Florida Wastewater Practice Test

Where does the effluent from an aerator typically go next?

1. Primary clarifier

2. Secondary clarifier

3. Final effluent discharge

4. Activated sludge tank

The correct answer is: Secondary clarifier

The effluent from an aerator typically goes to the secondary clarifier. In the treatment process, aeration involves introducing air into wastewater to support the growth of microorganisms that break down organic matter. After this stage, the aerated mixed liquor is directed to the secondary clarifier, where the heavier solids, including the biomass (activated sludge), settle out of the water. This step is crucial, as it allows for the separation of treated wastewater from the solids. The clarified water can then proceed to further treatment or discharge, while the settled sludge can be returned to the aeration tank or removed for further processing. In contrast, the primary clarifier is used earlier in the treatment process to allow for the settling of larger solids before aeration occurs. The final effluent discharge refers to the treated water after multiple stages of purification, which occurs after secondary clarification. The activated sludge tank is another term for a tank where aeration takes place and is not where the effluent goes directly after the aerator.