Question

Observe the figure and write the answers to the questions asked.

1. Name the above figure.
2. What is it used for?
3. Which gas is formed in it?
4. How is this gas formed?
5. What is done with sewage?

Answer 1

1. The given figure represents the Modern landfill site
2. It is used for disposal of degradable waste in urban areas.
3. Methane gas is formed in landfill pits.
4. Microbes present in the soil decompose the waste resulting in the formation of methane gas.
5. i. In villages, domestic sewage is disposed of either in nearby soil or in biogas plants, whereas in cities, sewage is carried to a processing unit and acted upon by microbial processes.
   ii. This sewage is acted upon by microbes that destroy the pathogens and decompose carbon and xenobiotic compounds in the sewage.
   iii. The sludge that settles down in the process can be then used as fertilizer while the water released after microbial treatment is environmentally safe.