title: The impact of inocula carryover and inoculum dilution on the methane yields in batch methane potential tests.
abstract: Batch studies are used to benchmark biohydrogen potential (BHP) and biomethane potential (BMP) yields from feed substrates, digestates residues and different process configurations. This study shows that BMP yields using cellulose can be biased positively by not diluting the initial sewage sludge inoculum and the bias is independent of starting inoculum volatile solids (VS) concentration. The carryover of BHP inoculum also increased the BMP yields when using cellulose as a substrate by up to 18.8%. Furthermore it was also observed that the dilution of BMP inoculum with deionised H2O reduced methane yields from cellulose by up to 132±26 N mL-CH4 g-VS(-1). Therefore it is proposed that inoculum and standard substrate controls (as used in this study) should be included in methane batch methodologies, particularly when using a pre-fermentation stage such as dark fermentation.
authors.affiliation: Agricultural Centre for Sustainable Energy Systems (ACSES), Animal Production, Welfare and Veterinary Sciences, Harper Adams University, Newport, Shropshire TF10 8NB, United Kingdom. Electronic address: mreilly@harper-adams.ac.uk.
authors.forename: Matthew
authors.initials: M
authors.lastname: Reilly
authors.affiliation: Sustainable Environment Research Centre (SERC), Faculty of Computing, Engineering and Science, University Of South Wales, Upper Glyntaff, Pontypridd CF37 1BD, United Kingdom.
authors.forename: Richard
authors.initials: R
authors.lastname: Dinsdale
authors.affiliation: Sustainable Environment Research Centre (SERC), Faculty of Computing, Engineering and Science, University Of South Wales, Upper Glyntaff, Pontypridd CF37 1BD, United Kingdom.
authors.forename: Alan
authors.initials: A
authors.lastname: Guwy
mesh_terms: D061249:Batch Cell Culture Techniques; D001709:Biotechnology / Q000379:methods*; D002482:Cellulose / Q000378:metabolism; D005285:Fermentation; D006859:Hydrogen / Q000378:metabolism; D008697:Methane / Q000096:biosynthesis*; D012722:Sewage / Q000382:microbiology*
chemical_list: D012722:Sewage; D006859:Hydrogen; D002482:Cellulose; D008697:Methane
keywords: Batch studies; Biohydrogen; Biomethane; Dark fermentation; Two-stage anaerobic digestion