In a wastewater treatment plant, which tank is most likely to experience primary sedimentation?

The clarifier is the correct answer because it serves a critical function in the primary sedimentation process within wastewater treatment. In this phase, solids in the wastewater will settle to the bottom of the clarifier due to gravity, allowing for the separation of solids from the liquid. This process is essential for removing settleable solids from the influent before going through secondary treatment processes.

The aeration tank, while important for biological treatment, focuses on mixing wastewater with air to promote the growth of microorganisms that degrade organic matter. It does not primarily facilitate sedimentation.

The digester is responsible for the stabilization of sludge through anaerobic digestion, breaking down organic matter further but not for initial sedimentation.

The influent pump station is involved in transporting wastewater to the treatment facility and does not participate in the sedimentation process.

In summary, the clarifier is specifically designed for primary sedimentation, making it the most likely tank to experience this process in a wastewater treatment plant.