Study On Three-dimensional Electrocatalytic Treatment Of Leachate In Village Garbage Transfer Station

The water quality of leachate from village garbage transfer station is quite different from that of landfill leachate.At present,the treatment process of landfill leachate is“A²O+NF+RO”,but the amount of leachate from village garbage transfer station is small and dispersed,and the concentration of organic pollutants is high,which requires small scale and high standard of village landfill leachate treatment facilities,but the corresponding investment cost will also be increased.However,the initial investment and operation management cost of nanofiltration+reverse osmosis process is high,and there are still some problems,such as membrane blockage and secondary pollution of concentrated liquid,so it is not suitable for leachate treatment in village and town garbage transfer stations.On the other hand,three-dimensional electrocatalysis has the characteristics of high treatment efficiency,compact device structure and high degree of automation,which is easy to make into mobile equipment and shared by multiple sites,which is very suitable for the application scene of garbage transfer stations in villages and towns.Therefore,this study starts from the water quality characteristics of leachate from different sites,studies the degradation effect of leachate,constructs a three-dimensional electrocatalytic system,and discusses the influence of different factors on the treatment effect,so as to select the best conditions.Finally,with the combination of three-dimensional electrocatalysis and biological treatment,different combinations can be applied to a variety of scenes.（1）Compared with the landfill leachate,the leachate of the village garbage transfer station has lower p H,higher COD concentration,lower NH₃-N concentration and higher TP content,which was identified as to high concentration organic wastewater.The amount of main metal substances in the leachate of iron,manganese and zinc,heavy metals,humic acid and fulvic acid in the leachate were low,mainly contained tryptophan and tyrosine proteins and soluble microbial by-products.（2）The characterization results of electrochemical performance show that the oxygen evolution potential of Si/BDD electrode is the highest in all kinds of media,which is a kind of catalytic electrode with high oxygen superpotential,and the chlorine evolution potential of Si/BDD is lower than that of oxygen evolution potential,which can give priority to chlorine evolution reaction.In this study,three-dimensional electrocatalysis was used to study the degradation effect of leachate.The results show that Si/BDD has the strongest ability to remove pollutants and relatively low energy consumption;the addition of Sn O₂Sb O₃/GAC particle electrode can improve the pollutant removal ability,and the performance of reuse is better.（3）In this study,the effect of process parameters on the degradation of leachate by three-dimensional electrocatalysis was studied,and the optimum process parameters were determined as follows:not adjusting leachate p H,current density 30 m A/cm²,particle electrode filling degree 50%,plate spacing 10mm,adding 0.01 mol/L Na₂SO₄ electrolyte.Under these conditions,after 4 hours of reaction,the effluent COD and NH₃-N can meet the"Municipal solid waste Landfill pollution Control Standard"（GB16889-2008）Table 2 standard,at this time the energy consumption is 73.8 k Wh/kg COD,the current efficiency is 40.8%,and the power consumption is about 180 k Wh/m³.（4）Combining three-dimensional electrocatalysis with biological treatment process,according to different application scenarios,three kinds of process routes up to the standard are designed,respectively:（1）only using three-dimensional electrocatalysis,COD and NH₃-N can meet the emission standard after 4 hours of reaction,and the main operation cost is 180.25RMB/m³,（2）when“three-dimensional electrocatalysis（30 m A/cm²）3 h+biological treatment”,the main operation cost is 135.25 RMB/m³.（3）“three-dimensional electrocatalysis（30 m A/cm²）0.5 h+biological treatment+three-dimensional electrocatalysis（15m A/cm²）4h”,energy consumption is relatively low.The main operating cost is about 87.75 RMB/m³.