Class 12th Biology 2016 Set2 Delhi Board Paper Solution
Question 9
List the events that lead to biogas production from waste water whose BOD has been reduced significantly.
Answer
After significant reduction of BOD, the effluent is passed into a settling tank where the floes are allowed to sediment to form activated sludge. This sludge is pumped into anaerobic sludge digesters where anaerobic bacteria digest the microbes of the sludge to release a mixture of gases such as methane, H2S and CO2. These gases form biogas which can be used as a source of energy.
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