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A review of PFAS fingerprints in fish from Norwegian freshwater bodies subject to different source inputs
No full textThe extensive use of per- and polyfluorinated alkyl substances (PFAS) has resulted in many environmental point and diffuse sources. Identifying the source responsible for a pollution hot spot is vital for assessing remediation measures, however, as there are many possible sources of environmental PFAS pollution, this can be challenging. Chemical fingerprinting has been proposed as an approach to identify contamination sources. Here, concentrations and profiles (relative distribution profiles) of routinely targeted PFAS in freshwater fish from eight sites in Norway, representing three different sources: (1) production of paper products, (2) the use of aqueous film forming foams (AFFF), and (3) long-range atmospheric transport, were investigated. The data were retrieved from published studies. Results showed that fingerprinting of PFAS in fish can be used to identify the dominant exposure source(s), and the profiles associated with the different sources were described in detail. Based on the results, the liver was concluded to be better suited for source tracking compared to muscle. PFAS fingerprints originating from AFFF were dominated by perfluorooctanesulfonate (PFOS) and other perfluoroalkanesulfonic acids (PFSA). Fingerprints originating from both long-range atmospheric transport and production of paper products were associated with high percentages of long chained perfluoroalkyl carboxylic acids (PFCA). However, there were differences between the two latter sources with respect to the ∑PFAS concentrations and ratios of specific PFCA pairs (PFUnDA/PFDA and PFTrDA/PFDoDA). Low ∑PFAS concentrations were detected in fish exposed mainly to PFAS via long-range atmospheric transport. In contrast, ∑PFAS concentrations were high and high percentages of PFOS were detected in fish exposed to pollution from production of paper products. The source-specific fingerprints described here can be used for source tracking.A review of PFAS fingerprints in fish from Norwegian freshwater bodies subject to different source inputspublishedVersionpublishedVersio
Regolith and host rock influences on CO<inf>2</inf> leakage: Active source seismic profiling across the Little Grand Wash fault, Utah
No full textpublishedVersio
Hydrochemical and biotic control on iron incrustations in groundwater heat pump systems: Case study from a saline, anoxic aquifer in Melhus, Norway
Get PDFClogging by incrustations of nine groundwater heat pump (GWHP) systems in Melhus, Norway have been investigated by field and laboratory methods for water quality and incrustation composition. Iron oxides incrust systems extracting relatively shallow, low-saline groundwater, while iron sulfides are associated with deeper, more saline groundwater. Hydrochemical conditions in iron oxide clogged GWHP systems are favorable for the growth of iron-oxidizing bacteria. Also, sediment deposits clog the well systems. The variety of incrustation problems detected in Melhus emphasizes that clogging must be expected and dealt with, instead of solely attempted avoided through system design or re-location.Hydrochemical and biotic control on iron incrustations in groundwater heat pump systems: Case study from a saline, anoxic aquifer in Melhus, NorwaypublishedVersio
Formation and availability of methylmercury in mercury-contaminated sediment: effects of activated carbon and biochar amendments
Get PDFPurpose As the formation of toxic and bioaccumulative methylmercury (MeHg) in Hg-contaminated sediments is of great concern worldwide, suitable remediation options are needed. Activated carbon (AC) amendment is a contested alternative due to uncertainties surrounding sorption efficiency and its potential role in aiding MeHg formation. The purpose of this study was therefore to demonstrate AC performance under favourable conditions for Hg-methylation and to further understand the role AC plays in the methylation process. Materials and methods Mercury-contaminated sediment (57.1 mg kg−1) was sampled from the Gunneklev fjord, a site known as the most heavily contaminated fjord in Norway. In a laboratory experiment, lignite AC (A-AC, 5%) or activated biochar (A-BC, 5%) along with dried algae biomass, serving as an excess source of easily degradable organic matter (OM) and sulphate, were added to sediment samples that were kept anoxic and dark over a period of 12 months. Results and discussion The amount of MeHg in sediment and porewater of the amended samples were measured at 0, 1, 3, 6, and 12 months and compared to an unamended control. A net increase of MeHg in the sediment was observed in both control and amended samples, but contrary to expectations, sediment MeHg was 5 and 3 times higher in the A-AC and A-BC treatments, respectively, relative to the control after 12 months. As the stimulation of Hg-methylation could not be attributed to the sorbents supplying more available OM or sulphate for dissimilatory sulphate reduction, it is speculated that the sorbents rather aid this process through shuttling of electrons between the substrates involved. Meanwhile, the A-AC and A-BC amendments strongly reduced the available MeHg-concentration in porewater (by 87% for A-AC and by 93% for A-BC after 12 months), confirming that AC sorbents can be used to effectively limit the transport of MeHg from sediments. Conclusion When considering remediation of OM-rich Hg-contaminated sediments with AC, caution is thus warranted, as the overall effect of reducing MeHg-transport out of the sediment could partly be offset by an increased fraction of MeHg in the sediment. Thin-layer capping with AC might therefore be preferable to complete mixing of AC and sediment.publishedVersio
WP 2 – Full-scale experiments at Ryggfonn Ryggfonn avalanche observations 2020/2021
Get PDFNGI continues to operate the avalanche test site at Ryggfonn in Stryn municipality, Vestland county, western Norway (61.969°N, 7.275°E). In addition to the field work and data collection performed in the context of WP2 – Avalanche dynamics in AARN, necessary repairs and updating of the data acquisition system at the Ryggfonn avalanche test site were carried out under this task. Maintenance was carried out to ensure that the site was ready for the 2021/22 winter season.NVE (Norges vassdrags- og energidirektorat
Work Package 3 – Hydrogeological methods, drainage and grouting
Get PDFGround works such as deep excavations and foundation works performed in soft clay can cause damage to neighbouring buildings and structures. Drainage causes pore pressure lowering, followed by consolidation settlements. The costs related to settlement damage can be substantial and there is a considerable potential for reducing these costs.
The risk of settlement damage caused by drainage and pore pressure reduction can be reduced during the early design phase of a project by undertaking the correct type of investigations and understanding the hydrogeological conditions. Furthermore, one may select construction methods, which reduce risk of drainage. In case the selected construction solution yields an unacceptable risk for settlement damage to surrounding buildings and infrastructure, remedial measures may be designed to mitigate the effects, followed by implementation and monitoring during the construction phase.
This report provides State-of-the-Art related to hydrogeological investigation methods, hydrogeological modelling and numerous measures to mitigate the effects of drainage to excavations. In addition, governing Norwegian rules and regulations are discussed, as well as the causes of drainage to excavations in Norwegian ground conditions.Norges forskningsråd / The Research Council of Norwa
