title: Carbon turnover and ammonia emissions during composting of biowaste at different temperatures.
abstract: The effects of different process temperatures (40, 55, and 67 degrees C) during composting of source-separated household waste were studied in a 200 L compost reactor at an oxygen concentration of 16%. The overall decomposition measured as carbon mineralization, decomposition of different carbon constituents, and the dynamics of nitrogen mineralization and the microbial community, are reported. Ammonia emissions at 67 degrees C were more than double those at lower temperatures, and they were lowest at 40 degrees C. The decomposition rate, measured as CO2 emission, was highest at 55 degrees C. Decomposition of crude fat was slower at 40 degrees C than at 55 and 67 degrees C. The peak in microbial biomass was largest in the run at 40 degrees C, where substantial differences were seen in the microbial community structure and succession compared to thermophilic temperatures. Biowaste composting can be optimized to obtain both a high decomposition rate and low ammonia emissions by controlling the process at about 55 degrees C in the initial, high-rate stage. To reduce ammonia emissions it seems worthwhile to reduce the temperature after an initial high-temperature stage.
authors.affiliation: Department of Soil Sciences, Swedish University of Agricultural Sciences, P.O. Box 7014, SE-750 07 Uppsala, Sweden.
authors.forename: Ylva
authors.initials: Y
authors.lastname: Eklind
authors.forename: Cecilia
authors.initials: C
authors.lastname: Sundberg
authors.forename: Sven
authors.initials: S
authors.lastname: Smårs
authors.forename: Kristin
authors.initials: K
authors.lastname: Steger
authors.forename: Ingvar
authors.initials: I
authors.lastname: Sundh
authors.forename: Holger
authors.initials: H
authors.lastname: Kirchmann
authors.forename: Håkan
authors.initials: H
authors.lastname: Jönsson
mesh_terms: D000641:Ammonia / Q000032:analysis* / Q000378:metabolism; D018533:Biomass; D019149:Bioreactors; D002244:Carbon / Q000378:metabolism*; D002245:Carbon Dioxide / Q000032:analysis / Q000378:metabolism; D005227:Fatty Acids / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D009584:Nitrogen / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D012987:Soil; D012988:Soil Microbiology; D013696:Temperature; D013997:Time Factors; D018505:Waste Management
chemical_list: D005227:Fatty Acids; D012987:Soil; D002245:Carbon Dioxide; D002244:Carbon; D000641:Ammonia; D009584:Nitrogen; D010100:Oxygen