gas and leachate
Leachate and landfill gas
comprise the major hazards associated with a landfill. While leachate may
contaminate the surrounding land and water, landfill gas can be toxic and lead
to global warming and explosion
leading to human catastrophe (Phelps,
1995). (Note that global warming, also
known as greenhouse effect, refers
to the warming
of the earth's atmosphere by the
accumulation of gases (e.g., methane, carbon dioxide and chlorofluorocarbons)
that absorbs reflected solar radiation.
of waste: The deposition of waste containing biodegradable matter
invariably leads to the production of gas and leachate, and the amount depends
on the content of biodegradable material in the waste.
content: Most micro-organisms
require a minimum of approximately 12% (by weight)
moisture for growth, and
thus the moisture content of landfill
waste is an important factor in determining the amount
and extent of leachate and gas production.
methanogenic bacteria within a landfill produce methane gas, which will grow
only at low pH range around neutrality.
Particle size and density: The size
of waste particle affects the density
that can be achieved upon compaction
and affects the surface
area and hence volume. Both
affect moisture absorption and therefore are potential for biological
increase in temperature tends to increase gas production. The temperature
affects the microbial activity to the extent that it is possible to segregate
bacteria, according to their optimum temperature operating conditions.