In which type of tank do heavier solids settle during the treatment process?

The clarifier is specifically designed to facilitate the settling of heavier solids during the wastewater treatment process. In a clarifier, wastewater enters and is allowed to sit for a period, giving heavier particles, such as grit, sand, and other solids, time to settle to the bottom of the tank due to gravity. The settled solids accumulate as sludge, which can then be removed for further treatment or disposal.

The role of the clarifier is crucial in separating solids from the liquid phase, making it a key component in both primary and secondary treatment processes. The design of the clarifier promotes this settling by providing a large surface area for solids to settle and ensures that the flow conditions allow for effective separation.

Other types of equipment mentioned, such as screeners, grinders, and filters, serve different purposes. Screeners are used to remove large debris, grinders are designed to shred solids to prevent clogging and improve downstream processes, and filters are intended for the removal of smaller particles after initial treatment stages. These functions do not involve the settling of heavier solids as effectively as a clarifier.