Good afternoon. We have encountered a situation where a company has a large collection of FOG/water/trash materials, mostly high FFA deriving from food processing waste and trap grease. Some of the material is as old as 20 years. We are attempting to remove the material and help the customer clean the area.

What we are trying to determine is what happens to the FOG material over time. It has likely been exposed to all conditions ranging from general atmospheric fluctuations to aerobic and anaerobic digestion.

Does anyone have any direction to research papers or studies on the subject? Even some basic explanations would be appreciated.