Circular clarifiers require a 'skirt' or ___ ___ around the influent discharge point, to minimize hydraulic short-circuiting.

• A. Baffled inlet
• B. Inlet screen
• C. Diffuser ring
• D. Skirted inlet

Answer: (A)

In circular clarifiers, controlling how the incoming flow enters the basin is crucial to prevent hydraulic short-circuiting—where the water finds a fast path to the outlet without spending enough time in the clarifier. A baffled inlet uses flow-directing baffles at the influent discharge to slow down and spread the water, directing it around the perimeter rather than letting it shoot straight across. This creates a more uniform, circular flow pattern and gives suspended solids more time to settle before reaching the effluent.

That’s why the term used here is baffled inlet. It specifically describes the flow-control feature that reduces short-circuiting. An inlet screen mainly blocks debris, not distribution; a diffuser ring is associated with diffusing air or flow in aeration systems; and while a skirted inlet describes a physical skirt, the term that best captures the flow-control function needed to minimize short-circuiting is baffled inlet.