Influence of ferric oxyhydroxide addition on biomethanation of waste activated sludge in a continuous reactor

• Published in: Bioresource technology 2014-08, Vol.166, p.596-601
• Main Authors: Baek, Gahyun, Kim, Jaai, Lee, Changsoo
• Format: Article
• Language: English
• Subjects: Applied sciences; Bacteria; Bacteria, Anaerobic - classification; Bacteria, Anaerobic - metabolism; Biofuel production; Biological and medical sciences; Biological treatment of sewage sludges and wastes; Biomethanation; Bioreactors; Biotechnology; Communities; Consortia; Energy; Environment and pollution; Exact sciences and technology; Ferric Compounds - chemistry; Ferric oxyhydroxide; Fundamental and applied biological sciences. Psychology; Industrial applications and implications. Economical aspects; Iron oxyhydroxide; Iron-reducing bacteria; Methane; Methane - chemistry; Microbial community structure; Pollution; Reactors; Sewage - chemistry; Sewage - microbiology; Sludge; Waste activated sludge; Waste Management - methods; Wastes
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2014.05.052

•Effects of enhanced IRB activity on anaerobic digestion of WAS were studied.•Raised IRB activity by biostimulation/augmentation led to enhanced biomethanation.•Acinetobacter- and Spirochaetales-related populations were likely the dominant IRBs. This study investigated the potential of enhancing the activity of iron-reducing bacteria (IRBs) to increase the biomethanation rate of waste activate sludge (WAS). The effects of biostimulation by ferric oxyhydroxide (Phase 2) and bioaugmentation with an enriched IRB consortium (Phase 3) were examined in a continuous anaerobic reactor treating WAS. Compared to the control operation (Phase 1), significant rises in methane yield (10.8–59.4%) and production rate (24.5–52.9%) were demonstrated by the biostimulation and bioaugmentation treatments. Visible structural changes were observed in bacterial community with the phases while not in archaeal community. Acinetobacter- and Spirochaetales-related populations were likely the major players driving anaerobic iron respiration and thus leading to enhanced biomethanation performance, in Phases 2 and 3, respectively. Our results suggest an interesting new potential for enhancing biomethanation of WAS.