Texas Wastewater Class B Practice Exam

What factor can greatly affect the efficiency of the activated sludge process?

1. Temperature of the aeration tank

2. Size of the aeration tank

3. Color of the effluent

4. Volume of chemical dosages

The correct answer is: Temperature of the aeration tank

The efficiency of the activated sludge process is significantly influenced by the temperature of the aeration tank. Temperature affects the metabolic activity of microorganisms, which are essential for the breakdown of organic matter in the wastewater. Warmer temperatures generally enhance microbial activity, leading to faster digestion and better treatment outcomes, while lower temperatures can slow down biological processes, resulting in less effective treatment. In contrast, while the size of the aeration tank can play a role in the treatment capacity, it does not directly impact the biological efficiency as temperature does. The color of the effluent is more of an indicator of treatment performance but does not influence the microbial activity within the aeration tank itself. The volume of chemical dosages could affect certain processes, but in the context of activated sludge, the biological temperature conditions have a more profound effect on overall efficiency.