Wastewater Treatment Operator Certification Practice Test

What operational change is typically made during colder winter months in wastewater treatment?

1. Decrease solids under aeration to provide fewer microorganisms

2. Increase solids under aeration to provide more microorganisms

3. Increase temperature in the aeration tank

4. Decrease aeration time

The correct answer is: Increase solids under aeration to provide more microorganisms

In colder winter months, wastewater treatment plants often experience a decrease in microbial activity due to lower temperatures. To compensate for this natural reduction in microbial efficiency, operators typically increase the amount of solids under aeration. By increasing solids, which contain the microorganisms responsible for breaking down organic matter, the treatment efficiency can be maintained despite the reduced metabolic rates caused by the colder environment. This approach ensures that there are still enough microorganisms available to effectively process the incoming wastewater. An increase in solids strengthens the biological treatment processes, allowing for improved degradation of organic material and stable overall system performance. Effectively managing the microbial population and ensuring adequate treatment even in cold weather conditions is crucial for maintaining compliance with effluent quality standards. Adjustments like increasing solids under aeration are key operational strategies to adapt to seasonal changes in wastewater treatment processes.