What is considered enriched oxygen level?

The concept of enriched oxygen levels refers to the concentration of oxygen in the air, primarily in the context of its role in biological processes, such as wastewater treatment. Typically, the normal concentration of oxygen in the atmosphere at sea level is around 21%. Enriched oxygen levels are generally considered to be any levels above this baseline, indicating an increase in oxygen concentration that can enhance the efficiency of aerobic processes in wastewater treatment.

The choice of 21.5% as enriched oxygen reflects a slight increase above the normal atmospheric level. This level provides an environment that can significantly benefit aerobic microorganisms, improving the treatment process by promoting their growth and activity. This is particularly important in systems where oxygen demands are high, such as in active biological treatment methods.

In contrast, levels such as 19.0% or 20.5% do not represent significant enrichment and might not provide the enhanced conditions needed for maximizing the aerobic processes effectively. Similarly, 24.0% is markedly high and can lead to other complications, such as fire hazards or equipment damage. Thus, 21.5% is recognized as an effective enriched oxygen level for fostering better aerobic biological treatment processes without entering a range that could be considered excessive or dangerous.