title: Dynamic modelling of nitrous oxide emissions from three Swedish sludge liquor treatment systems.
abstract: The objective of this paper is to model the dynamics and validate the results of nitrous oxide (N2O) emissions from three Swedish nitrifying/denitrifying, nitritation and anammox systems treating real anaerobic digester sludge liquor. The Activated Sludge Model No. 1 is extended to describe N2O production by both heterotrophic and autotrophic denitrification. In addition, mass transfer equations are implemented to characterize the dynamics of N2O in the water and the gas phases. The biochemical model is simulated and validated for two hydraulic patterns: (1) a sequencing batch reactor; and (2) a moving-bed biofilm reactor. Results show that the calibrated model is partly capable of reproducing the behaviour of N2O as well as the nitritation/nitrification/denitrification dynamics. However, the results emphasize that additional work is required before N2O emissions from sludge liquor treatment plants can be generally predicted with high certainty by simulations. Continued efforts should focus on determining the switching conditions for different N2O formation pathways and, if full-scale data are used, more detailed modelling of the measurement devices might improve the conclusions that can be drawn.
authors.affiliation: Division of Industrial Electrical Engineering and Automation (IEA), Department of Biomedical Engineering, Lund University, PO Box 118, SE-221 00 Lund, Sweden; Stockholm Vatten, SE-106 36 Stockholm, Sweden E-mail: erik.lindblom@stockholmvatten.se.
authors.forename: E
authors.initials: E
authors.lastname: Lindblom
authors.affiliation: Division of Industrial Electrical Engineering and Automation (IEA), Department of Biomedical Engineering, Lund University, PO Box 118, SE-221 00 Lund, Sweden; SP Technical Research Institute of Sweden, Gjuterigatan 1D, SE-582 73 Linköping, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Arnell
authors.affiliation: Department of Chemical and Biochemical Engineering, Technical University of Denmark, DK-2800 Lyngby, Denmark.
authors.forename: X
authors.initials: X
authors.lastname: Flores-Alsina
authors.affiliation: Water and Environmental Engineering, Department of Chemical Engineering, Lund University, PO Box 118, SE-221 00 Lund, Sweden and VA-Ingenjörerna AB, Trädgårdsgatan 12, SE-702 12 Örebro, Sweden.
authors.forename: F
authors.initials: F
authors.lastname: Stenström
authors.affiliation: VA SYD, PO Box 191, SE-201 21 Malmö, Sweden and Sweden Water Research, Ideon Science Park, Scheelevägen 15, SE-223 70 Lund, Sweden.
authors.forename: D J I
authors.initials: DJ
authors.lastname: Gustavsson
authors.affiliation: Department of Sustainable Development, Environmental Science and Engineering, Royal Institute of Technology (KTH), Teknikringen 76, SE-100 44, Stockholm, Sweden and Swedish Environmental Research Institute (IVL), Valhallavägen 81, SE-100 31, Stockholm, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Yang
authors.affiliation: Division of Industrial Electrical Engineering and Automation (IEA), Department of Biomedical Engineering, Lund University, PO Box 118, SE-221 00 Lund, Sweden.
authors.forename: U
authors.initials: U
authors.lastname: Jeppsson
mesh_terms: D058440:Denitrification; D008962:Models, Theoretical; D058465:Nitrification; D009609:Nitrous Oxide / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry*; D013548:Sweden; D018508:Water Purification / Q000295:instrumentation*
chemical_list: D012722:Sewage; D009609:Nitrous Oxide