Question

The gases produced by landfills primarily comprised of:-
1. Ethane and oxygen
2. Sulphur dioxide and nitrogendioxide
3. Methane and carbondioxide
4. Carbon monoxide and hydrogen sulphide

Answer 1

Correct Answer - Option 3 : Methane and carbondioxide

Explanation:

Sanitary landfills:

• This is a method of disposal of municipal solid waste.
• In this method disposal of refuse is being carried out over the low lying area in the layers of approximately 1.5 m thick.
• Each layer after being disposed of is properly compacted and left for at least 7 days before the application of another layer over it.
• This entire process is biological in approach in which decomposition of the organic matter takes place in 3 phases (action by aerobic micro-organisms, action by acid former, action by methane former)
• For optimum decomposition moisture content of the refuse must be greater than 60%.
• This entire process completed within 2-12 months after which the height of the landfill is reduced by 25-40%.
• The only drawback associated with this method is the formation of end products (Carbon-dioxide and methane).
• In order to channelize the flow of the fluids around the fill area sealants maybe apply over the cells.