Change search
Refine search result
1 - 7 of 7
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Hansson, Mikael
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, JTI Institutet för Jordbruks- och Miljöteknik.
    Nordberg, Åke
    RISE, SP – Sveriges Tekniska Forskningsinstitut, JTI Institutet för Jordbruks- och Miljöteknik.
    Sundh, I.
    Mathisen, Berit
    RISE, SP – Sveriges Tekniska Forskningsinstitut, JTI Institutet för Jordbruks- och Miljöteknik.
    Early warning of disturbances in a laboratory-scale MSW biogas process.2002In: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 45, no 10, p. 255-260Article in journal (Refereed)
    Abstract [en]

    The use of near-infrared spectroscopy (NIR) to monitorthe dynamics of a biogas process was evaluated using multivariate data analysis. The digester was a completely stirred 8 I tank reactor fed with the organic fraction of source-sorted MSW. Intermittently the digester was overloaded with feed. Before and after overload on-line monitoring of NIR spectra and off-line analysis in the liquid and the gas phase of traditional chemical variables and microbial biomass, determined as total concentration of phospholipid fatty acids (PLFA and PLEL), were done. The dynamics that occurred due to overloading could be followed using principal component analysis of the obtained NIR-spectra. In addition, the response to changes in the digester fluid was reproducible and could be detected within five minutes, which can be considered as real-time monitoring. Selected wavelengths in the region 800-2,000 nm were used to make a PLS1 -regression with propionate. The regression resulted in a good correlation for propionate (R= 0.94 and RMSEP of 0.21 g/l in the range of 0.3-3 g/l). The results indicate the possibility to develop an early warning biogas control system based on near-infrared spectroscopy monitoring of propionate.

  • 2.
    Levén, Lotta
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, JTI Institutet för Jordbruks- och Miljöteknik.
    Wijnbladh, Erik
    SLU Swedish University of Agricultural Sciences, Sweden.
    Tuvesson, Malin
    SYVAB Himmerfjärdsverket, Sweden .
    Kragelund, Caroline
    Aalborg University, Denmark; Danish Technological Institute, Denmark.
    Hallin, Sara
    SLU Swedish University of Agricultural Sciences, Sweden.
    Control of Microthrix parvicella and sludge bulking by ozone in a full-scale WWTP2016In: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 73, no 4, p. 866-872Article in journal (Refereed)
    Abstract [en]

    Bulking and rising sludge are common problems in wastewater treatment plants (WWTPs) and are primarily caused by increased growth of filamentous bacteria such as Microthrix parvicella. It has a negative impact on sludge settling properties in activated sludge (AS) process, in addition to being responsible for foam formation. Different methods can be used to control sludge bulking. The aim of this study was to evaluate the dosage of on-site generated ozone in the recycled AS flow in a fullscale WWTP having problems caused by M. parvicella. The evaluation of the experiment was assessed by process data, microscopic analysis and microbial screening on the experimental and control line before, during and after the period of ozone dosage. The ozone treatment resulted in decreased abundance of M. parvicella and improved the settling properties, without impairing the overall process performance. Both chemical oxygen demand (COD)-and N-removal were unaffected and the dominant populations involved in nitrification, as analysed by fluorescent in situ hybridization, remained during the experimental period. When the ozone treatment was terminated, the problems with sludge bulking reappeared, indicating the importance of continuous evaluation of the process.

  • 3.
    Lindblom, Erik
    et al.
    Lund University, Sweden; Stockholm Vatten, Sweden.
    Arnell, Magnus
    RISE, SP – Sveriges Tekniska Forskningsinstitut. Lund University, Sweden.
    Flores-Alsina, Xavier
    DTU Technical University of Denmark, Denmark.
    Stenström, Fredrik
    Lund University, Sweden; VA-Ingenjörerna AB, Sweden.
    Gustavsson, D.J.I.
    VA SYD, Sweden; Sweden Water Research, Sweden.
    Yang, Jiannan
    KTH Royal Institute of Technology, Sweden; IVL Swedish Environmental Research Institute, Sweden.
    Jeppsson, Ulf
    Lund University, Sweden.
    Dynamic modelling of nitrous oxide emissions from three Swedish sludge liquor treatment systems2016In: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 73, no 4, p. 798-806Article in journal (Refereed)
    Abstract [en]

    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.

