Tennessee Wastewater Operator Practice Exam

Which issue is commonly associated with nitrification in a suspended growth reactor?

1. Nitrogen concentration

2. Hydrogen ion concentration

3. Oxygen depletion

4. Carbon source limitation

The correct answer is: Hydrogen ion concentration

Nitrification is a biological process carried out by specialized bacteria that convert ammonia to nitrite and then to nitrate. This process is highly dependent on the pH of the environment where it takes place. In a suspended growth reactor, maintaining an appropriate hydrogen ion concentration (which indicates pH) is crucial because nitrifying bacteria have an optimal pH range for functioning. If the pH becomes too low (acidic), it can inhibit the activity of these bacteria, slowing down the nitrification process. More specifically, the accumulation of acidity due to the conversion of ammonia can lead to a decrease in pH, thereby affecting bacterial health and their ability to effectively perform nitrification. While factors like nitrogen concentration, oxygen levels, and carbon sources can play important roles in wastewater treatment, it is the hydrogen ion concentration that most directly impacts the nitrification process in this context, making it the most relevant issue commonly associated with nitrification in a suspended growth reactor.