title: Dry anaerobic digestion of high solids content dairy manure at high organic loading rates in psychrophilic sequence batch reactor.
abstract: Cow manure with bedding is renewable organic biomass available around the year on dairy farms. Developing efficient and cost-effective psychrophilic dry anaerobic digestion (PDAD) processes could contribute to solving farm-related environmental, energy, and manure management problems in cold-climate regions. This study was to increase the organic loading rate (OLR), fed to a novel psychrophilic (20 °C) dry anaerobic digestion of 27% total solid dairy manure (cow feces and wheat straw) in sequence batch reactor (PDAD-SBR), by 133 to 160%. The PDAD-SBR process operated at treatment cycle length of 21 days and OLR of 7.0 and 8.0 g total chemical oxygen demand (TCOD) kg(-1) inoculum day(-1) (5.2 ± 0.1 and 5.8 ± 0.0 g volatile solids (VS) kg(-1) inoculum day(-1)) for four successive cycles (84 days) produced average specific methane yields (SMYs) of 147.1 ± 17.2 and 143.2 ± 11.7 normalized liters (NL) CH4 kg(-1) VS fed, respectively. PDAD of cow feces and wheat straw is possible with VS-based inoculum-to-substrate ratio of 1.45 at OLR of 8.0 g TCOD kg(-1) inoculum day(-1). Hydrolysis was the limiting step reaction. The VS removal averaged around 57.4 ± 0.5 and 60.5 ± 5.7% at OLR 7.0 and 8.0 g TCOD kg(-1) inoculum day(-1), respectively.
authors.affiliation: Dairy and Swine Research and Development Centre, Agriculture and Agri-Food Canada, Sherbrooke, QC, J1M 0C8, Canada.
authors.forename: Daniel I
authors.initials: DI
authors.lastname: Massé
authors.forename: Noori M Cata
authors.initials: NM
authors.lastname: Saady
mesh_terms: D000693:Anaerobiosis; D000818:Animals; D019149:Bioreactors; D002417:Cattle; D004063:Digestion; D005243:Feces / Q000737:chemistry; D008372:Manure / Q000032:analysis*; D008697:Methane / Q000032:analysis; D018547:Plant Stems / Q000737:chemistry; D014908:Triticum / Q000737:chemistry
chemical_list: D008372:Manure; D008697:Methane