Chloramine residuals can undergo which process over time, releasing which compound, that can promote nitrification?

• A. Auto decomposition, ammonia
• B. Auto decomposition, nitric oxide
• C. Biological decomposition, nitrogen
• D. Biological decomposition, nitrate

Answer: (A)

Chloramine residuals slowly break down through auto-decomposition, and this process releases ammonia. That ammonia serves as the food source for nitrifying bacteria, allowing nitrification to proceed—converting ammonia to nitrite and then to nitrate—and in the process can erode the chloramine residual. This is why ammonia is the compound released and why it promotes nitrification. The other options don’t fit because they involve either the wrong process or the wrong released species; nitrification starts with ammonia, not nitric oxide or nitrate, and biological decomposition isn’t the mechanism described for the initial release in this context.