Bioaugmentation for improved recovery of anaerobic digesters after toxicant exposure

Abstract

Abstract:Bioaugmentation was investigated as a method to decrease the recovery period of anaerobic digesters exposed to a transient toxic event. Two sets of laboratory-scale digesters (SRT = 10 days, OLR = 2 g COD/Lday),started with inoculum from a digester stabilizing synthetic municipal wastewater solids (MW) and synthetic industrial wastewater (WW), respectively, were transiently exposed to the model toxicant, oxygen.Bioaugmented digesters received 1.2 g VSS/L-day of an H2-utilizing culture NOT THE PUBLISHED VERSION; this is the author's final, peer-reviewed manuscript. The published version may be accessed by following the link in the citation at the bottom of the page.Water Research, Vol. 44, No. 12 (June 2010): pg. 3555-3564. DOI. This article is © Elsevier and permission has been granted for this version to appear in e-Publications@Marquette. Elsevier does not grant permission for this article to be further copied/distributed or hosted elsewhere without the express permission from Elsevier. 2for which the archaeal community was analyzed. Soon after oxygen exposure, the bioaugmented digesters produced 25-60% more methane than nonbioaugmented controls (p < 0.05). One set of digesters produced lingering high propionate concentrations, and bioaugmentation resulted in significantly shorter recovery periods. The second set of digesters did not display lingering propionate, and bioaugmented digesters recovered at the same time as nonbioaugmented controls. The difference in the effect of bioaugmentation on recovery may be due to differences between microbial communities of the digester inocula originally employed. In conclusion, bioaugmentation with an H2-utilizing culture is a potential tool to decrease the recovery period, decrease propionate concentration, and increase biogas production of some anaerobic digesters after a toxic event. Digesters already containing rapidly adaptable microbial communities may not benefit from bioaugmentation, whereas other digesters with poorly adaptable microbial communities may benefit greatly.

Pretreatment and Anaerobic Co-digestion of Selected PHB and PLA Bioplastics

“…Total solids and VS concentration and COD were measured by standard methods (APHA, AWWA, WEF, 1999). VFA concentrations were determined by gas chromatography flame ionization detection (GC-FID) after samples were centrifuged, supernatant filtered through 0.45 µm syringe-tip filter, and acidified with phosphoric acid (Schauer-Gimenez et al, 2010). Since accurate bioplastic COD analysis was not achievable, the bioplastics ThOD values were calculated based on the bioplastic mass and molecular structure, with ratios of 1.67 g ThOD/g PHB and 1.33 g ThOD/g PLA.…”

The dominant acetate degradation pathway/methanogenic composition in full-scale anaerobic digesters operating under different ammonia levels

“…Thus, based also on findings in previous studies (Fotidis et al 2013a), it is possible to introduce SAO-HM pathway in a digester by controlling the ammonia levels as long as a ''critical biomass'' of ammonia-tolerant fast-growing methanogenic consortium is present. If ammonia-tolerant consortia are not present, a technical approach to overcome ammonia inhibitions could be bioaugmentation (Schauer-Gimenez et al 2010) of ammonia-tolerant methanogenic consortia in anaerobic digesters operating under high ammonia levels. Unfortunately, this has not been demonstrated yet.…”

Presence of a Novel Methanogenic Archaeal Lineage in Anaerobic Digesters Inferred from <I>mcrA</I> and 16S rRNA Gene Phylogenetic Analyses

“…Chouari et al (2005) reported that the enrichment of WCHA1-57 (ARC I) phylotypes in cultivations using formate or H 2 /CO 2 as substrates, which are typical substrates for methanogenic archaea, although the methane production of the enrichments was not checked in the literature. In addition, many WCHA1-57-related 16S rRNA gene sequences have been retrieved from anaerobic digesters (Chouari et al, 2005;Steinberg and Regan, 2008;Rivière et al, 2009;Schauer-Gimenez et al, 2010). In some anaerobic digesters treating municipal sewage sludge, the WCHA1-57 phylotype population represented one of the predominant archaeal components, and the relative clonal abundance was > 70% in the archaeal clone libraries (Chouari et al, 2005;Rivière et al, 2009).…”