Question

What is the nutrient composition and use of the spent slurry obtained from the outlet tank of a biogas plant?

Options

• It must be treated chemically before any application

• It is toxic waste that must be disposed of safely

• It is nutrient-rich organic fertilizer suitable for agricultural use

• It contains only inert materials with no agricultural value

Answer 1

The spent slurry removed from the outlet tank is enriched with nutrients and serves as a nutrient-rich organic fertilizer. This dual benefit of biogas production - generating energy while producing valuable manure - makes biogas plants economically attractive. The slurry contains nitrogen, phosphorus, and potassium along with organic matter, making it excellent for soil enrichment and crop production.