What happens to the anoxic zone?

Short Answer:

Nanobubbles are applied in a way that avoids disrupting anoxic or anaerobic zones.

In-Depth Answer:

Nanobubble systems are applied as a pretreatment or process‑conditioning step and are not intended to increase bulk dissolved oxygen in anoxic or anaerobic zones. The amount of oxygen associated with nanobubble pretreatment is small relative to overall process demand and is applied upstream. System placement and operating strategies are designed to support existing process configurations, including nitrification–denitrification schemes, without compromising anoxic or anaerobic conditions.