Wastewater Treatment Operator Certification Practice Test

How does temperature generally affect the reaction rate of microorganisms in wastewater treatment?

1. Reaction rate doubles with every 18 degree Fahrenheit increase

2. Reaction rate decreases by 20% with every 10 degree Fahrenheit increase

3. Temperature has no significant impact on reaction rate

4. Reaction rate goes to zero at high temperatures

The correct answer is: Reaction rate doubles with every 18 degree Fahrenheit increase

The relationship between temperature and the reaction rate of microorganisms in wastewater treatment is often described by the general rule that a ten-degree Celsius (or approximately 18-degree Fahrenheit) increase in temperature can lead to a doubling of reaction rates in biological processes. This is largely due to the fact that higher temperatures increase the kinetic energy of molecules, leading to more frequent and effective collisions between enzymes and substrates, which in turn accelerates metabolic processes. This principle is essential in the context of wastewater treatment because microorganisms play a critical role in breaking down organic matter. An optimal temperature range enhances microbial activity, promoting faster degradation of waste and improving treatment efficiency. The rule does have limits and is not linear at extreme temperatures, as excessively high temperatures can cause denaturation of enzymes or even inhibit microbial activity altogether. Therefore, while temperature is a crucial factor in maximizing reactions in wastewater treatment, it also emphasizes the need for maintaining an appropriate thermal environment to sustain microbial health and performance.