Study On Treatment Of Concentrated Water From Nanofiltration Of Landfill Leachate By Three-dimensional Electrode Method

Landfill leachate is a kind of high concentration organic wastewater produced in the process of sanitary landfill.Its composition is complex and harmful.It can be discharged into the environment or municipal sewage network only after it reaches the treatment standard.With the increasingly strict national environmental protection policies and emission standards,most landfills in China use membrane method for advanced treatment of landfill leachate.How to properly dispose of the concentrated water produced in the membrane separation process has become a technical problem in engineering application.Three-dimensional electrocatalytic oxidation technology has been applied to the treatment of various organic wastewater.However,the current research on the concentrated water from nanofiltration of landfill leachate is rarely reported in the literature.This paper studies the treatment of concentrated water from nanofiltration by three-dimensional electrocatalytic oxidation technology.A new three-dimensional electrode system was constructed by designing reactor,selecting anode materials and particle electrodes,and the operation parameters were optimized.On this basis,the combined process was studied in order to treat the concentrated water from nanofiltration economically and efficiently,and to provide technical support for the actual process design.The main conclusions are as follows:?1?In the two-dimensional electrode system:when Ti/RuO₂-IrO₂,Ti/IrO₂-TaO₂,Ti/Pt and Ti/PbO₂ electrode are used as anodes to treat concentrated water,the electrochemical performance of Ti/PbO₂ electrode is the best,and the removal efficiency of chroma,COD and NH3-N in concentrated water is the best.?2?In the three-dimensional electrode system:Ti/PbO₂ electrode was used as anode,stainless steel as cathode and Sn-Sb loaded activated carbon as particle electrode.When initial pH=5,cell voltage 10V,the amount of aeration is 20L/min,the amount of particle electrode filling is 37.5g/L,COD removal rate can reach 68.76%after 2 hours of electrolysis.?3?The coagulation-three-dimensional electrocatalytic oxidation-biological activated carbon combined process was established to treat concentrated water.When the coagulant dosage was 1500 mg/L and the three-dimensional electrolysis time was 2hours,the effluent chroma,COD and NH3-N meet the table 2 standard of"Pollution Control Standard for Domestic Waste Landfill Site"?GB16889-2008?,and the direct operation cost was about 42.63 yuan/m³.