A packed$-$tower stripping column $($the packing is used to promote air$-$water mass transfer$)$ is to be used as a pre$-$treatment to remove ammonia from an industrial wastewater. The feed stream now rate is $200,000m^3$ per day and has an $N{H}_3$ concentration of $450m\frac{g}{L}$ as $N{H}_3.$ The discharge permit allows a concentration of $20m\frac{g}{L}$ as $N{H}_3-N$ in the effluent stream.

a$)$ Calculate how many moles of $N{H}_3$ must be stripped per day.

b$)$ What is the removal efficiency of the stripping column in percentage?