River water aeration is often required in water bodies that suffer from low oxygen conditions caused by sewage discharges, agricultural run-off, or heavy rain. FlowMixer was evaluated in an European Union project for the river Dommeln in the Netherlands.

River aeration may required when during heavy rainfalls enormous masses of water fill up rivers and increases the BOD (Biological Oxygen Demand) and COD (Chemical Oxygen Demand) of the water. 

As a result the oxygen levels in the water decreases endangering the aquatic life and releasing chemical substances. 

River aeration provides oxygen to bacteria for treating and stabilizing the wastewater. Oxygen is needed by the bacteria to allow bio-degradation. The O2 is used by bacteria in the water to break down organic matter containing carbon. Without sufficient dissolved oxygen, degradation occurs and the biological process convert hydrogen and sulfur to form hydrogen sulfide and methane.

The FlowMixer technology for river aeration was evaluated in a large-scale project financed by EC (European Commission) and done in collaboration with the Municipality of Eindhoven, Waterschap de Dommel, and the Technical University of Eindhoven.

The pilot project showed that the average amount of oxygen that was introduced into the river varied between 9,5 kg/O2/h (dry weather conditions) to 17 kg/O2/h wet weather conditions. The expected values were between 3 to 5 kg/O2/h.