Tennessee Wastewater Operator Practice Exam

Which factor is essential for the effective operation of an aerobic digester?

1. High ambient temperature

2. Constant pH levels

3. Effective mixing of contents

4. Low nutrient input

The correct answer is: Effective mixing of contents

The effective operation of an aerobic digester relies heavily on the proper mixing of its contents. Continuous and effective mixing ensures that the microorganisms within the digester are evenly distributed throughout the sludge. This mixing facilitates the optimal interaction between microorganisms and the organic matter they are tasked with breaking down, enhancing the digestion process. Furthermore, proper mixing helps maintain a uniform temperature and prevents the formation of sludge mats or foaming, which could hinder the efficiency of the digestion process. It also aids in gas release and prevents the accumulation of non-degradable materials. Overall, ensuring that contents are mixed effectively is critical for maximizing the biological activity necessary for successful aerobic digestion.