Abstract:
A single stage pilot scale anaerobic reactor of 50 Litter volume was
constructed to conduct dry anaerobic co-digestion of sludge and rice husk.
Reactor was started with batch start-up phase followed by semi-continuous
phase. Total solid content and C: N ratio of waste mixture used in this
research was maintained at 15% and 30 respectively. Mesophilic
temperature range was maintained in reactor. Effect of variation in organic
loading rates of biogas production was examined in semi-continuous phase.
For this purpose the reactor was operated at OLR of 2, 4, 6 and 8 kg VS/m 3
/d. Results revealed that in comparison of OLR 2, 4 and 8 OLR 6 had higher
biogas production rate. Average specific biogas yield of 142 L/kg/VS with
%VS removal of 63% was achieved. For OLR 2, 4 and 8 these were 113,
94, 115 and 76, 61, 47%.Reactor performance decreased with at OLR 8 due
to Volatile fatty acids accumulation and inhibition of biogas production.
Thus based on biogas production and stability of anaerobic reactor, OLR 6
kg VS/m 3 /d was considered to be most optimum for dry anaerobic codigestion
of waste sludge and rice husk.
