Modeling of an Airlift Reactor with Floating Solids for Wastewater Treatment

This paper presents a three-phase reactor fluid dynamic model that is used in the development of a generic process for upgrading existing wastewater treatment plants. The core of the process consists of an attached growth airlift reactor (AGAR) in which a biomass carrier is used. Mixing is provided in the aerobic stages by partitions that create an airlift effect. The combination of the organized flow pattern and the low density of the media enables prevention of carrier migration between different process stages, without need of screens. Measurements of liquid velocity in a demonstration plant confirm the predicted values with reasonable accuracy.