| 1. |
- Lundberg, Joacim, 1991-, et al.
(författare)
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Wet Dust Sampler : a Sampling Method for Road Dust Quantification and Analyses
- 2019
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Ingår i: Water, Air and Soil Pollution. - : Springer. - 0049-6979 .- 1573-2932. ; 230:8
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Tidskriftsartikel (refereegranskat)abstract
- In northern countries, the climate, and consequently the use of studded tyres and winter traction sanding, causes accumulation of road dust over winter and spring, resulting in high PM10 concentrations during springtime dusting events. To quantify the dust at the road surface, a method—the wet dust sampler (WDS)—was developed allowing repeatable sampling also under wet and snowy conditions. The principle of operation is flushing high-pressurised water over a defined surface area and transferring the dust laden water into a container for further analyses.In this paper, the latest version of the WSD is presented together with an evaluation of its performance. To evaluate the WDS, the ejected water amount was measured, as well as water losses in different parts of the sampling system, together with indicative dust measurement using turbidity as a proxy for dust concentration. The results show that the WDS, when accounting for all losses, have a predictable and repeatable water performance, with no impact on performance based on the variety of asphalt surface types included in this study, given undamaged surfaces. The largest loss was found to be water retained on the surface, and the dust measurements imply that this might not have as large impact on the sampled dust as could be expected. A theoretical particle mass balance shows small particle losses, while field measurements show higher losses. Several tests are suggested to validate and improve on the mass balances. Finally, the WDS is found to perform well and is able to contribute to further knowledge regarding road dust implications for air pollution.
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| 2. |
- Campeau, Audrey, et al.
(författare)
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Current forest carbon fixation fuels stream CO 2 emissions
- 2019
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Ingår i: Nature Communications. - : Nature Publishing Group. - 2041-1723. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Stream CO 2 emissions contribute significantly to atmospheric climate forcing. While there are strong indications that groundwater inputs sustain these emissions, the specific biogeochemical pathways and timescales involved in this lateral CO 2 export are still obscure. Here, via an extensive radiocarbon ( 14 C) characterisation of CO 2 and DOC in stream water and its groundwater sources in an old-growth boreal forest, we demonstrate that the 14 C-CO 2 is consistently in tune with the current atmospheric 14 C-CO 2 level and shows little association with the 14 C-DOC in the same waters. Our findings thus indicate that stream CO 2 emissions act as a shortcut that returns CO 2 recently fixed by the forest vegetation to the atmosphere. Our results expose a positive feedback mechanism within the C budget of forested catchments, where stream CO 2 emissions will be highly sensitive to changes in forest C allocation patterns associated with climate and land-use changes. © 2019, The Author(s).
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| 3. |
- Lagerström, Maria, 1986, et al.
(författare)
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In situ release rates of Cu and Zn from commercial antifouling paints at different salinities
- 2018
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Ingår i: Marine Pollution Bulletin. - : Elsevier BV. - 0025-326X .- 1879-3363. ; 127, s. 289-296
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Tidskriftsartikel (refereegranskat)abstract
- Antifouling paints are environmentally risk assessed based on their biocidal release rates to the water phase. In situ release rates of copper (Cu) and zinc (Zn) were derived for five commercial paints in two recreational marinas with different salinities (5 and 14 PSU) using an X-Ray Fluorescence spectrometer (XRF). Salinity was found to significantly affect the Cu release, with twice the amount of Cu released at the higher salinity, while its influence on the Zn release was paint-specific. Site-specific release rates for water bodies with salinity gradients, e.g. the Baltic Sea, are therefore necessary for more realistic risk assessments of antifouling paints. Furthermore, the in situ release rates were up to 8 times higher than those generated using standardized laboratory or calculation methods. The environmental risk assessment repeated with the field release rates concludes that it is questionable whether the studied products should be allowed on the Swedish market.
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| 4. |
- Amvrosiadi, Nino, et al.
