Indigenous microbial capability in solid manure residues to start-up solid-phase anaerobic digesters

Yap, S. D. and Astals, S. and Jensen, P. D. and Batstone, D. J. and Tait, S. (2017) Indigenous microbial capability in solid manure residues to start-up solid-phase anaerobic digesters. Waste Management, 64. pp. 79-87. ISSN 0956-053X


Batch solid-phase anaerobic digestion is a technology for sustainable on-farm treatment of solid residues, but is an emerging technology that is yet to be optimised with respect to start-up and inoculation. In the present study, spent bedding from two piggeries (site A and B) were batch digested at total solids (TS) concentration of 5,10 and 20% at mesophilic (37 degrees C) and thermophilic (55 degrees C) temperatures, without adding an external inoculum. The results showed that the indigenous microbial community present in spent bedding was able to recover the full methane potential of the bedding (140 +/- 5 and 227 +/- 6 L CH4 kgVS(Fed)(-1) for site A and B, respectively), but longer treatment times were required than for digestion with an added external inoculum. Nonetheless, at high solid loadings (i.e. TS level > 10%), the digestion performance was affected by chemical inhibition due to ammonia and/or humic acid. Thermophilic temperatures did not influence digestion performance but did increase start-up failure risk. Further, inoculation of residues from the batch digestion to subsequent batch enhanced start-up and achieved full methane potential recovery of the bedding. Inoculation with liquid residue (leachate) was preferred over a solid residue, to preserve treatment capacity for fresh substrate. Overall, the study highlighted that indigenous microbial community in the solid manure residue was capable of recovering full methane potential and that solid-phase digestion was ultimately limited by chemical inhibition rather than lack of suitable microbial community.

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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Files associated with this item cannot be displayed due to copyright restrictions.
Faculty / Department / School: Current - Faculty of Health, Engineering and Sciences - School of Agricultural, Computational and Environmental Sciences
Date Deposited: 08 Apr 2019 02:46
Last Modified: 18 Apr 2019 02:06
Uncontrolled Keywords: anaerobic digestion, microbial community, manure, straw, inoculum, biological inhibition
Fields of Research : 09 Engineering > 0907 Environmental Engineering > 090703 Environmental Technologies
Socio-Economic Objective: E Expanding Knowledge > 97 Expanding Knowledge > 970105 Expanding Knowledge in the Environmental Sciences
Identification Number or DOI: 10.1016/j.wasman.2017.02.031

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