(Q2-3) Liquid water at 25C is to be aerated in a bubble column where finely air bubbles with diameter dg are injected co-currently with the liquid. The bubble column is 5 m high with a superficial liquid velocity of 0.3 m/s and a cross-sectional area of 3 m? The saturated oxygen concentration is 2.67x10-4 kmol/m. The mass transfer coefficient for the transfer of oxygen from the liquid interface to the bulk water is 5.8x106m/s. The diffusivity of oxygen in water is 2.42x10-9 m2/s. The volume fraction of the injected air is 0.1. The oxygen concentration in water is given by C = 2.67x10-4 - 2.55*10-4exp(-0.0696z), where z is the distance from the inlet and C is in kmol/m. At z = 2 m, determine the absorption flux of oxygen into water 1.887x10-9kmol/mxs 2.487x10-kmol/mxs 3.287x10-kmol/mxs 1.287x10-kmol/m2xs