Question

the amount of oxygen required by nitrifiers for nitrification in wastewaters is represented by

Answer 1

The amount of oxygen required for nitrifying 1kg of nitrogen is 4.6kg of  oxygen.

Answer 2

The amount of oxygen required by nitrifiers for nitrification in wastewater is that approximately 4.6 kg of oxygen are required for every kg of ammonium ions.

But the actual and maximum nitrification occurs at dissolved oxygen level which is at 3.0 mg per liter that’s why nitrification maintains lesser or equal the amount of oxygen dissolves.