Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2009
Forfattere
Atle HaugeSammendrag
Rapporten oppsummerer tiltaksgjennomføring fra tiltakspakke II pr. august 2009. 4 tiltak var ikke gjennomført; utvidelse av fangdam øverst og nederst, overflatekum på lukkingsanlegg på Holleby, sedimentasjonskammer langs veien sør for Holleby og vegetasjonssone over lukkingsanlegg i Sjørenbekkens østre løp.En foreslår følgende nye tiltak: Utvidelse av fangdammen i innløpet med ekstra sedimentasjonskammer, omlegging av lukkinger og drensledninger til dammens innløp, Leca-filter i midten av dammen etter sedimentasjonskamrene, fangdam/flomdam langs Hollebyveien, ny fangdam nederst på søndre jorde på Grønli, flomdam i Sjørenbekkens østre løp, 3 kumdammer rundt overflatekummer og faste grasdekte vannveier over lukkingsanlegg som munner ut i fangdammen.
Forfattere
Bent Braskerud Atle HaugeSammendrag
This report describes how small constructed wetlands (CWs) of approximately 0.1 % of the watershed area can contribute to cleaner waterways. The report summarises more than 10 years experience of investigation and construction of wetlands in Norway, where agricultural authorities finance the construction of wetlands. Investigations show that the average retention in the different wetlands was 45-75 % for soil particles, and 21-44 % for phosphorus (P). The retention of particles and P tends to increase with runoff due to erosion processes in the watershed. Higher constructed wetland (CW) effectiveness than expected is a combined effect of (i) clay particles entering wetlands as aggregates with higher sedimentation velocity than single particles, (ii) shallow depth which gives shorter particle settling distance, and (iii) vegetation cover preventing resuspension of sediment. The use of mineral filters can increase the P-retention performance under low runoff situations. Due to high hydraulic loads the redox potential in the outlet water indicated aerobic conditions. As a result the redox-sensitive P in the wetland sediment is conserved providing a sufficient amount of water flows through the CW. Small CWs have a minor effect on nitrogen (N) retention (3-15 %) due to the short detention time. Use of organic filters can increase the N-retention performance. However, these filters will decrease the P-retention, because the water becomes anoxic. Wetlands can reduce the pesticide content in water. The effect is correlated to the physical and chemical behaviour of the pesticide. As a result, retention could vary from 0 to 67 %. To summarise, the most important factor for pollution retention performance in small wetlands is properties of the watershed itself (such as type of agriculture, soil type, erosion rates, aggregate stability etc). Important design criteria are shallow (max. 0.5 m) and vegetated wetland filters, and location close to the source of pollution.
Forfattere
Douwe Hoornstra Tommy Nesbakk Espen Govasmark Mirja Salkinoja-SalonenSammendrag
Background: Anaerobic digestion in a biogas plant (BGP) is an alternative way to handle organic household waste. There is an increasing interest in BGPs using municipal food waste as energy source for producing gas, mainly methane. The waste product from a BGP is digestate, which may be used as a fertiliser in organic agriculture. The digestate can be separated into a solid and a liquid fraction by centrifugation. Objective: To assess the hygienic risk of toxigenic bacteria in the liquid fraction of the digestate (~2 % d.w.) from a BGP using municipal food waste as an energy source, focusing on heat stable toxin producing Bacillus cereus. Method: The digestate was sampled monthly from a BGP from May 2008 to February 2009. The potential for cereulide production in the digestate was measured by quantitative PCR using primers targeted at B. cereus group (Hansen et al. 2001) and the peptide synthetase gene specific for cereulide (cesB gene; Ehling-Schulz et al 2004), and it was searched for cultivable isolates of toxigenic B. cereus. Result: The digestate contained an average of 104 copies of B. cereus genome and 103 to 104 cesB gene copies per ml. The digestate contained 0.5 to 10 × 106 viable bacteria per ml of which 1 % were heat stable spores. Culturable presumptive B. cereus was isolated in 9 out of 10 samples, averaging 102 CFU per ml. Conclusion: 1) Analysis of DNA showed that the raw materials used for the biogas production contained B. cereus. A significant portion of the B. cereus genomes possessed the cesB gene. 2) Approximately 1 % of the heat stable spores represented B. cereus. The content of viable B. cereus in the liquid fraction of the digestate was within the limits acceptable for foods.
Forfattere
Jessica Stäb Espen Govasmark Bertram Kuch Jörg MetzgerSammendrag
Det er ikke registrert sammendrag
Forfattere
Espen Govasmark Anicke Brandt-KjelsenSammendrag
Det er ikke registrert sammendrag
Forfattere
Espen GovasmarkSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Dette oppdraget utføres i samarbeid med NIVA; Rapport finnes i NIVA"s rapportarkiv; www.niva.no. Rapporten gir oversikt over Biologiske og vannkjemiske data innsamlet i 2008 i vassdrag på Romerike.
Forfattere
Anicke Brandt-Kjelsen Espen Govasmark Brit SalbuSammendrag
Det er ikke registrert sammendrag
Forfattere
Espen Govasmark Brit SalbuSammendrag
Det er ikke registrert sammendrag