Tennessee Wastewater Operator Practice Exam

During extreme cold weather, what action is recommended to reduce heat loss from a trickling filter?

1. Increase air inlets by 10-20%

2. Close 25-50% of air inlets

3. Insulate the entire filter structure

4. Utilize heating elements around the filter

The correct answer is: Close 25-50% of air inlets

In cold weather, the primary concern for a trickling filter is to maintain optimal operational conditions while minimizing heat loss. Closing 25-50% of air inlets helps reduce the amount of cold air entering the system, which can lower heat loss and maintain warmer temperatures within the filter. By reducing the airflow, the system can retain more heat generated from biological processes, which is crucial for maintaining the desired microbial activity essential for effective wastewater treatment. If air inlets remain fully open, cold air could significantly impact the temperature within the filter, potentially slowing down or inhibiting the necessary biological processes. Additionally, this method is a practical solution that directly addresses the challenges posed by extreme cold without necessitating significant infrastructure changes or energy consumption associated with options like heating elements or extensive insulation. Closing the air inlets, while still allowing for some minimal ventilation, strikes a balance between preventing heat loss and ensuring some level of aeration necessary for the microbial population to thrive.