(författare)
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Water storage dynamics in a till hillslope : the foundation for modeling flows and turnover times
- 2017
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Ingår i: Hydrological Processes. - : John Wiley and Sons Ltd. - 0885-6087 .- 1099-1085. ; 31:1, s. 4-14
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Tidskriftsartikel (refereegranskat)abstract
- Studies on hydrology, biogeochemistry, or mineral weathering often rely on assumptions about flow paths, water storage dynamics, and transit times. Testing these assumptions requires detailed hydrometric data that are usually unavailable at the catchment scale. Hillslope studies provide an alternative for obtaining a better understanding, but even on such well-defined and delimited scales, it is rare to have a comprehensive set of hydrometric observations from the water divide down to the stream that can constrain efforts to quantify water storage, movement, and turnover time. Here, we quantified water storage with daily resolution in a hillslope during the course of almost an entire year using hydrological measurements at the study site and an extended version of the vertical equilibrium model. We used an exponential function to simulate the relationship between hillslope discharge and water table; this was used to derive transmissivity profiles along the hillslope and map mean pore water velocities in the saturated zone. Based on the transmissivity profiles, the soil layer transmitting 99% of lateral flow to the stream had a depth that ranged from 8.9 m at the water divide to under 1 m closer to the stream. During the study period, the total storage of this layer varied from 1189 to 1485 mm, resulting in a turnover time of 2172 days. From the pore water velocities, we mapped the time it would take a water particle situated at any point of the saturated zone anywhere along the hillslope to exit as runoff. Our calculations point to the strengths as well as limitations of simple hydrometric data for inferring hydrological properties and water travel times in the subsurface.
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| 5. |
- Longo, Catherine S., et al.
(författare)
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Role of trophic models and indicators in current marine fisheries management
- 2015
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Ingår i: Marine Ecology Progress Series. - : Inter-Research Science Center. - 0171-8630 .- 1616-1599. ; 538, s. 257-272
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Tidskriftsartikel (refereegranskat)abstract
- The previous decade has witnessed a flourishing of studies on how fisheries and marine food webs interact, and how trophicmodels and indicators can be used for assessment and management purposes. Acknowledging the importance of complex interactions among species, fishermen and the environment has led to a shift from single species to an ecosystem-wide approach in the science supporting fisheries management (e.g. Johannesburg Declaration, Magnuson-Stevens Act). Moreover, fisheries managers today acknowledge that fishing activities are linked to a range of societal benefits and services, and their work is necessarily amulti-objective practice (i.e. ecosystem-based management). We argue that the knowledge accumulated thus far points to tropho-dynamic models and indicators as key tools for such multi-dimensional assessments. Nevertheless, trophodynamic approaches are still underutilised in fisheriesmanagement. More specifically,most management decisions continue to rely on single species and sector-specific models. Here we review examples of applications of trophodynamic indicators within fisheries assessments in wellstudied ecosystems, and discuss progressmade (as well as lack thereof) towards increased integration of these metrics into marine resource management. Having clarified how trophic indicators fit within current policy and management contexts, we propose ways forward to increase their use in view of futuremanagement challenges.
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| 6. |
- Pansch, Christian, et al.
(författare)
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A new flow-through bioassay for testing low-emission antifouling coatings
- 2017
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Ingår i: Biofouling. - : Informa UK Limited. - 0892-7014 .- 1029-2454. ; 33:8, s. 613-623
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Tidskriftsartikel (refereegranskat)abstract
- Current antifouling (AF) technologies are based on the continuous release of biocides into the water, and consequently discharge into the environment. Major efforts to develop more environmentally friendly coatings require efficient testing in laboratory assays, followed by field studies. Barnacles are important fouling organisms worldwide, increasing hydrodynamic drag on ships and damaging coatings on underwater surfaces, and thus are extensively used as models in AF research, mostly in static, laboratory-based systems. Reliable flow-through test assays for the screening of biocidecontaining AF paints, however, are rare. Herein, a flow-through bioassay was developed to screen for diverse low-release biocide paints, and to evaluate their effects on pre- andpost-settlement traits in barnacles. The assay distinguishes between the effects from direct surface contact and bulk-water effects, which are crucial when developing low-emission AF coatings. This flow-through bioassay adds a new tool for rapid laboratory-based first-stage screening of candidate compounds and novel AF formulations.
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| 7. |
- Scaini, Anna, et al.
