Investigation of the Impact of Landfill Age and Climate Factors on Landfill Leachate Characteristics

Landfill leachate data compiled from different landfills from 46 countries around the world was analysed by multivariate statistical approach. PCA was conducted to classify leachate data into groups for the assessment of main properties and ANOVA was used to find out variations between the leachate parameters according to the age of the landfill and climate factors. PCA results showed that the first component having high concentration of inorganic parameters came from aged landfills whereas the second component having high concentration of organics and divalent ions came from younger sites. It was statistically proven that precipitation is the most important factor governing the leachate quality and landfill age plays an important role especially for the organic strength. ANOVA results showed that inorganic content of leachate does not change significantly with time as organics do. Regarding climate effect, only some leachate parameters including mainly organics and BOD/COD ratio were found significantly higher in landfills located in low precipitation areas than the ones in high rainfall climates.