Would have to be somewhat skeptical as the aeration system in activated sludge systems is also used to mix the tanks. This technology doesn't appear to be capable of mixing. Perhaps the technology may be used with a mechanical mixer.
I have not designed such systems, but a sub-contractor installed a system as part of a project that I managed. So I have seen it work, but do not have any technical details.
I would agree with bimr that it is not suitable for mixing, but the application where I saw it work involved waxes in the waste water and the aim was to float the waxes and then skim them off so we did not want any bulk mixing. This particular application achieved its goal so I would say the technology is useful when correctly applied.
You have not elaborated on what nano-bubble system you are specifically referring to. However most of the performance claims made by nano-bubble enthusiasts do not follow the laws of chemistry and physics.
Regards
Ashtree
"Any water can be made potable if you filter it through enough money"
Not sure if this is the same application you are inquiring about, but I had a municipal client with a 0.3 MGD two cell lagoon that replaced their coarse bubble static aerators with micro bubble diffusion (MBD) aerators. The reduction was from 101 static tubes to 8 floating MBD aerators. The state permitting agency had some concerns with performance and only conditionally permitted it.
