This study was conducted to investigate the effects of inoculum and carbon sources on anaerobic digestion characteristics. The treatments were combinations of inoculum (digestate of cattle manure and rumen fluid) with carbon sources (starch, cellulose, and xylan). Anaerobic digestion was performed in triplicate at 37°C for 18 days at 100 rpm. Sampling was performed at 0, 1, 2, 3, 4, 5, 7, 9, 12, 15, and 18 days to measure pH, ammonia-N, volatile solids reduction, the cumulative methane content, and the cumulative methane production. There was a significant difference in methane content depending on the carbon source and there was a significant difference in pH, ammonia-N, methane production, and methane content depending on the inoculum (P < 0.05). The results of methane production were higher in the digestate of cattle manure treatment than in the rumen fluid treatment (P < 0.05). In this study, different digestive patterns depending on the type of carbon source could be used as basic research data to set the hydraulic residence time of anaerobic digestion facilities. In addition, the use of ruminal fluid as an inoculum may help accelerate the hydrolysis and acid production steps.

This study was conducted to investigate the effects of different carbon sources on the anaerobic fermentation characteristics in the startup phase using the biochemical methane potential test. The treatments for this experiment were combinations of carbon sources (starch, cellulose, and xylan). Anaerobic fermentation was done at 37oC for 18 days with agitation and pH, ammonia nitrogen, volatile solids reduction, gas production, methane content, and methane production were investigated at 0, 1, 2, 3, 4, 5, 7, 9, 12, 15, and 18 days after incubation in triplicate. In the experiment, the pH was changed depending on the characteristics of the carbon source. The ammonia nitrogen concentration was the highest in the starch-treated group at 7, 12, and 15 days after incubation (P < 0.05). Cumulative volatile solids reduction was the highest in the cellulose-treated group at 18 day after incubation (P < 0.05) and cumulative gas production was higher in the cellulose-treated group than for other two treatments at 18 day after incubation (P < 0.05). Methane content was the lowest in the xylan-treated group at 18 days after incubation (P < 0.05). Cumulative methane production was higher in the xylan-and cellulose-treated group than in the starch-treated group at 18 days after incubation (P < 0.05). In this study, the carbon sources had significant effects on anaerobic fermentation characteristics; especially, the carbon source was shown to have a positive effect on the operation time and hydraulic retention time for the anaerobic digestion startup phage. Therefore, carbon sources should be considered systematically for efficient anaerobic digestion of organic waste.