DYNAMIC PREDICTION OF WASTE-WATER AERATION BASIN TEMPERATURE

A dynamic model was developed to predict activated-sludge aeration bas in temperature. The model accounts for hourly or more frequent changes in weather conditions and input parameters such as wastewater tempera ture, aeration, and biological reaction. The model was verified using data from full-scale treatment plants located across the United States . The various heat transfer terms are evaluated, and the relative cont ribution from each is shown. Evaporation from aeration can be a major component. Surface aerators cool the basin much more than diffused aer ation systems. Diffused aeration systems are preferred for cold climat es. The heat of biological reaction is small, except for very high rat e processes. The effect of changing weather conditions, such as a cold front, can be predicted. Local relative humidity has a major impact o n cooling. The impact of design changes, such as covering an aeration basin, insulating walls, or changing retention times, can be determine d using the developed model.