초록
Batch experiments were conducted to evaluate the impact of inoculum sources, inoculum to substrate (IS) ratio and storage conditions on the potential and production rate of methane (CH<SUB>4</SUB>) from different substrates: wheat straw, whole crop maize, cattle manure, grass and cellulose. The results of the test with four inocula and four substrates indicated that inoculum source could have a significant impact on both CH<SUB>4</SUB> potential (BMP) and the kinetics parameters of different substrates. The two inocula showing the highest BMP and production rates in each period were those coming from a feeding with more than 70% of animal manure under thermophilic conditions. The impact of the IS ratio in the range 0.25-2.5, in terms of g volatile solids (VS) substrate/g VS inoculum, depended on substrate type. Maize silage was more affected to changes in the IS ratio than wheat straw. The optimal IS ratio range for maize was 1.0-1.5, however, a wider IS range can be used in wheat straw (0.5-2.5). The impact of freezing and drying depended on biomass type. Freezing, drying and ensiling of grass increased the CH<SUB>4</SUB> yield compared to fresh grass. Drying of maize had no impact while freezing reduced the CH<SUB>4</SUB> potential. Drying and freezing had no impact on straw.