  • 4.
    Nordberg, Åke
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, JTI Institutet för Jordbruks- och Miljöteknik.
    Edström, Mats
    RISE, SP – Sveriges Tekniska Forskningsinstitut, JTI Institutet för Jordbruks- och Miljöteknik.
    Co-digestion of energy crops and the source-sorted organic fraction of municipal solid waste2005In: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 52, no 1-2, p. 217-222Article in journal (Refereed)
    Abstract [en]

    The biological and technical performance during co-digestion of energy crops and the source-sorted organic fraction of municipal solid waste has been investigated at laboratory and pilot scale. A 50:50 (TS-based) mixture of energy crops and organic waste reached a loading rate of 6.0 gVS L -1d -1 with a methane yield of 0.33-0.38 LgVS -1, while a 80:20 mixture showed elevated levels of volatile fatty acids at 5.5 gVS L -1d -1 The better performance of the 50:50 mixture can partly be explained by a better nutritional composition. Mincing the ley crop reduced viscosity and reduced problems with fibre floating and scum-blanket formation. The electricity consumed for mincing and stirring at a full-scale plant corresponds to ca 3% of the energy produced. Calculations of the costs for full-scale plants indicate that the price of the upgraded biogas has to be at least 0.078 Euro/kWh in order to balance the costs. © IWA Publishing 2005.

  • 5.
    Regmi, P.
    et al.
    Brown and Caldwell, USA.
    Miller, M.
    Brown and Caldwell, USA.
    Jimenez, J.
    Brown and Caldwell, USA.
    Stewart, H.
    Jacobs, USA.
    Johnson, B.
    Jacobs, USA.
    Amerlinck, Y.
    Ghent University, Belgium.
    Volcke, E. I. P.
    Ghent University, Belgium.
    Arnell, Magnus
    RISE - Research Institutes of Sweden, Built Environment, Energy and Circular Economy. Lund University, Sweden.
    García, P. J.
    Atkins, UK.
    Maere, T.
    Université Laval, Canada; Québec Water Research Center, Canada.
    Torfs, E.
    Université Laval, Canada; Québec Water Research Center, Canada.
    Vanrolleghem, P. A.
    Université Laval, Canada; Québec Water Research Center, Canada.
    Miletić, I.
    InCTRL Solutions Inc, Canada.
    Rieger, L.
    InCTRL Solutions Inc, Canada.
    Schraa, O.
    InCTRL Solutions Inc, Canada.
    Samstag, R.
    Bainbridge Island, USA.
    Santoro, D.
    Trojan Technologies, Canada.
    Snowling, S.
    Hydromantis ESS Inc, Canada.
    Takács, I.
    Dynamita, France.
    The future of WRRF modelling - Outlook and challenges2019In: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 79, no 1, p. 3-14Article in journal (Refereed)
    Abstract [en]

    The wastewater industry is currently facing dramatic changes, shifting away from energy-intensive wastewater treatment towards low-energy, sustainable technologies capable of achieving energy positive operation and resource recovery. The latter will shift the focus of the wastewater industry to how one could manage and extract resources from the wastewater, as opposed to the conventional paradigm of treatment. Debatable questions arise: Can the more complex models be calibrated, or will additional unknowns be introduced? After almost 30 years using well-known International Water Association (IWA) models, should the community move to other components, processes, or model structures like 'black box' models, computational fluid dynamics techniques, etc.? Can new data sources - e.g. on-line sensor data, chemical and molecular analyses, new analytical techniques, off-gas analysis - keep up with the increasing process complexity? Are different methods for data management, data reconciliation, and fault detection mature enough for coping with such a large amount of information? Are the available calibration techniques able to cope with such complex models? This paper describes the thoughts and opinions collected during the closing session of the 6th IWA/WEF Water Resource Recovery Modelling Seminar 2018. It presents a concerted and collective effort by individuals from many different sectors of the wastewater industry to offer past and present insights, as well as an outlook into the future of wastewater modelling.

