California Wastewater Treatment Operator Practice Exam

Which of the following will not cause short circuiting in a clarifier?

1. an uneven flow distribution

2. blockage in the feed pipe

3. flow line of launder is low

4. improper baffle design

The correct answer is: flow line of launder is low

The flow line of the launder being low is not a factor that contributes to short-circuiting in a clarifier. Short-circuiting occurs when water moves rapidly through a treatment unit, bypassing a significant portion of the tank. A low launder line might actually assist in capturing solids that settle at the bottom, ensuring that the treated water flows properly through the outlet without causing turbulence or rapid movement that would undermine the clarification process. On the other hand, uneven flow distribution can lead to areas in the clarifier that do not receive adequate treatment time. Blockages in the feed pipe restrict flow and may create uneven water levels, directly contributing to short-circuiting as water backs up and flows rapidly to the outlet. Moreover, improper baffle design can disrupt the intended flow patterns, allowing water to flow too quickly through the tank, which directly supports the occurrence of short-circuiting. Each of these factors plays a significant role in the efficiency and effectiveness of the clarification process.