(författare)
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Following tracer through the unsaturated zone using a multiple interacting pathways model : Implications from laboratory experiments
- 2019
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Ingår i: Hydrological Processes. - : John Wiley and Sons Ltd. - 0885-6087 .- 1099-1085. ; 33:17, s. 2300-2313
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Tidskriftsartikel (refereegranskat)abstract
- Models must effectively represent velocities and celerities if they are to address the old water paradox. Celerity information is recorded indirectly in hydrograph observations, whereas velocity information is more difficult to measure and simulate effectively, requiring additional assumptions and parameters. Velocity information can be obtained from tracer experiments, but we often lack information on the influence of soil properties on tracer mobility. This study features a combined experimental and modelling approach geared towards the evaluation of different structures in the multiple interacting pathways (MIPs) model and validates the representation of velocities with laboratory tracer experiments using an undisturbed soil column. Results indicate that the soil microstructure was modified during the experiment. Soil water velocities were represented using MIPs, testing how the (a) shape of the velocity distribution, (b) transition probability matrices (TPMs), (c) presence of immobile storage, and (d) nonstationary field capacity influence the model's performance. In MIPs, the TPM controls exhanges of water between pathways. In our experiment, MIPs were able to provide a good representation of the pattern of outflow. The results show that the connectedness of the faster pathways is important for controlling the percolation of water and tracer through the soil. The best model performance was obtained with the inclusion of immobile storage, but simulations were poor under the assumption of stationary parameters. The entire experiment was adequately simulated once a time-variable field capacity parameter was introduced, supporting the need for including the effects of soil microstructure changes observed during the experiment. © 2019 The Authors
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| 8. |
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| 9. |
- Nielsen, Maria, et al.
(författare)
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Nanomaterials in the European chemicals legislation-methodological challenges for registration and environmental safety assessment
- 2021
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Ingår i: Environmental Science: Nano. - : Royal Society of Chemistry. - 2051-8153 .- 2051-8161. ; 8:3, s. 731-747
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Tidskriftsartikel (refereegranskat)abstract
- In the European Union the Annexes of its chemical legislation (REACH) were revised and now clarify the technical data requirements for nanomaterials (NMs). These new provisions, effective from January 1, 2020, introduce requirements for manufacturers, importers and downstream users regarding registration and safety assessment of NMs. This study aims to assess the availability and suitability of methods needed to comply with the new regulatory provisions on NMs for physico-chemical characterisation and environmental fate and effects. The scientific literature and relevant test guideline frameworks were reviewed to identify applicable methods. These were subsequently evaluated and categorised as either: 'internationally accepted test guideline or standard (TGS)', 'internationally accepted test guideline or standard under development (TGSUD)', 'established as standard methods in scientific literature (SCI)', 'other methods and/or more research needed (O)' or 'no method (N)'. We find that 80% of the information requirements and a bit more than 40% of the waiving criteria in the new REACH Annexes are supported by methods that are available as TGS, TGSUD or SCI. Most of the relevant methods in the scientific literature are included in recent OECD guidance documents or ECHA guidance. We recommend that a targeted effort is made to develop protocols and guidelines for methods to determine NM adsorption/desorption, degradation, exposure scenarios and ability to cross biological membranes. Here methods to fulfil the information requirements and waiving criteria are currently lacking. Furthermore, we recommend that increasing attention is directed towards regulatory reliability and relevance of the information that is submitted by the registrants.
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| 10. |
- Yang, Shun-Han, 1987, et al.
(författare)
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Wave energy converters in array configurations—Influence of interaction effects on the power performance and fatigue of mooring lines
- 2020
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Ingår i: Ocean Engineering. - : Elsevier BV. - 0029-8018 .- 1873-5258. ; 211:1
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Tidskriftsartikel (refereegranskat)abstract
- In an array system of wave energy converters (WECs), hydrodynamic interactions between the WECs occur through the absorption, radiation, and diffraction of waves. The main objective of this study was to analyse hydrodynamic interactions between floating point-absorbing WECs and the influence of this interaction on the power performance and fatigue life of the WECs’ mooring lines. The hydrodynamic and structural response of the WEC systems were analysed using primarily potential flow theory, Morison equation, and continuum mechanics theory. Four 2-WEC models and two 10-WEC models were studied, among which different separating distances and mooring configurations were considered. The models were simulated for various environmental loading conditions. The results from each simulation were evaluated in terms of the power performance of each WEC, accumulated fatigue damage in each mooring line, and the levelised cost of energy (LCoE). The hydrodynamic interactions show a larger impact on the ten-WEC simulation models. In the simulations using the ten-WEC models accounting for hydrodynamic interactions, the fatigue damage in the mooring lines is varied at an average of 15% and up to an order of magnitude difference. A similar comparison for power performance showed an approximate 10% difference in the results. The LCoE calculation of the 10-WEC array system showed LCoE values ranging from -40% to +200% relative to the simulations that did not consider hydrodynamic interaction effects. Comparatively, the LCoE calculation of the 2-WEC model was either reduced by 17% or increased by 23% when the hydrodynamic interaction was included in the simulation model.
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