A baffle is best described as:

• A. A container
• B. A chemical additive
• C. A board used to direct flow, uniform velocities, absorb energy, divert, guide, or agitate liquids
• D. A measurement device

Answer: (C)

A baffle is a barrier placed inside a tank or channel to shape how liquid moves. By acting as a board or plate, it directs flow, helps create more uniform velocities, absorbs or dissipates energy to damp turbulence, and can divert, guide, or even promote agitation where needed. This makes the flow path longer and more controlled, improving processes like settling, mixing, or contact with other treatment steps while preventing short-circuiting from inlet to outlet.

It isn’t a container, since it isn’t used to hold liquids. It isn’t a chemical additive, because it’s not a substance added to the water. It isn’t a measurement device, because its role is physical flow control inside the tank.