title: Mesophilic and thermophilic anaerobic co-digestion of rendering plant and slaughterhouse wastes.
abstract: Co-digestion of rendering and slaughterhouse wastes was studied in laboratory scale semi-continuously fed continuously stirred tank reactors (CSTRs) at 35 and 55 °C. All in all, 10 different rendering plant and slaughterhouse waste fractions were characterised showing high contents of lipids and proteins, and methane potentials of 262-572 dm(3)CH(4)/kg volatile solids(VS)(added). In mesophilic CSTR methane yields of ca 720 dm(3) CH(4)/kg VS(fed) were obtained with organic loading rates (OLR) of 1.0 and 1.5 kg VS/m(3) d, and hydraulic retention time (HRT) of 50 d. For thermophilic process, the lowest studied OLR of 1.5 kg VS/m(3) d, turned to be unstable after operation of 1.5 HRT, due to accumulating ammonia, volatile fatty acids (VFAs) and probably also long chain fatty acids (LCFAs). In conclusion, mesophilic process was found to be more feasible for co-digestion than thermophilic process, methane yields being higher and process more stable in mesophilic conditions.
authors.affiliation: University of Jyväskylä, Department of Biological and Environmental Science, P.O. Box 35, FI-40014 University of Jyväskylä, Finland. suvi.bayr@jyu.fi
authors.forename: Suvi
authors.initials: S
authors.lastname: Bayr
authors.forename: Marianne
authors.initials: M
authors.lastname: Rantanen
authors.forename: Prasad
authors.initials: P
authors.lastname: Kaparaju
authors.forename: Jukka
authors.initials: J
authors.lastname: Rintala
mesh_terms: D000003:Abattoirs; D001421:Bacteria, Anaerobic / Q000145:classification* / Q000378:metabolism*; D019605:Euryarchaeota / Q000145:classification* / Q000378:metabolism*; D007220:Industrial Waste / Q000517:prevention & control; D008697:Methane / Q000378:metabolism*; D012722:Sewage / Q000382:microbiology*
chemical_list: D007220:Industrial Waste; D012722:Sewage; D008697:Methane