Mixing and Aeration in Biological-Treatment Plants: Examination of Existing Surface Aeration System Designs

摘要

Bench-scale and plant-scale studies were carried out to isolate the factors which affected mixing, aeration and solids suspension in existing carbonization activated-sludge treatment plants. The purpose was to improve existing plant and to assist in the design of new plant. The relative capabilities of the different systems were compared using flow pattern, floor velocities of flow and oxygenation capacity as criteria. It was concluded that some existing plant had inadequate oxygenation or sludge suspension and that these factors would have to be improved in future plant. In some conditions, one of these factors could be improved only at the expense of another. Due to the difficulties in selecting an aerator with sufficient oxygenation capacity, it is recommended that plant should incorporate a conservative overdesign of oxygen transfer potential.