Methane production yields achieved through the anaerobic digestion of mechanically sorted-organic fractions of municipal solid waste (MS-OFMSW) are generally lower than those obtained with source sorted-fractions (Hartmann and Ahring, 2006), but MS-OFMSW biomethanization can be enhanced through the acclimatization of a microbial population. An anaerobic consortium capable of efficiently converting the organic fraction of MS-OFMSW into methane was obtained through a dedicated enrichment procedure in a 0.36 L up-flow anaerobic recirculated reactor. The system was initially filled with cattle manure (2.2% VSS, 6.2 g L-1 COD), an effective co-substrate for biomethanization of MS-OFMSW (Bertin et al., 2008); after a short batch working period, it was fed with MS-OFMSW according to a semi-continuous scheme, i.e. through successive short-time batch processes. In particular, at the beginning of each 56 hours batch cycle, 11mL of the processed waste were collected from the reactor, an equal volume of the waste (2.1% w/w VSS, 57.5 g L-1 COD) was then added by replacing part of the manure with MS-OFMSW which after 5 months theoretically constituted more than 99% of the reaction volume. The COD measured at the end of each period slowly decreased from 7.1 to 4.4 g L-1 and more than 90% of the overall COD fed during the experiment was depleted. Methanogenesis yield gradually increased up to 0.35 L g-1 depleted COD throughout the process. Molecular analysis of the microbial consortium indicated that while Archeal population was unaffected by sequencing fed-batch enrichment on MS-OFMSW, several hydrolytic and acidogenic Firmicutes and Bacteroidetes were enriched concomitantly to the observed increase of the biomethanization. The abovementioned bacterial species are probably essential for the effective biomethanization of MS-OFMSW carried out by the acclimated microbial community obtained in this study. Hartmann H. and Ahring B.K. (2006). Wat. Sci. Technol. 53(8):7-22. Bertin et al. (2008). Wat. Sci. Technol. 58(9):1735-1742
A. Negroni, L. Bertin, C. Bettini, G. Zanaroli, S. Fraraccio, F. Fava (2011). Obtainment of a microbial consortium able to perform an effective biomethanization of a mechanically-sorted Organic fraction of municipal solid waste through a semicontinuous culture enrichment procedure. s.n.
Obtainment of a microbial consortium able to perform an effective biomethanization of a mechanically-sorted Organic fraction of municipal solid waste through a semicontinuous culture enrichment procedure
NEGRONI, ANDREA;BERTIN, LORENZO;BETTINI, CRISTINA;ZANAROLI, GIULIO;FRARACCIO, SERENA;FAVA, FABIO
2011
Abstract
Methane production yields achieved through the anaerobic digestion of mechanically sorted-organic fractions of municipal solid waste (MS-OFMSW) are generally lower than those obtained with source sorted-fractions (Hartmann and Ahring, 2006), but MS-OFMSW biomethanization can be enhanced through the acclimatization of a microbial population. An anaerobic consortium capable of efficiently converting the organic fraction of MS-OFMSW into methane was obtained through a dedicated enrichment procedure in a 0.36 L up-flow anaerobic recirculated reactor. The system was initially filled with cattle manure (2.2% VSS, 6.2 g L-1 COD), an effective co-substrate for biomethanization of MS-OFMSW (Bertin et al., 2008); after a short batch working period, it was fed with MS-OFMSW according to a semi-continuous scheme, i.e. through successive short-time batch processes. In particular, at the beginning of each 56 hours batch cycle, 11mL of the processed waste were collected from the reactor, an equal volume of the waste (2.1% w/w VSS, 57.5 g L-1 COD) was then added by replacing part of the manure with MS-OFMSW which after 5 months theoretically constituted more than 99% of the reaction volume. The COD measured at the end of each period slowly decreased from 7.1 to 4.4 g L-1 and more than 90% of the overall COD fed during the experiment was depleted. Methanogenesis yield gradually increased up to 0.35 L g-1 depleted COD throughout the process. Molecular analysis of the microbial consortium indicated that while Archeal population was unaffected by sequencing fed-batch enrichment on MS-OFMSW, several hydrolytic and acidogenic Firmicutes and Bacteroidetes were enriched concomitantly to the observed increase of the biomethanization. The abovementioned bacterial species are probably essential for the effective biomethanization of MS-OFMSW carried out by the acclimated microbial community obtained in this study. Hartmann H. and Ahring B.K. (2006). Wat. Sci. Technol. 53(8):7-22. Bertin et al. (2008). Wat. Sci. Technol. 58(9):1735-1742I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