  • 6. Schnurer, A.
    et al.
    Nordberg, Åke
    RISE, SP – Sveriges Tekniska Forskningsinstitut, JTI Institutet för Jordbruks- och Miljöteknik.
    Ammonia, a selective agent for methane production by syntrophic acetate oxidation at mesophilic temperature2008In: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 57, no 5, p. 735-740Article in journal (Refereed)
    Abstract [en]

    In biogas processes, methane production from acetate proceeds by either aceticlastic methanogenesis or through syntrophic acetate oxidation (SAO). In the present study, the pathway for methane production from acetate was analysed; i) during a gradual increase of the ammonia concentration (final concentration 7 g NH4+ - N/L) in a semi-continuous lab-scale anaerobic digester (4.3 L), operating at mesophilic temperature (37°C) or ii) in diluted enrichment cultures (100 ml) experiencing a gradual increase in ammonia, sodium, potassium and propionic acid. The pathway for methane formation was determined by calculating the 14CO2/14CH 4 ratio after incubating samples with 14C-2-acetate. In the anaerobic digester, as well as in the enrichment cultures, the 14CO2/14CH4 ratio clearly increased with increasing ammonium-nitrogen concentration, i.e. as the ammonia concentration increased, a shift from the aceticlastic mechanism to the syntrophic pathway occurred. The shift was very distinct and occurred as the NH4+ - N concentration rose above 3 g/l. No shift in pathway was seen during increasing concentrations of sodium, potassium or propionic acid. The shift to SAO in the biogas digester resulted in a twofold decrease in the specific gas and methane yield. © IWA Publishing 2008.

  • 7.
    Willén, Agnes
    et al.
    SLU Swedish University of Agricultural Sciences, Sweden.
    Junestedt, C.
    IVL Swedish Environmental Research Institute, Sweden.
    Rodhe, Lena
    RISE - Research Institutes of Sweden, Bioscience and Materials, Agrifood and Bioscience.
    Pell, M.
    SLU Swedish University of Agricultural Sciences, Sweden.
    Jönsson, H.
    SLU Swedish University of Agricultural Sciences, Sweden.
    Sewage sludge as fertiliser - Environmental assessment of storage and land application options2017In: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 75, no 5, p. 1034-1050Article in journal (Refereed)
    Abstract [en]

    Sewage sludge (SS) contains beneficial plant nutrients and organic matter, and therefore application of SS on agricultural land helps close nutrient loops. However, spreading operations are restricted to certain seasons and hence the SS needs to be stored. Storage and land application of SS are both potential sources of greenhouse gases and ammonia, leading to global warming, acidification and eutrophication. Covering the stored SS, treating it with urea and choosing the correct time for land application all have the potential to reduce emissions from the system. Using life cycle assessment (LCA), this study compares storage and land application options of SS in terms of global warming potential (GWP), acidification potential, eutrophication potential and primary energy use. The system with covered storage has the lowest impact of all categories. Systems with autumn application are preferable to spring application for all impact categories but, when nitrate leaching is considered, spring application is preferable in terms of eutrophication and primary energy use and, for some SS treatments, GWP. Ammonia addition reduces nitrous oxide and ammonia emissions during storage, but increases these emissions after land application. Storage duration has a large impact on GWP, while amount of chemical nitrogen fertiliser substituted has a large impact on primary energy use.

1 - 7 of 7
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
v. 2.35.7