Organic removal rates and biogas production of an upflow anaerobic sludge blanket reactor treating sugarcane molasses

Abstract

Response surface methodology was used to develop an empirical model for the optimisation of feed carbon to nitrogen ratio and temperature of an upflow anaerobic sludge blanket reactor treating sugarcane molasses. The developed quadratic models were found to be statistically significant (Prob > F values: 0.0747 and 0.0495) and there was a good correlation between predicted and actual values (R2 values: 0.80 and 0.65). The results indicated that carbon to nitrogen ratio and temperature interactions had a significant effect on biogas production and organic removal rate. Within the range of parameters tested, the optimal biogas production (0.832 L/L.d) and organic removal rates (77.7%) were achieved at a temperature of 38 °C and a total organic carbon to nitrogen ratio of 22:1 (wt/wt). The reactor exhibited the potential to generate energy through biogas formation with a rich methane content of 66.5 vol%.