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Title: Relationship between respiratory quotient, nitrification, and nitrous oxide emissions in a forced aerated composting process

Highlights: • RQ can be an indicator of N{sub 2}O emission in forced aerated composting process. • Emission of N{sub 2}O with nitrification was observed with RQ decrease. • Mass balances demonstrated the RQ decrease was caused by nitrification. • Conversion ratio of oxidized ammonia and total N to N{sub 2}O were ∼2.7%. - Abstract: We assessed the relationship between respiratory quotient (RQ) and nitrification and nitrous oxide (N{sub 2}O) emission in forced aerated composting using lab-scale reactors. Relatively high RQ values from degradation of readily degradable organics initially occurred. RQ then stabilized at slightly lower values, then decreased. Continuous emission of N{sub 2}O was observed during the RQ decrease. Correlation between nitrification and N{sub 2}O emission shows that the latter was triggered by nitrification. Mass balances demonstrated that the O{sub 2} consumption of nitrification (∼24.8 mmol) was slightly higher than that of CO{sub 2} emission (∼20.0 mmol), indicating that the RQ decrease was caused by the occurrence of nitrification. Results indicate that RQ is a useful index, which not only reflects the bioavailability of organics but also predicts the occurrence of nitrification and N{sub 2}O emission in forced aerated composting.
Authors:
 [1] ;  [2] ;  [1] ;  [2] ;  [3] ;  [2] ;  [4] ;  [2] ;  [5] ;  [2] ;  [4] ;  [2]
  1. Research and Education Faculty, Natural Sciences Cluster, Agriculture Unit, Kochi University, B200 Monobe, Nankoku, Kochi (Japan)
  2. (Japan)
  3. Department of Health Science, School of Allied Health Sciences, Kitasato University, 1-15-1 Kitasato, Sagamihara-Minami, Kanagawa (Japan)
  4. Department of Environmental Engineering, Graduate School of Engineering, Hokkaido University, Kita-13, Nishi-8, Kita-ku, Sapporo, Hokkaido (Japan)
  5. Research and Education Faculty, Multidisciplinary Science Cluster, Life and Environmental Medicine Science Unit, Kochi University, B200 Monobe, Nankoku, Kochi (Japan)
Publication Date:
OSTI Identifier:
22472530
Resource Type:
Journal Article
Resource Relation:
Journal Name: Waste Management; Journal Volume: 42; Other Information: Copyright (c) 2015 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; AMMONIA; CARBON DIOXIDE; COMPOSTING; CONVERSION RATIO; MASS BALANCE; NITRIFICATION; NITROUS OXIDE; ORGANIC COMPOUNDS