I've spent most of a career trying to keep disolved oxygen out of "Piping and Fluid Mechanics" systems. It accelerates corrosion in steel pipes.
If you are trying to get disolved oxygen into a pond (for example) you can expect to add about 2.5-5.0 lbm/hp-day of aeration pumps. This is a really strange set of units, but that is the way the literature discusses it. So if you have a 10 hp pump you'll add 600 -1,200 lbm/day to a pond. Then you just have to know the pond size to know how much you've changed the ppm.
Bubbling some air through a PVC pipe will do almost nothing to aid the aeration of a sizeable pond (this technique works fine for an aquarium, but it doesn't scale up very well).
