Health Care Uses:

In medicine, oxygen is used during surgery, intensive care treatment, inhalation therapy, etc. High standards of purity and handling must be maintained.

Oxygen is typically supplied to hospitals though bulk liquid deliveries, then distributed to usage points.  It assists with respiratory problems, saving lives and increasing patient comfort.  

Small portable non-cryogenic air separation units are gaining wide use in home care. Larger scale units using which also use non-cryogenic air separation technology, are being utilized in small and/or remote hospitals where demand is high enough to make cylinder deliveries a logistical problem but where liquid deliveries are unavailable or very costly. These units typically produce 90 to 93% purity oxygen, which is adequate for most medical uses. 

Environmental:

In the biological treatment of waste-water, the use of oxygen instead of air permits increased capacity in existing treatment plants.  Injecting oxygen into sewers reduces hydrogen sulfide formation, which results in reduced corrosion and odor. 

Ozone is used for drinking water treatment, in particular when alternatives, such as chlorine, are undesirable.