One of the alternatives for ...
Published by Marina Vasiljevic, Sole Proprietor at M ENGINEERING ZONE
One of the alternatives for introduction of oxygen into the WWTPs is application of pure oxygen instead of air.
You could investigate the possibility to rent a mobile liquid oxygen tank and determine the necessary dose, if there are some liquid air supplier nearby.
the link of one of manufacturers is hereafter
https://advancedtech.airliquide.com/mobile-liquid-oxygen-storage-tank-purging-unit
In general, hospitals should have such type of units.