California Wastewater Treatment Operator Practice Exam

What is common practice in an activated sludge process?

1. recirculate activated sludge

2. add more chemicals

3. increase temperature

4. dilute the sludge

The correct answer is: recirculate activated sludge

In an activated sludge process, it is common practice to recirculate activated sludge. This helps to maintain a healthy population of microorganisms that are essential for treating wastewater effectively. By recirculating the activated sludge, the microorganisms have more contact time with the incoming wastewater, allowing them to break down organic matter more efficiently. This process helps to ensure proper treatment of the wastewater before it is discharged. Adding more chemicals, increasing temperature, or diluting the sludge are not common practices in the activated sludge process. Adding more chemicals may disrupt the microbial population, increasing temperature can have negative effects on the microorganisms, and diluting the sludge would reduce the efficiency of the treatment process. The correct and common practice is to recirculate activated sludge to maintain an optimal environment for the microorganisms to thrive and treat the wastewater effectively.