Which one of the following gases is released mostly from landfills in urban areas?
A
Nitrogen
B
Hydrogen
C
Methane
D
Oxygen
Correct Answer: Methane
Decomposing waste in the landfills, by the action of microorganisms, produce methane and carbon dioxide. Landfill gas consists of 40-60% of methane and rest is carbon dioxide. Trace amount of volatile organic compounds (<1) are also present which mainly comprise of hydrocarbons.