Modeling Of Gas Pollution From Ilorin Animal Waste Dumpsite

CHAPTER TWO
LITERATURE REVIEW
2.1 CARBON DIOXIDE EMISSIONS
Carbon dioxide (CO2) emissions occurring result from the decomposition of animal wastes in the presence of a sufficient supply of air to ensure aerobic conditions. Under aerobic conditions naturally occurring bacteria utilize the oxygen in air to oxidize the biodegradable carbon in the animal waste to carbon dioxide
Aerobic conditions occur when animal wastes are:
I.    Treated in an oxidation pond or on aerated lagoon
II.    Composted with sufficient turning and aeration of the compost heap
III.    Spread thinly enough onto land to allow aerobic soil condition to be maintained
Carbon dioxide emissions should not lead to any net change to be global greenhouse gas balance because all of the carbon oxidized to carbon dioxide is likely to have been ingested by the animals as food (grass, grain etc), which will have absorbed carbon dioxide from the during their growing cycle via photosynthesis.
2.2   METHANE EMISSION
When organic carbon, as contained in animal, decomposes without sufficient air to oxidize the carbon to carbon dioxide the biodegradable carbon is organic strength of animal waste and because the waste has been produced under anaerobic (i.e. in the absence of air) conditions within the digestive system of the animal, animal wastes are inherently anaerobic and be expected to generate methane unless they are managed in such a way as to aerate them. Even manure deposited on the ground (such as ‘cowpats’) is anaerobic inside and emissions of methane are produced as lies on the ground.
Because methane has a global warming potential that is 21 times greater than carbon dioxide, emissions of methane can result in increased global warming rather than maintaining the carbon cycle as would happen if the carbon was fully oxidized to carbon dioxide. Consequently, a reduction of methane emissions from animal waste or conversion of the methane to carbon dioxide is necessary to ensure that the carbon cycle is maintained.
Anaerobic conditions develop and biogas is generated:
I.    In ponds or basins where animal manure is collected and/or stored
II.    Where collected animal manures are  spread too thickly on land
III.    From animal manures deposited in the field such as ‘cowpats’
IV.    Where animal manure is collected in
2.3 NITROUS OXIDE EMISSIONS
Nitrous oxide (N2O) is potent greenhouse gas because of its high global warming potentials. It can be a significant emission from animal waste under certain conditions, particularly when animal manures are applied to soil.
2.4 NON POINT POLLUTIO
The most significant threat to water resource across the U.S now comes from non point source pollution- which does not come out of the end pipe. As effort to reduce water pollution from factory and sewage treatment plant has succeed, attention is now turning to the largest contributor to non point pollution: agriculture current farming practices often result in the release of sediment, fertilizer, pesticide and animal wastes to local watersheds. Local impacts have often worsened as smaller family farms have being replaced by cooperate operations housing thousand of animal in assembly-line conditions. These operations have multiplied in recent years, spreading into many states that lack adequate environmental controls. The estimated one billion tons of feces and urine produced each year by livestock, and the way in which it is treated, pose one of America’s serious pollution threats.