California Wastewater Treatment Operator Practice Exam

Which of the following is true about the extended aeration process?

1. It produces more waste sludge than other processes

2. It does not produce any waste sludge

3. It only works with industrial wastewater

4. It does not produce as much waste sludge as other processes

The correct answer is: It does not produce as much waste sludge as other processes

The extended aeration process is a type of activated sludge treatment that is designed for efficient stabilization of organic matter while promoting significant biological activity over an extended period. One of its notable characteristics is the reduced production of waste sludge compared to other treatment processes. This is primarily because the process allows for the complete degradation of organic materials and maximizes the growth of microorganisms that are responsible for the treatment of the wastewater. As a result, a higher percentage of the influent organic matter is converted into biomass rather than being wasted, leading to less sludge being generated. Therefore, stating that it does not produce as much waste sludge as other processes is accurate. The other options suggest various misconceptions. The option indicating that it produces more waste sludge contradicts the process's operational advantages. The claim that it does not produce any waste sludge is incorrect, as some sludge is still generated, just in lesser quantities. Finally, stating that it only works with industrial wastewater is misleading, as the process is applicable to both municipal and industrial wastewater treatment.