Question

A tank is converted to treat organic waste water from kitchen as shown in the figure below. Biogas gets accumulated on top part of the tank. Which of the following options is a suitable location for drilling an air hole to maintain the water level inside the tank? 

• A. A
• B. B
• C. C
• D. D

Hint:

Air holes should always be positioned at the highest point in closed systems to allow the escape of gases.

Answer 1

The Correct Option is C

Step 1: Analyze the function of the air hole.
- An air hole is needed to release accumulated biogas, which otherwise creates pressure and prevents the proper functioning of the system.
Step 2: Determine the correct location for drilling.
- The highest point of the tank is ideal for drilling the air hole since biogas collects at the top. This ensures smooth removal of gas and maintains the water level.
Step 3: Conclude the answer.
The suitable location for the air hole is:\[ {\text{C - At the highest point of the tank}}. \]