2.2 Anaerobic bioreactors
The 6 liters bioreactors were custom built from polyethylene tanks. The middle of the reactor was installed with a shaft of impeller for mixing. Each reactor was equipped with two outlet ports; one for liquid sample withdrawal or for new organic loading in case of fed batch operation mode was running. The other was for gas passing to a gas collecting system base on water displacement by the existing gases.
2.3 Operation
Biogas production was started up by applying
with chopped pineapple peel solid waste consisted of initial COD of 20,000 mg/l. This raw material was composed to fill up to approximately 4.8 liters working volume of the reactor. Single stage batch processes were operated at ambient temperature with 2 times of mixing per day for 30 days. The effects of pH value of the system, carbon to nitrogen (C/N) ratio were performed through the experiments. The observation of total amount of