Solution: Nitrification is a biological process for removing NH 3 from wastewater as NH4+:NH4+ + 2 O 2 ⟶ NO3− + 2 H+ + H2OThe first-order rate constant is given ask1 = 0.47e0.095(T − 15˚C)where k1 is in day −1

Nitrification is a biological process for removing NH _{3} from wastewater as NH_{4}^{+}:

NH_{4}^{+} + 2 O _{2} ⟶ NO_{3}^{−} + 2 H^{+} + H_{2}O

The first-order rate constant is given as

k_{1} = 0.47e^{0.095(T − 15˚C)}

where k_{1} is in day ^{−1} and T is in ˚C. If the initial concentration of NH _{3} is 3.0 mol/m^{3}, how long will it take to reduce the concentration to 0.35 mol/m^{3} in the winter (T = 10˚C)?