ANALYSIS OF THE INFLUENCE OF ENVIRONMENTAL AND OPERATINAL EFFECTS IN TRANSFERING OF DISSOLVED OXYGEN SYSTEMS IN ACTIVATED SLUDGE

Abstract

The aeration in the aerobic biological treatment systems, such as the activated sludge system is applied to effect the transfer of atmospheric oxygen into the mixed liquor, where the transferred oxygen is being consumed in general, for oxidation of organic material present with subsequent release of energy and production of new cells of aerobic organisms responsible for oxygen consumption. The energy for aeration is usually the largest factor in operating costs for activated sludge systems and often exceeds 50 % of maintenance costs due to operational problems and sizing. Experimental investigations were conducted to determine the influence that factors such as temperature, concentration of suspended solids and dissolved salts can exert on the oxygenation capacity (OC) in order to improve the design criteria and the choice of aerators. The studies showed that all these factors influence the OC, some may reduce its capacity by 50 % (as is the case of solids concentration). Keywords: aeration, biological treatment, temperature, salts, solids.