Tennessee Wastewater Operator Practice Exam

What is the purpose of a feed well in a primary clarifier?

1. Increase sedimentation

2. Prevent short circuiting

3. Enhance biological activity

4. Reduce chemical usage

The correct answer is: Prevent short circuiting

The purpose of a feed well in a primary clarifier is to prevent short circuiting. In wastewater treatment, a feed well is designed to ensure that the influent wastewater enters the clarifier in a controlled manner, allowing for uniform flow distribution. By doing this, the feed well helps to maintain a consistent flow of wastewater across the entire surface area of the clarifier. This ensures that all parts of the clarifier receive an adequate amount of wastewater, allowing for effective sedimentation of solids. Short circuiting occurs when a portion of the influent bypasses the treatment process, resulting in ineffective removal of solids and poor overall performance of the clarifier. The feed well mitigates this risk, promoting optimal settling conditions and improving the efficiency of the primary clarifier. The other options, while relevant to wastewater treatment, do not directly address the key function of the feed well in this context.