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.
2006
Forfattere
Roshan M. Bajracharya Subodh Sharma Bed Mani Dahal Bishal K. Sitaula Alhaji JengSammendrag
No abstract has been registered
Forfattere
Aldo Marchetto Rosario Mosello Gabriele A. Tartari John Derome Kirsti Derome Pia Sorsa Nils König Nicholas Clarke Erwin Ulrich Anna KowalskaSammendrag
Working Ring Test (WRT) was organised in the framework of the EU Regulation (EC) No 2152/2003 (`Forest Focus`) and of the UN/ECE Program `ICP Forests` in order to evaluate the overall performance of the laboratories monitoring atmospheric deposition and soil solution in European Forests, and to verify the improvement in the analytical quality as the results of the QA/QC work carried out in the laboratories which participated to a previous WRT. Seven natural samples of atmospheric deposition and soil solutions and 5 synthetic solutions were distributed to 52 laboratories, which analysed them using their routine method for the following variables: pH, conductivity, calcium, magnesium, sodium, potassium, ammonium, sulphate, nitrate, chloride, total alkalinity, phosphate, total dissolved nitrogen, dissolved organic carbon, aluminium, copper, iron, manganese, zinc, total phosphorus, total sulphur and silica. For each variable, a Data Quality Objective was defined, based on the results of the previous WRT, the comparison with the DQOs of other international networks, and the importance of the variable in deposition and soil solution monitoring. It resulted that 38% of the results do not meet the DQO, showing for which variables and in which laboratories improvement in analytical performance is needed. The results of the exercise clearly show that the use of data check procedures, as those described in the ICP Forests manual for sampling and analysis of atmospheric deposition, would make it possible to detect the presence of outliers or results not accurate, and would greatly improve the overall performance of the laboratories. Some analytical methods were found not suitable to the samples used in this WRT, nor to atmospheric deposition samples in European forests, and they include outdated methods, such as turbidimetry or nephelometry for the determination of sulphate, silver nitrate titration and ion selective electrode for chloride, Kjeldahl digestion for the determination of ammonium and organic nitrogen, and colorimetric titrations for alkalinity. A detailed discussion of the analyses of total dissolved nitrogen, dissolved organic carbon and total alkalinity is also provided, as they were the variables for which more analytical difficulty arose. Finally, a comparison between the results of this WRT and those of the previous exercise showed that the analytical performance of the laboratories participating in both WRTs improved as a consequence of the adoption of QA/QC procedures.
Forfattere
Harald Bratli Erik Framstad Jogeir N. Stokland Odd Egil StabbetorpSammendrag
No abstract has been registered
Sammendrag
No abstract has been registered
Forfattere
Tor J. JohansenSammendrag
No abstract has been registered
Sammendrag
No abstract has been registered
Sammendrag
No abstract has been registered
Forfattere
Fadi Suliman Helen French Lars Egil Haugen Anne Kristine SøvikSammendrag
In order to investigate the influence of biological growth on flow and transport patterns in horizontal subsurface flow constructed wetlands, bromide tracer experiments were conducted in two 3 In long tanks. The tanks were filled with light weight aggregates and shell sand, respectively. The hydraulic conductivity, drainable porosity and dispersivity of the two filter media were determined before and after biological growth. The obtained breakthrough curves of bromide tracer showed that biological growth caused a pronounced reduction in drainable porosity; mainly for shell sand whereas its effect on saturated hydraulic conductivity was negligible. The spatial distribution of the bromide after biological growth in the two filter media showed that the flow occurred preferentially along certain paths. However, in the light-weight aggregates filter medium, biological growth with possible clogging effects seems to reduce the efficiency of some preferential flow paths, increase the retention time, and hence, improves the system treatment efficiency This study showed that selecting a filter medium including coarse fractions to some extent can mitigate the potential negative effects of bioclogging. (c) 2006 Elsevier B.V. All rights reserved.
Sammendrag
No abstract has been registered
Forfattere
T. Salo B Stenberg C. Lundström L.S. Jensen S. Bruun A. Pedersen T.A Breland T. Henriksen Audun Korsæth H. Palmason J. GudmundssonSammendrag
No abstract has been registered