초록
The influence of carbon dioxide (CO<SUB>2</SUB>) in the headspace gas on the specific methane (CH<SUB>4</SUB>) production of blank samples with just inoculum during Biochemical Methane Potential (BMP) tests was studied. The headspace of the bottles had been flushed with 15 different ratios of CO<SUB>2</SUB> and N<SUB>2</SUB> prior to incubation, while they were treated otherwise identically. The results revealed that the CH<SUB>4</SUB> yield increased linearly with higher ratio of CO<SUB>2</SUB> in the flush gas reaching a 30% higher yield at pure CO<SUB>2</SUB> relative to pure N<SUB>2</SUB> headspace conditions. However, a slightly distinct lag is noticeable during the initial phase of the degradation process at high ratios of CO<SUB>2</SUB>, hypothesizing a reversible disturbance of the biocenosis. Further experiments and analyses need to be performed to elucidate the underlying mechanisms.