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

Journal Article · Sat Aug 15 04:00:00 EDT 2015 · Waste Management

DOI:https://doi.org/10.1016/J.WASMAN.2015.02.038· OSTI ID:22472530

Tsutsui, Hirofumi ^[1]; Fujiwara, Taku ^[1]; Inoue, Daisuke ^[2]; Ito, Ryusei ^[3]; Matsukawa, Kazutsugu ^[4]; Funamizu, Naoyuki ^[3]

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1. Research and Education Faculty, Natural Sciences Cluster, Agriculture Unit, Kochi University, B200 Monobe, Nankoku, Kochi (Japan)
2. Department of Health Science, School of Allied Health Sciences, Kitasato University, 1-15-1 Kitasato, Sagamihara-Minami, Kanagawa (Japan)
3. Department of Environmental Engineering, Graduate School of Engineering, Hokkaido University, Kita-13, Nishi-8, Kita-ku, Sapporo, Hokkaido (Japan)
4. Research and Education Faculty, Multidisciplinary Science Cluster, Life and Environmental Medicine Science Unit, Kochi University, B200 Monobe, Nankoku, Kochi (Japan)

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.

• OSTI ID: 22472530
• Journal Information: Waste Management, Journal Name: Waste Management Vol. 42; ISSN WAMAE2; ISSN 0956-053X
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
AMMONIA
CARBON DIOXIDE
COMPOSTING
CONVERSION RATIO
MASS BALANCE
NITRIFICATION
NITROUS OXIDE
ORGANIC COMPOUNDS