Study On Pretreatment Of Landfill Leachate With Map-Fenton

Landfill leachate is a kind of complex waste water which come from the process oflandfills.It contains high-organic-polluting and complex waste water which if from theprocess of landfills.There is a high concentration of ammonia nitrogen,organic matter andheavy metal pollutants.If handled properly,it will be harmful to environment.With thepromulgation of new 《Life Landfill Pollution Control Standards》in2008,treatment oflandfill leachate has became necessary to every landfill sites. But it is difficult to meet therequirement of emission standard only by biological method.It usually need to carry on thepretreatment and the depth of the subsequent handling.Magnesium ammonium phosphateprecipitation method and Fenton method are adopted in this project for leachatepretreatment.We carries on the experimental study for each stage respectively,to optimize thevarious factors that influence the treatment.They were determined that the size of the influenceof the factors to each method and the optimum experimental conditions.With ammonianitrogen and COD removal rate as index.The experimental results show that the optimumcondition combination of garbage leachate by MAP phase processing ispH=9.5,n(Mg2+)∶n(NH4+)∶n(PO43-)=1.3∶1.0∶1.3,the reaction time is25min,and theorder of the impact of various factors on MAP precipitation is:pH＞n(Mg2+)∶n(NH4+)＞reaction time＞n(NH4+)∶n(PO43-).The best condition of Fenton reaction stage is thatpH=3.5,H2O2=20ml/L,n（H2O2）∶n（Fe2+）=5∶1,thereactiontimeis2.0h,andthe orderof the impact of various factors on Fenton oxidation is:pH＞H2O2＞n(H2O2)∶n(Fe2+)＞reaction time. After the joint process pretreatment of leachate,the average removal rate ofammonia nitrogen and COD can reach93.89%and90.12%.