Water - March 2, 2009 -- A national food manufacturer experienced anaerobic digester upsets as a result of the influx of vegetable waste during "fresh vegetable season" production...

IFM IMPROVES METHANE GAS PRODUCTION IN ANAEROBIC DIGESTER THROUGH ADDITION OF MICRONUTRIENTS

Industrial Fluid Management
 

A national food manufacturer experienced anaerobic digester upsets as a result of the influx of vegetable waste during "fresh vegetable season" production. This created an imbalance in the volatile acid to alkalinity ratio in the digesters. The ultimate result of this condition was decreased methane gas production.

Tests indicated low pH levels (5.4) and alkalinity levels at 1000 mg/L as Calcium Carbonate. Operators adjusted alkalinity levels using standard powdered hydrated lime. This slowly increased and stabilized the alkalinity levels. However, methane gas production remained consistantly low and sluggish.

To boost methane gas production, operators fed IFM's Microbial Vitamin Source, a concentrated source of micronutrients, to the digesters to stimulate methanogenic bacterial activity. In contrast to nitrogen and phosphorus, micronutrients are required in relatively minor quantities but are equally as critical to healthy bacterial growth and organic degradation. Within one day, gas production began to increase, evidenced by an increase in the size of the burn flame.

To date, gas pressure inside the digesters remains high and constant with a consistently good burning flame. To maintain the digesters' efficiencies in this manner, operators continue to add a small dose of Microbial Vitamin Source weekly.