Tennessee Wastewater Operator Practice Exam

What is a result of activated sludge processes that incorporate denitrification?

1. They produce more sludge

2. They generate less sludge

3. They reduce energy costs

4. They require more operator supervision

The correct answer is: They generate less sludge

In activated sludge processes that incorporate denitrification, the overall result is the generation of less sludge compared to traditional methods. Denitrification allows for the conversion of nitrate in the wastewater to nitrogen gas, which is then released into the atmosphere. This process not only removes nitrogen but also utilizes organic matter as an electron donor, which means that less biomass (or sludge) is produced as a byproduct of the treatment process. Traditional activated sludge systems can lead to high sludge production, as the primary goal is to promote the growth of microorganisms that break down organic materials. However, with denitrification, a portion of the organic material is directed towards denitrifying bacteria instead of solely biomass growth, effectively reducing the amount of waste activated sludge that is produced. This principle is important in wastewater treatment facilities aiming for efficient waste management and lower operational costs, as managing and disposing of excess sludge can be resource-intensive. By generating less sludge, facilities can also reduce their maintenance and handling requirements, contributing to more sustainable operations.