The residue left after methane production from cattle dung is

Options

A. burnt
B. burried in land fills
C. used as manure
D. used in civil construction

Answer

C

Explanation

Biogas is a methane rich fuel gas produced by anaerobic breakdown or digestion of biomass with the help of methanogenic bacteria. Biogas is made up of methane `(50 - 70%)`, carbon dioxide `(30-40%)` with traces fo nitrogen, hydrogen sulphide and hydrogen. the effluent and residue left after the fermentative generation of biogas is rich in minerals, lignin and a part of cellulose. it is an ideal manure.