Which part of a wastewater treatment plant is designed for sedimentation of solids?

The clarifier is specifically designed for the sedimentation of solids in a wastewater treatment plant. In this process, the wastewater flows into the clarifier, where the velocity is decreased, allowing suspended solids to settle to the bottom under the influence of gravity. This settling creates a sludge layer at the bottom, while the clearer liquid above is typically known as supernatant or treated effluent.

This sedimentation step is crucial for several reasons. It helps to separate solid materials from the liquid, which aids in further treatment processes and ensures that contaminants are removed efficiently. The solids collected are often returned to earlier stages of treatment or processed further for disposal. By optimizing the sedimentation process, clarifiers contribute significantly to the overall efficiency of wastewater treatment, improving the final effluent quality.

In contrast, the other options serve different functions: a grit chamber is designed to remove coarse solids and grit before entering the main treatment processes; an aeration tank is used for biological treatment, where microorganisms break down organic matter; and a chlorinator is used to disinfect the treated wastewater before it is discharged or reused.