As I tell all of our clients, aeration is NOT a cure all item or tool in the proverbial aquatic tool box.
It is a very STRONG air tool (lets say equal to an air impact wrench to a mechanic) but other things play into the mix (punn intended) when aerating a waterbody.
Infact, the water/air interface is where all the magic is happening. The O2 transfer is less than 5% from the actual bubble.
I just visited a site that we installed 15 diffusers on (45 acre lake). The lake manager stated that there was a trend of increasing visibility over the past 3-years. From 12" to now 3+ feet using the secci disc.
This has translated into positive beneficial plant growth, increased freshwater mussel populations and a benthic layer alive with organisms found in mesotrophic lakes and ponds.
This lake uses an integrated approach using selective herbicides, triploid grass carp, physical removals, bottom aeration and horizontal circulators for dead end canals.
They have also pushed the city to install collectors or leaf traps in the stormwater outlets prior to discharging into the lake.
All of these equal a healthy lake.
As for the physics, what you posted Bruce is excactly happens. We use the bubbles as a lifting apparatus opposed to actually transferring oxygen. There are cases where the bubble transfer for example the TVA (Tennessee Valley Athority) pumps pure oxygen down to a series of diffusers at the bottom of a dam to increase the oxygen levels at a depth of 100 foot plus but that is not the standard.
Circulation, light penetration, a healthy plant population, a healthy bacteria population and removal of excessive nutrients are all the key to a good healthy lake or pond.
