Combined Pre-Treatment of Coagulation-Ozonation for Saline-Stabilized Landfill Leachates

摘要

Coagulated stabilized leachates were ozonated under a continuous regimen at the laboratory scale.Experimental results showed that the coagulation pretreatment allows the removal of complex organic matter related to color in stabilized landfill leachates.Infrared analysis of coagulated organic matter sludges suggests that more than 90 of leachate color is due mainly to the presence of humic acids.These acids are taken from the colloidal particles (0.34-1.0 mu m) contained in landfill leachate.The effect of ozone on residual color removal displays a fast kinetic reaction.The ozone absorption process is associated to reactions with easily oxidizable organic compounds,such as those related to color in stabilized landfill leachates.The experimental results of ozone mass transfer revealed that ozone absorption depends on gas velocity and is substantially favored by chemical reaction.The estimated k'_La values (2-7 s~(-1)) had the same order of magnitude as those reported in treated wastewater.The enhancement factor (E) was estimated to be in the range 3 to 11.