Treatment of landfill leachate by three-stage SBR process and mid-oxidation with adsorption

A process of three-stage SBR process in two reactors with mid-oxidation by ozone is used for the treatment of landfill leachate.When COD of landfill leachate is 3 013 mg/L,BOD,1 298 mg/L,NH+4-NR,195 mg/L,TN,272 mg/L,the removal rates of COD,BOD,NH+4-N and TN are 97.3%,97.8%,91.3%,92.1% without the mid-oxidation,when the hydraulic retention times of anaerobic stage,anoxic stage and oxic stage are 24h,3h and 1h,respectively.With 30 mg/L of ozone dosed in the outlet of anaerobic SBR,the total removal of COD,BOD,NH+4-N and TN are 96.7%、97.1%、87.7%、92.8%.20 mg/L of powder activated carbon(PAC)dosed can increase the removal of COD,BOD,NH+4-N and TN to 98.5%、99.3%、94.6%、94.7%,respectively.PAC can remove some organisms in water and decrease the effect of ozone on the following oxic process.