Kinetics of Pure Oxygen Activated Sludge

No difference in the pertinent kinetic parameters has been found in experiments comparing two activated sludge systems one aerated by air and the other by pure oxygen. The kinetic parameters that were compared, evaluted, and found identical are: yeild coefficient, decay coefficient, and substrate removal coefficient. The two systems operated under identical conditions except for the dissolved oxygen concentrration in the aeration tank, i,e., 0.3 mg/l to 3.0 mg/l in the air system, and 10 mg/l to 18 mg/l in the pure oxygen system. The difference in dissolved oxygen in both systems has not shown any effects on the sludge settling characteristics as expressed by the sludge volume index and sludge settling rate, when identical conditions of biomass concentration and solids retention time prevailed. Contrary to some claims, the results proved that the advantages of pure oxygen lie solely in oxygen higher partial pressure and the corresponding driving force of its dissolution.