What function does a clarifier serve in a wastewater treatment facility?

A clarifier plays a crucial role in wastewater treatment by separating solids from liquids during the sedimentation process. As wastewater flows into the clarifier, it undergoes a reduction in velocity which allows heavier solids, such as sludge, to settle at the bottom while the lighter liquid, primarily water, remains at the top. This separation is vital for removing suspended solids from the wastewater, ensuring that it is treated effectively before proceeding to further treatment stages or being discharged. The clarity of the liquid that results is essential for meeting environmental regulations and protecting water quality.

The other functions listed involve processes that are important in different stages of treatment but are not the primary function of a clarifier. Disinfection typically occurs later in the treatment process to eliminate pathogens, aeration is usually carried out in aeration tanks to promote biological treatment, and chemical mixing occurs in preparation for wastewater treatment. Each of these processes is significant but distinct from the role of the clarifier in solid-liquid separation.