Question

Sewage treatment promises the production of biogas that could be used as a source of energy for various purpose. Indian villages have adopted the Biogas generation at a small scale using Cow dung as the raw material for production of Biogas.
How does sewage treatment help in biogas production?

• A. The flocs acting on the effluent produces biogas.
• B. The flocs are active microbes. Once the nutrients are gone, they die and decay, which produces biogas.
• C. The secondary sludge left behind after the flocs act on nutrients, produces biogas when acted upon by anaerobic bacteria.
• D. None of the above.

Answer 1

The correct option is C The secondary sludge left behind after the flocs act on nutrients, produces biogas when acted upon by anaerobic bacteria.

The secondary sludge is left behind once the floc acts on the nutrients in the effluent. This sludge cannot be dumped into water bodies. Therefore it is channeled into a chamber where the anaerobic bacteria decompose them further and produce biogas. In this way sewage treatment plants can be used to produce biogas as well.