Pre-treatment mechanisms during thermophilic-mesophilic temperature phased anaerobic digestion of primary sludge.
Pre-treatment is used extensively to improve degradability and hydrolysis rate of material being fed into digesters. One emerging process is temperature phased anaerobic digestion (TPAD), which applies a short (2 day) 50-70 degrees C pre-treatment step prior to 35 degrees C digestion in the main stage (10-20 days). In this study, we evaluated a thermophilic-mesophilic TPAD against a mesophilic-mesophilic TPAD treating primary sludge. Thermophilic-mesophilic TPAD achieved 54% VS destruction compared to 44% in mesophilic-mesophilic TPAD, with a 25% parallel increase in methane production. Measurements of soluble COD and NH(4)(+)-N showed increased hydrolysis extent during thermophilic pre-treatment. Model based analysis indicated the improved performance was due to an increased hydrolysis coefficient rather than an increased inherent degradability, suggesting while TPAD is suitable as an intensification process, a larger main digester could achieve similar impact.
AWMC, Advanced Water Management Centre, Environmental Biotechnology CRC, The University of Queensland, St Lucia, Brisbane, QLD 4072, Australia.
Huoqing
H
Ge
Paul D
PD
Jensen
Damien J
DJ
Batstone
D000693:Anaerobiosis; D012722:Sewage / Q000382:microbiology*; D013696:Temperature; D014865:Waste Disposal, Fluid / Q000379:methods*
D012722:Sewage