title: Recovery of failed solid-state anaerobic digesters.
abstract: This study examined the performance of three methods for recovering failed solid-state anaerobic digesters. The 9-L digesters, which were fed with corn stover, failed at a feedstock/inoculum (F/I) ratio of 10 with negligible methane yields. To recover the systems, inoculum was added to bring the F/I ratio to 4. Inoculum was either added to the top of a failed digester, injected into it, or well-mixed with the existing feedstock. Digesters using top-addition and injection methods quickly resumed and achieved peak yields in 10days, while digesters using well-mixed method recovered slowly but showed 50% higher peak yields. Overall, these methods recovered 30-40% methane from failed digesters. The well-mixed method showed the highest methane yield, followed by the injection and top-addition methods. Recovered digesters outperformed digesters had a constant F/I ratio of 4. Slow mass transfer and slow growth of microbes were believed to be the major limiting factors for recovery.
authors.affiliation: Department of Health Sciences, Illinois State University, 324 Felmley Hall, Normal, IL 61790, USA. Electronic address: lyang@ilstu.edu.
authors.forename: Liangcheng
authors.initials: L
authors.lastname: Yang
authors.affiliation: Department of Food, Agricultural and Biological Engineering, The Ohio State University/Ohio Agricultural Research and Development Center, 1680 Madison Ave., Wooster, OH 44691-4096, USA.
authors.forename: Xumeng
authors.initials: X
authors.lastname: Ge
authors.affiliation: Department of Food, Agricultural and Biological Engineering, The Ohio State University/Ohio Agricultural Research and Development Center, 1680 Madison Ave., Wooster, OH 44691-4096, USA. Electronic address: li.851@osu.edu.
authors.forename: Yebo
authors.initials: Y
authors.lastname: Li
mesh_terms: D000693:Anaerobiosis; D019149:Bioreactors; D008697:Methane / Q000032:analysis; D003313:Zea mays
chemical_list: D008697:Methane
keywords: Digester failure; Mass transfer; Recovery; Solid-state anaerobic digestion