Are Your Digesters Burping, Frothing, or Otherwise Not Behaving? – Let’s talk about Solutions and NOT REPEAT the “Digester Foam” Paper you’ve already Heard Five Times

Unlike almost all other process units at a water resource recovery facility (WRRF) anaerobic digesters are inaccessible to gain first-hand information about the processes going on inside. This means that essentially all of our data is currently, and has always been, derived from instrument reading and from samples extracted from the digesters. We have necessarily developed inferences and assumptions from those data. Some of these inferences have been wrong and this paper is about one such “convention” that if revamped, solves many of the more persistent problems in digesters: the false convention is that the contents of digesters have the specific gravity (SG) equivalent to, or very close to that of water.This paper reviews conventional “problem” designs within the context of this new understanding and provides guidance on how future designs could be adapted to limit these detrimental effects. Possible retrofit to conventional design will also be discussed.