The anaerobic digestion of substrate (distiller grain, swine manure and food waste) is a
process that has become a promising technology in waste management through the world.
Thus, the main goal of this thesis was to find better substrate, optimum I/S ratio and C/N
ratio for anaerobic digestion under continuous process. In addition, this research was tested
appropriate substrate, optimum I/S ratio and C/N ratio in anaerobic digestion process by
BMP test.
Biochemical methane potential assay were conducted on several representative substrate
components to determine the ultimate biodegradability and conversion efficiency. BMP
test was operated under mesophilic condition (37°C). Base on the result obtained that
swine manure is better substrate for this experiment because it can produce specific
methane production around 159.24 L/kg VS and present methane around 59.26%. The
result shows that the highest percent methane around 68.93% and biogas production
around 9357.67mL was observer at I/S 2. The highest specific methane production was I/S
3 around 843.71 L/kg VS. From result, swine manure C/N 30 has highest specific methane
production around 827.86 L/kg VS, highest percent of methane around 73.98% and highest
methane volume around 7813.03mL. It concludes that swine manure at I/S ratio 2 and C/N
ratio 30 is better ratio for mixture substrate in this experiment.
Reactor experiment was researched to find optimum I/S ratio and C/N ratio. Reactor
experiment was operated under mesophilic condition (37°C). Operation reactor has two
phases i.e. start-up phase and continuous phase. In final phase, experiment was conducted
for three different loading which operate 25 days in each loading. Base on the result
obtained that I/S ratio 2 can produce the methane yield around 405.29 L/kg VS and highest
percent methane around 59.44%. the highest volatile solid removal of 30.95% was
observer at I/S 2. C/N ratio variation was tested to research appropriate C/N ratio under
continuous process. This study found that as organic loading rate increased, the biogas
production increased. The methane yield of C/N 30 obtained was 259 L/kg VS, 473 L/kg
VS and 462 L/kg VS from OLR 2, 3.5 and 5 kg VS/m
3
.day. However, when loading was
increase to 5 kg VS/m
3
.day, the significant deterioration of biogas composition as well as
production was observed. The highest percent methane around 68.47 % at OLR 3.5 kg
VS/m
3
.day was observed at swine manure C/N ratio 30. The volatile solid removal of
24.49%, 22.05% and 18.81% were obtained during the 2, 3.5 and 5 kg VS/m
3
.day
respectively. These were observed at swine manure C/N ratio 30.