Study On Advanced Treatment Of Landfill Leachate By Electrocatalytic Oxidation Coupled With Biochemical Technology

“Waste Besieged City”has become an inevitable major problem in urban management,which will hinder the development and construction of the city.At present,domestic waste in our country is mainly processed through sanitary landfill,and sanitary landfill will inevitably produce landfill leachate,that is,a component produced by the waste during landfilling is complex,difficult to biodegrade,high in pollutant concentration and toxic big organic wastewater.If not handled properly,it will cause serious pollution to the environment around the landfill.Among them,it is more difficult to deal with the discharge of old landfill leachate.To this end,this paper takes the old landfill leachate as the research object,in view of the extremely poor biodegradability and refractory characteristics of the old leachate,a new electrocatalytic oxidation-biochemical A/O coupling process is designed and aimed at this process The operating parameters,processing effects and technical and economic feasibility of the system have been analyzed to lay the foundation for engineering applications.The specific research results are as follows:1.A water quality analysis was conducted on the leachate of the old landfill,and it was found that there are high concentrations of pollutants that are difficult to biodegrade in the old leachate.Different types of organic acids and organic pollutants with complex structures such as naphthenes and aromatic hydrocarbons greatly reduce the biodegradability of leachate.2.The electrocatalytic oxidation unit was used to study the effect of degrading leachate.The results show that the comprehensive effect of DSA anode electrode material is better than Sn,Fe and Ti electrode materials;the main factors affecting the degradation effect of COD,ammonia nitrogen and TOC are current density,initial p H,pole spacing,etc.;current density of 10 m A/cm~2,initial p H=6～7,pole spacing of 2 cm are the best conditions for electrocatalytic oxidation unit to degrade pollutants.3.The treatment of leachate by the electrocatalytic oxidation-biochemical coupling process was studied.The results show that the aged leachate can be discharged directly after electrocatalysis,A/O biochemical,and secondary electrocatalytic treatment,reaching the“Pollution Control Standard for Domestic Waste Landfill”(GB 16889-2008);the front of the electrocatalytic oxidation unit is the key to improving the biodegradability of the aged leachate,and the secondary electrocatalytic treatment is the water pollutant index in the aged leachate guarantee to meet emission standards.4.Through technical and economic analysis of the process,this process has better advantages than the membrane treatment process in the treatment of aging leachate,avoiding membrane pollution,the use of additional agents and the treatment of concentrated liquid,and improving the efficiency of leachate treatment save the cost of process operation.