Basic Wastewater Operator Practice Exam

What is the primary advantage of using activated sludge in wastewater treatment?

1. Reduces the volume of sludge produced

2. Increases the rate of organic removal

3. Improves nutrient removal efficiency

4. Decreases operational costs

The correct answer is: Increases the rate of organic removal

The primary advantage of using activated sludge in wastewater treatment is that it increases the rate of organic removal. This process involves the use of microorganisms in a mixed liquor to break down organic pollutants present in wastewater. The activated sludge process enhances the biological treatment of wastewater by promoting the growth of biomass that effectively decomposes organic material. By maintaining optimal conditions for microbial activity, such as aeration and mixing, the system can rapidly assimilate organic matter, leading to more efficient treatment and lower concentrations of contaminants in the effluent. Each of the other options presents benefits that are not as directly associated with the primary function of the activated sludge process. While reduced sludge production, improved nutrient removal, and decreased operational costs can be desirable outcomes in certain contexts, the main emphasis of the activated sludge process is its capability to significantly accelerate the rate at which organics are removed from wastewater. This mechanism is foundational to achieving compliance with regulatory standards for effluent quality and protecting public health and the environment.