What alkalinity is roughly required to convert 1 mg/L of ammonia to nitrate?

What alkalinity is roughly required to convert 1 mg/L of ammonia to nitrate?

• A. 3.0 ppm
• B. 10.0 ppm
• C. 2.0 ppm
• D. 7.2 ppm

Answer: (D)

Nitrification uses up buffering alkalinity as ammonia is oxidized to nitrate, releasing acidity. The stoichiometry works out to about 7.14 mg/L of alkalinity as CaCO3 being required for every 1 mg/L of ammonia-nitrogen oxidized to nitrate. So, to convert 1 mg/L of ammonia to nitrate, roughly 7.2 mg/L (ppm as CaCO3) of alkalinity is needed. That’s why 7.2 ppm is the best fit. The other values are not close to the required buffering amount for this nitrification load.

Nitrification uses up buffering alkalinity as ammonia is oxidized to nitrate, releasing acidity. The stoichiometry works out to about 7.14 mg/L of alkalinity as CaCO3 being required for every 1 mg/L of ammonia-nitrogen oxidized to nitrate. So, to convert 1 mg/L of ammonia to nitrate, roughly 7.2 mg/L (ppm as CaCO3) of alkalinity is needed. That’s why 7.2 ppm is the best fit. The other values are not close to the required buffering amount for this nitrification load.