Simple protocols for assessing dissolved air flotation systems: quantification of released air, bubble density and cloud patterns

Dissolved air flotation (DAF) systems are useful for many water treatment applications. Optimizing a DAF system can be very difficult and complicated due to a multitude of variables that contribute to effective separation. Pressure, temperature, retention time and air mixing affect the ability of the saturator to increase air solubility, while baffle heights, flow rates and recycle ratios affect how the air that is released from solution interacts with the treated water. This paper focuses on two simple test protocols for quantifying dissolved air concentration in the recycle water and bubble density in the flotation tank. The primary purpose of this paper is to assist individual operators, technicians and engineers to develop their own protocols for their specific water and test conditions. A sample calculation is also included to illustrate the significance of these quantification protocols, which can be further modified as needed for a given set of parameters and variables.