Gupta, M.; Gomez-Flores, M.; Nasr, N.; Elbeshbishy, E.; Hafez, H.; Hesham El Naggar, M.; Nakhla, G.
초록
In this study, batch tests were conducted to investigate the performance of mesophilic anaerobic digester sludge (ADS) at thermophilic conditions and estimate kinetic parameters for co-substrate fermentation. Starch and cellulose were used as mono-substrate and in combination as co-substrates (1:1 mass ratio) to conduct a comparative assessment between mesophilic (37<SUP>o</SUP>C) and thermophilic (60<SUP>o</SUP>C) biohydrogen production. Unacclimatized mesophilic ADS responded well to the temperature change. The highest hydrogen yield of 1.13mol H<SUB>2</SUB>/mol hexose was observed in starch-only batches at thermophilic conditions. The thermophilic cellulose-only yield (0.42mol H<SUB>2</SUB>/mol hexose) was three times the mesophilic yield (0.13mol H<SUB>2</SUB>/mol hexose). Interestingly, co-fermentation of starch-cellulose at mesophilic conditions enhanced the hydrogen yield by 26% with respect to estimated mono-substrate yields, while under thermophilic conditions no enhancement in the overall yield was observed. Interestingly, the estimated overall Monod kinetic parameters showed higher rates at mesophilic than thermophilic conditions.