title: Stable isotope composition of biogas allows early warning of complete process failure as a result of ammonia inhibition in anaerobic digesters.
abstract: Four 15-L lab-scale continuous stirred tank reactors were operated under mesophilic conditions to investigate the effect of ammonia inhibition. Stable isotope fingerprinting of biogas was applied as a process monitoring tool. Ammonia inhibition was initiated by amendment of chicken manure to maize silage fed reactors. During the accumulation of ammonia, the concentration of volatile fatty acids increased while the biogas production and pH decreased. However, in one reactor, an inhibited steady state with stable gas production even at high ammonia levels was achieved, while the other reactor proceeded to complete process failure. A depletion of the δ(13)CH4 and δ(13)CO2 values preceded the process inhibition. Moreover, the stable isotope composition of biogas also forecasted the complete process failure earlier than other standard parameters. The stable isotope analyses of biogas have a potential for mechanistic insights in anaerobic processes, and may be used to pre-warn process failure under stress conditions.
authors.affiliation: Department of Bioenergy, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig, Germany.
authors.forename: Zuopeng
authors.initials: Z
authors.lastname: Lv
authors.affiliation: Department of Effect Directed Analysis, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig, Germany.
authors.forename: Meng
authors.initials: M
authors.lastname: Hu
authors.affiliation: Department of Environmental Microbiology, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig, Germany.
authors.forename: Hauke
authors.initials: H
authors.lastname: Harms
authors.affiliation: Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig, Germany.
authors.forename: Hans Hermann
authors.initials: HH
authors.lastname: Richnow
authors.affiliation: Department of Biochemical Conversion, Deutsches Biomasseforschungszentrum (DBFZ), Leipzig, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Liebetrau
authors.affiliation: Department of Bioenergy, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig, Germany. Electronic address: marcell.nikolausz@ufz.de.
authors.forename: Marcell
authors.initials: M
authors.lastname: Nikolausz
mesh_terms: D000085:Acetates / Q000032:analysis; D000641:Ammonia / Q000032:analysis*; D000693:Anaerobiosis; D000818:Animals; D056804:Biofuels / Q000032:analysis*; D019149:Bioreactors; D002245:Carbon Dioxide / Q000032:analysis; D002247:Carbon Isotopes; D002645:Chickens; D005232:Fatty Acids, Volatile / Q000032:analysis; D006859:Hydrogen; D006863:Hydrogen-Ion Concentration; D007553:Isotope Labeling; D008697:Methane / Q000032:analysis; D009584:Nitrogen / Q000032:analysis; D012820:Silage; D013997:Time Factors; D003313:Zea mays
chemical_list: D000085:Acetates; D056804:Biofuels; D002247:Carbon Isotopes; D005232:Fatty Acids, Volatile; D002245:Carbon Dioxide; D000641:Ammonia; D006859:Hydrogen; D009584:Nitrogen; D008697:Methane
keywords: Ammonia inhibition; Biogas; Process stability; Stable isotope fingerprinting