A Comprehensive Aeration System Model for WRRF Design and Control

During the design of a water resource recovery facility (WRRF), it is becoming industry practice for process engineers to use simulation software to assist with the design of the plant and its aeration system. The aeration process is one of the key components of the activated sludge process, and as such, is one of the most important aspects of modeling wastewater treatment systems. A comprehensive aeration system model has been developed in SIMBA# that can model both the air supply and demand. The model includes sub-models for centrifugal and positive displacement blowers, pipes and fittings, valves, and diffusers. Both compressible and incompressible flow can be modelled. Oxygen transfer within aeration tanks is also included as part of the overall model. The aeration system model allows engineers to analyze aeration systems as a whole to determine biological air requirements, blower performance, air distribution, control valve impacts, and controller design and tuning. This will allow more detailed system-wide testing before commissioning.