Vidyalelo
Civil Engineering · Q151

Waste Water Engineering

Engineering and GATE · Civil Engineering · question 151

Q151

In a sludge tank, the gas mainly produced, is

A.
Oxygen
B.
Nitrogen
C.
Hydrogen
D.
Carbon dioxide
Answer

Answer: Option D

Solution

Answer: Option D
Solution:
In a sludge tank, the decomposition of organic matter takes place under anaerobic conditions. During this process, microorganisms break down organic solids and produce gases as by-products.

The main gases generated are methane (CH₄) and carbon dioxide (CO₂). Since methane is not included in the given options, carbon dioxide is the correct answer.

Oxygen and nitrogen are not produced during anaerobic digestion, and hydrogen is formed only in very small quantities compared to carbon dioxide.