title: Start-up of a sequential dry anaerobic digestion of paunch under psychrophilic and mesophilic temperatures.
abstract: The present laboratory study evaluated the sequential leach bed dry anaerobic digestion (DAD) of paunch under psychrophilic (22°C) and mesophilic (40°C) temperatures. Three leach bed reactors were operated under the mesophilic temperature in sequence at a solid retention time (SRT) of 40d with a new batch started 27d into the run of the previous one. A total of six batches were operated for 135d. The results showed that the mesophilic DAD of paunch was efficient, reaching methane yields of 126.9-212.1mLg-1volatile solid (VS) and a VS reduction of 32.9-55.5%. The average daily methane production rate increased from 334.3mLd-1to 571.4mLd-1and 825.7mLd-1when one, two and three leach bed reactors were in operation, respectively. The psychrophilic DAD of paunch was operated under a SRT of 100d and a total of three batches were performed in sequence for 300d with each batch starting after completion of the previous one. Improvements in the methane yield from 93.9 to 107.3 and 148.3mLg-1VS and VS reductions of 24.8, 30.2 and 38.6% were obtained in the consecutive runs, indicating the adaptation of anaerobic microbes from mesophilic to psychrophilic temperatures. In addition, it took three runs for anaerobic microbes to reduce the volatile fatty acid accumulation observed in the first and second trials. This study demonstrates the potential of renewable energy recovery from paunch under psychrophilic and mesophilic temperatures.
authors.affiliation: Agriculture and Agri-Food Canada, Lethbridge Research and Development Centre, 5403 1st Ave S., Lethbridge, Canada.
authors.forename: Valentine Nkongndem
authors.initials: VN
authors.lastname: Nkemka
authors.affiliation: Agriculture and Agri-Food Canada, Lethbridge Research and Development Centre, 5403 1st Ave S., Lethbridge, Canada. Electronic address: xiying.hao@agr.gc.ca.
authors.forename: Xiying
authors.initials: X
authors.lastname: Hao
mesh_terms: D000693:Anaerobiosis; D019149:Bioreactors; D008697:Methane; D013696:Temperature
chemical_list: D008697:Methane
keywords: Chemical oxygen demand; Leach bed reactor; Methane yield; Slaughterhouse waste; Volatile fatty acid