Final answer:
The secondary clarifier receives flow from the secondary aeration tank and is crucial for separating solids from liquids in wastewater treatment.
Step-by-step explanation:
The secondary clarifier receives flow from the secondary aeration tank and is used to separate the solids from the liquid. In the secondary treatment stage of wastewater treatment, microorganisms are used to decompose organic material and absorb nutrients. In a secondary clarifier, these microorganisms and remaining solids settle out of the effluent as activated sludge, which is then processed further or recirculated back into the system to improve the breakdown of organic matter.
In contrast, initial solid separation occurs in the primary treatment at the sedimentation tank, also called the primary clarifier, where sludge are removed. Secondary treatment focuses on biological matter removal, often through microbial action in the presence of oxygen. Finally, in some cases, tertiary treatment offers an additional cleaning phase, sometimes necessary when the effluent is discharged into sensitive ecosystems.