Passive aeration of wastewater treated by an anaerobic process-A design approach

Passive aeration units are units that operate without the need for electric energy. On the contrary to cascade and spray aerators, tray aerators require a much smaller area for their installation. While researching the design of tray aerators, the authors observed a shortage of literature pertaining to the topic. The research objective is to develop a model for the design of tray aerators for the purpose of increasing the dissolved oxygen in wastewater. The analysis focuses on the jetting free falling flow regime. This paper derives a set of equations that estimate the dissolved oxygen concentration in the effluent from the tray aerator system as a function of the flow rate, number of trays, tray area, spacing between trays, number and diameter of holes per tray. Results illustrate that the aeration performance is largely affected by the tray area, number of trays and flow rate while other parameters did not affect the aeration significantly.