater than that of alkaline conditions,Phosphorus is removed,but the ammonia nitrogen removal effect is much higher than the acidic environment:the contaminant can have a higher simultaneous removal efficiency at an initial pH of 8.44?unadjusted pH?.The contaminant removal rate increases as the current density increases.The chloride ion concentration has little effect on the removal rate of contaminants.As the dilution ratio increases,the contaminant removal rate increases significantly.Under the optimal reaction conditions of initial pH 8.44?unadjusted initial pH?current density of100mA·cm^-2 chloride ion concentation of 10000 mg·L^-1 coupling process for undiluted landfill leachate stock solution The COD removal rate reached 94.23%.the total phosphorus removal rate reached 97.1%,and the ammonia nitrogen removal rate was as high as 98.89%In terms of energy efficiency,when the initial pH is acidic,it helps to reduce the energy consumption of the reaction and improve the current efficiency.As the current density increases,the energy consumption of the reaction increases rapidly,the current efficiency is also greatly reduced;the chlorine in the leachate is increased.The ion concentration can significantly reduce the energy consumption of the reaction while increasing current efficiency Three-dimensional fluorescence spectroscopy analysis of the influent and water showed that the aromatic protein andfulvic acid were first removed during the reaction,and then the COD removal rate was increased mainly by the degradation of humic acid.The results of the comparative experiments show that the total phosphorus in the landfill leachate is mainly removed by the flocculation caused by the neutral electrode.The strong oxidizing hypochlorite generated by the anodic chlorine evolution plays an important role in the oxidation removal of ammonia nitrogen.The Fenton effect produced by the coupling of the cathode and the neutral electrode plays a major role in the removal of COD.The innovation of this experiment lies in the synergy of electroflocculation and electrochemical oxidation,coupling the action of electric Fenton.The reaction mechanism of this experiment is that the by-products generated between the electrodes are effectively utilized.For example,the O₂ generated by the anode is partially dissolved in water,the cathode of the activated carbon fiber adsorbs oxygen molecules and generates H₂O₂,and the neutral electrode The resulting Fe²⁺forms a Fenton effect.At the same time,under the synergistic cffects of electroflocculation,clectrochemical oxidation and air flotation,the pollutants in the leachate are removed synchronously and efficiently.