Tennessee Wastewater Operator Practice Exam

The process of consuming CBOD with nitrate is known as what?

1. Nitrification

2. Denitrification

3. Fermentation

4. Decaying

The correct answer is: Denitrification

The process of consuming carbonaceous biochemical oxygen demand (CBOD) with nitrate is known as denitrification. During denitrification, bacteria use nitrate as an electron acceptor to oxidize organic matter, such as CBOD. This process typically occurs in anaerobic conditions and results in the reduction of nitrate (NO3-) to nitrogen gas (N2), which is released into the atmosphere. Denitrification is a crucial part of the nitrogen cycle and helps in reducing the overall nitrogen load in wastewater, contributing to improved water quality. By understanding this process, wastewater operators can better manage nutrient levels in wastewater treatment systems, ensuring effective removal of pollutants. In contrast, nitrification does not consume CBOD but rather involves the oxidation of ammonia to nitrite and then to nitrate by aerobic bacteria. Fermentation is a metabolic process that converts carbohydrates to acids or alcohol under anaerobic conditions but does not specifically refer to the consumption of CBOD with nitrate. Decaying refers to the breakdown of organic matter, which may involve microbial activity but is not specifically tied to the process of consuming CBOD with nitrate.