Covering a concrete manure storage tank with an air-tight floating membr ane should
induce anaerobic digestion of the stored manure. If the microbial community in the
manure can acclimate to the ambient conditions, then In-Storage Psy chrophilic Anaerobic
Digestion (ISPAD) could be used by Canadian livestock pro ducers to produce methane and
stabilize manure. The objective of this study was to determine whether the microbial
community in swine manure can succes sfully acclimate to the psychrophili c operating
conditions in ISPAD and develop robust anaerobic digestion. This was done in the laboratory by analyz ing manure from a three-year old full-scale pilot ISPAD facility located in
St. Francois Xavier, Quebec, Canada, along with fresh manure and manure from an
uncovered storage tank. Biochem ical metha ne product ion assays performed at the three
temperatures were used to quantify the performance of the microbial communi ty and its
temperature dependenc e. The ISPAD microbial community produced methane, in terms of
VS added, at rates of 44.6, 9.8 and 8.5 dm3 kg1 d 1, at 35, 18 and 8 C, respectively. The
ISPAD process reduced the organic matter content of the manure by 24% while releasing
63% of the potential methane in the manure, as opposed to the open storage tank where no
measurable reduction in solids occurred, and only 15% of the potential methane was
released. These results indicate that a robust, acclimated microbial community actively
digests manure in the pilot ISPAD installation.