Kinetics of the Desorption of Ammonia from Water by Diffused Aeration

Abstract Ammonia desorption by diffused aeration was investigated in a lab-scale, batch aeration column, and the theoretical basis for the operation was developed. A formula was derived for the calculation of the fraction of ammonia present in the solution in undissociated form (susceptible for desorption) for any given temperature and pH. The experimental work shows that desorption is equilibrium controlled, which is at variance with some of the results reported in the literature. Lower limits of the ammonia mass transfer coefficient for bubbles rising through the water column were estimated. The impact of the surface effect on the rate of desorption was taken into account in the calculations.