Select the correct statement from th following.

Options

A. Activated sludge in settlement tanks of sewage treatment plant is a rich source of aerobic bacteria
B. Biogas is produced by the activity of aerobic bacteria on naimal waste (dung)
C. Methanobacterium is an aerobic bacterium found in rumen of cattle
D. Biogas, commonly called gobar gas, is pure methane.

Answer

A

Explanation

` *` Biogas is produced by the activity of anaerobic bacteria on animal waste (dung).
`*` Methanobacterium is an anaerobic bacterium found in rumen of cattle.
`*` Biogas, commonly called gobar gas, is mainly methane (about 70%).