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A novel process configuration for anaerobic digestion of source‐sorted household waste using hyper‐thermophilic post‐treatment
Author(s) -
Hartmann Hinrich,
Ahring Birgitte K.
Publication year - 2005
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.20485
Subject(s) - biogas , chemistry , thermophile , anaerobic digestion , hydraulic retention time , pulp and paper industry , effluent , methane , ammonia , hydrolysis , waste management , continuous stirred tank reactor , bioreactor , yield (engineering) , organic chemistry , materials science , engineering , metallurgy , enzyme
A novel reactor configuration was investigated for anaerobic digestion (AD) of the organic fraction of municipal solid waste (OFMSW). An anaerobic hyper‐thermophilic (68°C) reactor R68 was implemented as a post‐treatment step for the effluent of a thermophilic reactor R1 (55°C) in order to enhance hydrolysis of recalcitrant organic matter, improve sanitation and ease the stripping of ammonia from the reactor. The efficiency of the combined system was studied in terms of methane yield, volatile solids (VS) reduction, and volatile fatty acid (VFA) production at different hydraulic retention times (HRT). A single‐stage thermophilic (55°C) reactor R2 was used as control. VS reduction and biogas yield of the combined system was 78–89% and 640–790 mL/g VS, respectively. While the VS reduction in the combined system was up to 7% higher than in the single‐stage treatment, no increase in methane yield was observed. Shifting the HRT of the hyper‐thermophilic reactor from 5 days to 3 days resulted in a drop in the methanogenic activity in the hydrolysis reactor to a minimum. Operation of R68 at HRTs of 24–48 h was sufficient to achieve high VS conversion into VFAs. Removal of pathogens was enhanced by the hyper‐thermophilic post‐treatment. 7% of the ammonia load was removed in the hyper‐thermophilic reactor with a flow of headspace gas through the reactor equivalent to four times the biogas flow produced in reactor R1. © 2005 Wiley Periodicals, Inc.