title: Thermal pretreatment of the solid fraction of manure: impact on the biogas reactor performance and microbial community.
abstract: Application of thermal treatment at 100-140 degrees C as a pretreatment method prior to anaerobic digestion of a mixture of cattle and swine manure was investigated. In a batch test, biogasification of manure with thermally pretreated solid fraction proceeded faster and resulted in the increase of methane yield. The performances of two thermophilic continuously stirred tank reactors (CSTR) treating manure with solid fraction pretreated for 40 minutes at 140 degrees C and non-treated manure were compared. The digester fed with the thermally pretreated manure had a higher methane productivity and an improved removal of the volatile solids (VS). The properties of microbial communities of both reactors were analysed. The specific methanogenic activity (SMA) test showed that both biomasses had significant activity towards hydrogen and formate, while the activity with the VFA - acetate, propionate and butyrate - was low. The kinetic parameters of the VFA conversion revealed a reduced affinity of the microbial community from the CSTR fed with thermally pre-treated manure for acetate, propionate and butyrate. The bacterial and archaeal populations identified by t-RLFP analysis of 16S rRNA genes were found to be identical in both systems. However, a change in the abundance of the species present was detected.
authors.affiliation: The Environmental Microbiology and Biotechnology Research Group, BioCentrum-DTU, Building 227, Technical University of Denmark, 2800 Lyngby, Denmark.
authors.forename: Z
authors.initials: Z
authors.lastname: Mladenovska
authors.forename: H
authors.initials: H
authors.lastname: Hartmann
authors.forename: T
authors.initials: T
authors.lastname: Kvist
authors.forename: M
authors.initials: M
authors.lastname: Sales-Cruz
authors.forename: R
authors.initials: R
authors.lastname: Gani
authors.forename: B K
authors.initials: BK
authors.lastname: Ahring
mesh_terms: D000818:Animals; D001421:Bacteria, Anaerobic / Q000378:metabolism*; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology*; D002264:Carboxylic Acids; D002417:Cattle; D006358:Hot Temperature; D007700:Kinetics; D008372:Manure / Q000382:microbiology*; D008697:Methane / Q000096:biosynthesis; D012037:Refuse Disposal / Q000379:methods*; D013552:Swine; D013696:Temperature
chemical_list: D002264:Carboxylic Acids; D008372:Manure; D008697:Methane