Effect of Endogenous Methane Production: A Step Forward in the Validation of Biochemical Methane Potential (BMP) Tests

João V. Oliveira, José C. Costa, Ana J. Cavaleiro, Maria Alcina Pereira and Maria Madalena Alves
Additional contact information
João V. Oliveira: CEB—Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
José C. Costa: CEB—Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
Ana J. Cavaleiro: CEB—Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
Maria Alcina Pereira: CEB—Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
Maria Madalena Alves: CEB—Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal

Energies, 2022, vol. 15, issue 13, 1-16

Abstract: This work evaluates the influence of the inoculum type, the pre-consumption of the residual substrate and the ratio of blanks’ headspace volume to working volume (Hv Wv −1 , 0.6 to 10) on Biochemical Methane Potential (BMP) measurements when methane is monitored by gas chromatography. Different inocula were tested: digested sewage sludge—DSS, granular sludge—GS and fresh dairy manure—DM. Microcrystalline cellulose was used as the substrate. BMP surpassed the maximum theoretical value (BMP max = 414 L kg −1 ) when methane produced in the blanks was not discounted, showing that degassing cannot stand alone as an alternative to the procedure of discounting the inoculum’s background production. Still, when the residual substrate concentration is high (e.g., in DM), degassing is mandatory because methane produced from its digestion will conceal the methane produced from the substrate in the BMP determination. For inocula with a low residual substrate (e.g., GS), short degassing periods are recommended in order to avoid detrimental effects on methanogenic activity. For moderate residual substrate concentrations (e.g., DSS), BMP values closer to BMP max (90–97%) were achieved after degassing and discounting the blanks with lower Hv Wv −1 . For higher Hv ∙ Wv −1 , less accurate quantification occurred, likely due to error propagation. Proper inoculum pre-incubation time and discounting the methane production from blanks with low Hv Wv −1 (adjusted according to the estimated background methane) are essential for accurate BMP determinations.

Keywords: anaerobic biodegradability; biomethane potential; blank assays; degassing; inoculum; digested sewage sludge; granular sludge; dairy manure; residual substrate (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2022
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (1)

Downloads: (external link)
https://www.mdpi.com/1996-1073/15/13/4696/pdf (application/pdf)
https://www.mdpi.com/1996-1073/15/13/4696/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jeners:v:15:y:2022:i:13:p:4696-:d:848588

Access Statistics for this article

Energies is currently edited by Ms. Agatha Cao

More articles in Energies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().