Of course there are differences between wastewater and ponds. I tried to point out the major one being flow dynamics. There are also obvious differences between a pond vs. sludge and water in a jar. But I think there is something to be learned from both as the biochemical process' responsible for digesting the sludge are essentially the same in all three scenarios.
There are plenty of aerated facultative lagoons that stock fish in the final treatment cell. The purpose of the fish is to eat the bacteria and invertebrates that have fed on the bacteria therefore converting the wastes into fishy biomass. In this way and others, wastewater treatment can be similar to a pond. The fish are then harvested for several different uses.
I tried to find documentation online and you are all correct, there is not much out there aside from information on wastewater. I actually went 10 pages deep on a couple of google searches and found nothing on ponds. Perhaps this is because the stakes are a lot higher in a wastewater treatment plant than a private "recreational" pond. What would drive a peer reviewed paper on a topic that impacts so few people? Just a thought...
Anyone out there looking for a masters thesis topic?
BC, was it you who did that jar test?