Anaerobic digestion of brewery primary sludge to enhance bioenergy generation: a comparison between low- and high-rate solids treatment and different temperatures.
Anaerobic digestion of brewery wastewater solids in the form of primary sludge was investigated for its potential as a source of energy (methane). We operated a low-rate (hydraulic retention time (HRT)=solids retention time (SRT)) continuously stirred anaerobic digester (CSAD) and a high-rate (SRT>HRT) anaerobic sequencing batch reactor (ASBR) in parallel for 250 days. We found that high-rate anaerobic digestion was beneficial for solids-rich waste flows even during a long-term operating period that included a shock load of nonbiodegradable total solids. The ASBR biomass achieved a higher specific methanogenic activity compared to the CSAD biomass (0.257+/-0.043 vs. 0.088+/-0.008 g CH(4)-COD g(-1)VSS d(-1)), which aided in stability during the shock load with total solids. The methane yield for the ASBR was 40-34% higher than for the CSAD (0.306 vs. 0.219 l CH(4)g VS(-1) fed for days 1-183 and 0.174 vs. 0.130 l CH(4)g VS(-1) fed for days 184-250, respectively). Finally, we operated an ASBR for an additional 295 days to evaluate the effect of temperature variation on system stability. A stable performance was achieved between the operating temperatures of 22-41 degrees C.
Agler
Matthew T
MT
Department of Biological and Environmental Engineering, Cornell University, Riley-Robb Hall, Ithaca, NY 14853, USA.
Aydinkaya
Zeynep
Z
Cummings
Theresa A
TA
Beers
Allen R
AR
Angenent
Largus T
LT
D001421:Bacteria, Anaerobic / Q000502:physiology*; D001673:Biodegradation, Environmental; D001674:Bioelectric Energy Sources; D019149:Bioreactors / Q000382:microbiology*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008697:Methane / Q000378:metabolism*; D012037:Refuse Disposal / Q000295:instrumentation*; D012722:Sewage / Q000382:microbiology*
D012722:Sewage; D008697:Methane