Anaerobic biodegradability of Category 2 animal by-products: Methane potential and inoculum source

• Published in: Bioresource technology Vol. 124; pp. 276 - 282
• Main Authors: Pozdniakova, Tatiana A., Costa, José C., Santos, Ricardo J., Alves, M.M., Boaventura, Rui A.R.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-11-2012
• Subjects: Anaerobic digestion; Anaerobic treatment; Anaerobiosis; Animal by-products; Animals; Biodegradation, Environmental; Byproducts; Categories; Gompertz model; Inoculum; Inoculum source; Methane; Methane - metabolism; Plants (organisms); Sludge; Solids concentration; Wastewater treatment; Gompertz model; Solids concentration; Inoculum source; Animal by-products; Anaerobic digestion
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2012.08.022

► Methane production from animal by-products is affected by the inoculum source. ► Landfill leachate and sludge from anaerobic lagooning are good inoculum sources. ► The maximum methane production rate is 35mL CH4g−1 VSsubstrated−1. ► The biodegradability of Category 2 animal by-products is inhibited at 5% TS.
Category 2 animal by-products that need to be sterilized with steam pressure according Regulation (EC) 1774/2002 are studied. In this work, 2 sets of experiments were performed in mesophilic conditions: (i) biomethane potential determination testing 0.5%, 2.0% and 5.0% total solids (TS), using sludge from the anaerobic digester of a wastewater treatment plant as inoculum; (ii) biodegradability tests at a constant TS concentration of 2.0% and different inoculum sources (digested sludge from a wastewater treatment plant; granular sludge from an upflow anaerobic sludge blanket reactor; leachate from a municipal solid waste landfill; and sludge from the slaughterhouse wastewater treatment anaerobic lagoon) to select the more adapted inoculum to the substrate in study. The higher specific methane production was of 317mL CH4g−1 VSsubstrate for 2.0% TS. The digested sludge from the wastewater treatment plant led to the lowest lag-phase period and higher methane potential rate.