The PS was located in the third chamber of a gravity flow filter. A pump was drawing out of this chamber and Teed off to feed both the PS and the return to the pond. The foam is carried up through the Y by the air flow pulled down through the PS by the falling water. An air pump located under the PS would probably enhance this effect.
Basically, Yes.
Everyone Knows that TTs or Shower filters tend to produce a stable foam. This is one method to collect and remove it. It may not be the best way for all situations , but it could work well in some.
Dan