Study On Combined Treatment Process Of Landfill Leachate Membrane Filtration Concentrate

For the purpose of meeting the discharge standard of landfill leachate,the Membrane treatment process has to be popularized in the landfill leachate treatment industry.But the Membrane filtration concentrate is difficult to be effectively treated,which is the main reason hindering the application and development of the process.So it is necessary to develop a set of feasible solution.This project aims at the reverse osmosis（RO）Membrane filtration concentrate from a waste incineration power plant in Chongqing,using electroflocculation,electro-fenton,anoxic and oxic sequencing batch activated sludge process（A/O type SBR）and electrochemical oxidation combined process for experiments.The best experimental conditions for electroflocculation are:the initial p H of the Membrane filtration concentrate is 3.0,the electrolysis reaction time is 1 h,the current intensity is 1.5 A,and the removal rate of effluent Chemical oxygen demand（COD）is38.3%.The best experimental conditions for electro-fenton are:stirring time is 1.5 h,the addition amount of H₂O₂ is 2.0%,and the theoretical H₂O₂addition amount is determined according to the COD and water amount of the experimental water,according to n（H₂O₂）:n(Fe²⁺)=3:1,for electrolytic iron dissolution.The initial p H of electroflocculation effluent is 3.0,and H₂O₂ is added in two ways in batches,the effluent COD is 1078 mg/L,and the removal rate is 57.7%.The A/O type SBR experiemnt uses electro-fenton effluent to acclimate activated sludge.The treatment effects of different operation modes of SBR are compared.The effect of the amount of Cationic polyacrylamide（CPAM）addition on sludge sedimentation was investigated.The effluent COD removal rate is 72.2%to 80.0%,the NH₃-N removal rate is 99.2%to 99.5%,and the TN removal rate is 98.6%.The best experimental conditions for electrochemical oxidation experiment are:the current intensity is 25 A and the electrolysis time is 1 h.In parallel experiments,the average removal rate of effluent COD is 60.2%,the average removal rate of total organic carbon（TOC）is 58.0%,the removal rate of TN is 42.4%,the removal rate of NH₃-N is100%,and the chroma removal rate is 75.0%.The Biological oxygen demand（BOD₅）of the Membrane filtration concentrate raw water and the electro-fenton effluent was detected.The results showed that the BOD₅/COD of the electro-fenton effluent was increased from 0.08 to 0.33.UV-visible absorption spectra were obtained for the effluent from difference processes analysis to verify that the combined process could effectively improve the Biodegradability of the Membrane filtration concentrate.