Leachate is the liquid percolated through the waste layers within a landfill cell. It contains high level
of organic pollutants in the form of high COD, TOC while dissolving various heavy metal elements [5].
The leachate generation is highly dependent on soil types, waste composition, degree of compaction of
the waste disposed, amount of landfill received, evapotranspiration and also type of landfill and the age of
landfill [6]. Leachate generation begins as soon as the disposal site receives its first batch of waste, where
the liquid sourced from the moisture that exists in the waste, water from degradation of putrescible waste
and rain. This will continue until the disposal sites cease its operation and no longer receive additional
waste. At this instant, leachate will be produced mainly from the degradation of the waste within the
waste cells. Due to this factor, characteristics of leachate will vary from time to time. Normally, the
concentration will be the highest during the first 3-8 years when biodegradation is occurring very rapidly
[6]. Table 1 depicts the characteristics of landfill leachate samples obtained landfills in Malaysia