Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2011
Abstract
Due to sewage sludge application on soils, terrestrial ecosystems are very likely to be exposed to silver nanoparticles (AgNPs) and it is thus important to understand the behavior of Ag NPs once in contact with soil components. The aim of this work was to compare the behavior of silver under three forms, silver nitrate, citrate stabilized AgNPs (C-ANPs) and uncoated AgNPs (P-AgNPs), in two soils with contrasting organic matter content, and over time. The physical and chemical properties of the studied soils as well as the nanoparticles size, shape, crystallographic structure and specific surface area were characterized. Soil samples were spiked with silver nitrate, C-AgNPs or P-AgNPs, and let for ageing 2 hours, 2 days, 5 weeks or 10 weeks before they were submitted to sequential extraction. The ionic silver solution and the two AgNPs types were radiolabeled so that we could detect and quantify silver by gamma spectrometry by measuring the 110mAg tracer in the different sequential extraction fractions. We thereby obtained for each silver form, soil type and time point a distribution of silver in the different fractions. Silver was generally more mobile in the mineral soil, although the fractionation patterns were very different for the three silver types in both cases. Over 20% of the total C-AgNPs concentration were water soluble in both soils (<5% for AgNO3 and P-AgNPs) the first two days after spiking, but the fraction decreased to trace levels thereafter. This was compensated by an increase in the reducible fraction. Regarding P-AgNPs, 80% were not extractable at all, but contrary to AgNO3 and C-AgNPs, the water soluble and ion exchangeable fractions did not decrease over time in the mineral soil, and even increased in the organic soil.
Abstract
No abstract has been registered
Authors
Adam Paruch Trond Mæhlum Hanna Obarska-Pempkowiak Magdalena Gajewska Ewa Wojciechowska Arkadiusz OstojskiAbstract
This article describes Norwegian and Polish experiences concerning domestic wastewater treatment obtained during nearly 20 years of operation for constructed wetland (CW) systems in rural areas and scattered settlements. The Norwegian CW systems revealed a high performance with respect to the removal of organic matter, biogenic elements and faecal indicator bacteria. The performance of the Polish CW systems was unstable, and varied between unsatisfied and satisfied treatment efficiency provided by horizontal and vertical flow CWs, respectively. Therefore, three different concepts related to the improvement of CW technology have been developed and implemented in Poland. These concepts combined some innovative solutions originally designed in Norway (e.g. an additional treatment step in biofilters) with Polish inspiration for new CWs treating rural domestic wastewater. The implementation of full-scale systems will be evaluated with regard to treatment efficiency and innovative technology; based on this, a further selection of the most favourable CW for rural areas and scattered settlements will be performed.
Authors
Frank MillerAbstract
No abstract has been registered
Authors
Per Stålnacke Geoffrey Gooch Sekhar Udaya Nagothu Ingrid Nesheim Line Johanne Barkved Bruna Grizzetti Johannes Deelstra Håkon Thaulow Dag BergeAbstract
No abstract has been registered
Authors
Amy M P Oen Barbara Beckingham Upal Gosh Marie Elmquist Kruså RG Luthy Thomas Hartnik Thomas Henriksen Gerard CornelissenAbstract
No abstract has been registered
Authors
Tatsiana Espevig Michelle DaCosta Lindsey Hoffman Trygve S. Aamlid Anne Marte Tronsmo Bruce B. Clarke Bingru R. HuangAbstract
Field trials at two locations in Norway previously demonstrated differences in winter survival between two Agrostis species used for turf, velvet bentgrass (VB; A. canina L.) and creeping bentgrass (CB; A. stolonifera L.). The objectives of this study were to compare freezing tolerance and crowncarbohydrate composition of VB and CB. We also compared a direct and two indirect methods of measurements of freezing tolerance. Treatments consisted of: (i) nonacclimated (NA); (ii) acclimation at 2°C for 2 wk (A2); (iii) acclimation at 2°C for 4 wk (A4); and (iv) acclimation at 2°C for 4 wk plussubzero acclimation at –2°C for 2 wk (A4+SZA2). Crowns were harvested for determination of carbohydrates and freezing tolerance. Freezing tolerance (lethal temperature for 50% of the test population [LT50]) was based on whole plant survival (WPS), 2,3,5-triphenyltetrazolium chloride (TTC)reduction, and electrolyte leakage (EL). There were no significant difference in freezing tolerance between VB and CB. The LT50 based on WPS was significantly lower for plants exposed to A2 (–12.7°C), A4 (–14.5°C), and A4+SZA2 (–14.6°C) compared to the NA control treatment (–8.4°C). The concentrations of fructans and sucrose were significantly higher in A2 compared to NA plants of both species, but only fructans continued to increase at A4. The LT50 based on TTC reduction showed better correlation with LT50 based on WPS compared to LT50 values based on EL.
Abstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
No abstract has been registered