| 1. |
- Uddh Söderberg, Terese, 1976-, et al.
(författare)
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Challenges in geochemical modelling of metal(loid) solubility and binding mechanisms along a soil profile at a multi-contaminated site
- 2024
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Ingår i: Applied Geochemistry. - : Elsevier. - 0883-2927 .- 1872-9134. ; 170
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Tidskriftsartikel (refereegranskat)abstract
- Recognising the need for robust models in predicting groundwater contamination risks from metal(loid)s in contaminated topsoil, this study focuses on the geochemical behaviour of As, Cd, Cu, Pb, Sb and Zn in one of Sweden’s most heavily contaminated areas. Samples were collected from the waste zone and underlying subsoil down to 5 meters and batch experiments were carried out to assess pH-dependent solubility. The results indicate that Cd, Cu, Pb and Zn are efficiently immobilized in the waste zone, while As(V) and Sb(V) are more easily leached. With the exception of Pb and Cu at high pH, the mobilized metals appear to be predominantly in a truly dissolved state, as confirmed by ultrafiltration at 10 kDa.Speciation modelling using Visual MINTEQ did not suggest a significant role of precipitates such as Zn or Pb arsenates and phosphates, although their involvement could not be ruled out. To better understand sorption/desorption patterns, a multi-surface geochemical model was established, drawing on the Stockholm Humic and CD-MUSIC models for organic matter and Fe/Al (hydr)oxide sorption. However, when default parameters were used, the model consistently overestimated the solubility of Cd, Cu, Pb and Zn in both the waste zone and the uncontaminated subsoil. In contrast, As(V) solubility was generally underestimated, also when the reactive surface area of the Fe- and Al (hydr)oxides was decreased in the model. The model's performance was better for Sb(V), though not without imperfections. When the parameters for organic matter were adjusted such that 100% of the solid-phase organic matter was active with respect to ion binding, but only 25% of the dissolved organic matter, the model description improved considerably for Pb and Cu in the upper soil layers. The model revealed distinct differences in the adsorption behaviour of the metal cations, with Pb being sorbed mostly to Fe/Al (hydroxides), whereas a considerable part of Cu was sorbed to organic matter, particularly in the waste zone.Possibly, the dissolution of easily weatherable metal-containing mineral phases may have contributed to the poor model performance for Cd, Zn and for Cu in the deeper soil layers, although other factors, such as a contribution of hydrous SiO2 or Mn oxides to metal binding, could not be ruled out. Metal sorption to carbonate phases may also have been a contributing factor in the waste zone. Lastly, the reactivity of Fe- and Al (hydr)oxides may have been overestimated by oxalate extraction when default parameters for high-surface-area ferrihydrite were applied. These findings provide valuable insights for environmental management and underscore the need for a more detailed characterization of metal(loid) sorption in contaminated soils, as well as the development of improved modelling strategies to enhance solubility predictions.
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| 2. |
- Giechaskiel, Barouch, et al.
(författare)
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Contribution of Road Vehicle Tyre Wear to Microplastics and Ambient Air Pollution
- 2024
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Ingår i: Sustainability. - : MDPI. - 2071-1050. ; 16:2
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Tidskriftsartikel (refereegranskat)abstract
- Tyre particles are generated by shear forces between the tread and the road or by volatilisation. Tyre abrasion (wear) contributes from one-third to half of microplastics unintentionally released into the environment. The major part ends up in the soil, a considerable amount is released into the aquatic environment, and a small percentage becomes airborne. Nevertheless, tyre abrasion contributes to 5–30% of road transport particulate matter (PM) emissions. This corresponds to approximately 5% of total ambient PM emissions. The particle mass size distribution peak at around 20 to 100 μm, with a second peak in the 2–10 μm range. A nucleation mode has been reported in some studies. The absolute abrasion levels depend on the tyre, vehicle, and road characteristics, but also on environmental conditions and driving style. Most tyre particle emission factors in the literature are based on data prior to the year 2000.
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| 3. |
- Gustafsson, Marcus, 1987-, et al.
(författare)
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Climate performance of liquefied biomethane with carbon dioxide utilization or storage
- 2024
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Ingår i: Renewable and sustainable energy reviews. - : Elsevier. - 1364-0321 .- 1879-0690. ; 192
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Tidskriftsartikel (refereegranskat)abstract
- In the process of upgrading biogas to biomethane for gas grid injection or use as a vehicle fuel, biogenic carbon dioxide (CO₂) is separated and normally emitted to the atmosphere. Meanwhile, there are a number of ways of utilizing CO₂ to reduce the dependency on fossil carbon sources. This article assesses the climate performance of liquefied biomethane for road transport with different options for utilization or storage of CO₂. The analysis is done from a life cycle perspective, covering the required and avoided processes from biogas production to the end use of biomethane and CO₂. The results show that all of the studied options for CO₂ utilization can improve the climate performance of biomethane, in some cases contributing to negative CO₂ emissions. One of the best options, from a climate impact perspective, is to use the CO₂ internally to produce more methane, although continuous supply of hydrogen from renewable sources can be a challenge. Another option that stands out is concrete curing, where CO₂ can both replace conventional steam curing and be stored for a long time in mineral form. Storing CO₂ in geological formations can also lead to negative CO₂ emissions. However, with such long-term storage solutions, opportunities to recycle biogenic CO₂ are lost, together with the possibility of de-fossilizing processes that require carbon, such as chemical production and horticulture.
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| 4. |
- Järlskog, Ida, 1991-, et al.
(författare)
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Microplastic emissions from wear of road markings : overview and assessment for Swedish conditions
- 2024
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Traffic-derived microplastics, i.e., tyre wear particles, wear from polymer-modified bitumen, and road marking wear are assumed to be one of the largest sources of microplastic contamination. Road markings as a source of microplastic emissions are still a rather unexplored research area, and there arestill large knowledge gaps regarding annual wear, concentrations in different environments, and eventual risks for flora and fauna. This report has aimed to estimate the annual wear of road markings in Sweden and to investigate the knowledge on a municipal level related to road markings and wear. In addition, road markings from different traffic environments have been documented throughout the project, and the wear on these has been investigated. The project has also aimed to clarify which processes that contribute to the wear of road markings, as well as to map out which types of road markings that are subjected to specific types of wear. A survey was sent out to all municipalities in Sweden with questions about the type of road marking material, annual purchases, budget, wear rate, wear-prone traffic environments, and main causes of wear on road markings. In total, we received answers from 223 out of 290 municipalities. The result from the survey indicates that transverse road markings (e.g., yield lines, and pedestrian crossings), driving lines, and lines within roundabouts wear fast and that winter maintenance, use of studded tyres, and traffic loads are the main causes to wear. In general, the knowledge was low regarding annual purchases/applied amounts and many of the municipals mentioned that they do not have the budget to maintain road markings to a desirable extent. For upcoming procurements, we recommend the municipalities to make higher demands on the quality of the material, as well as adhesion and maintenance which might result in lower costs, a need for less material, and thereby also a reduced wear.
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| 5. |
- Järlskog, Ida, 1991-, et al.
(författare)
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Reply to road markings and microplastics - a critical literature review
- 2024
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Ingår i: Transportation Research Part D. - : Elsevier. - 1361-9209 .- 1879-2340. ; 132
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Tidskriftsartikel (refereegranskat)abstract
- This is a reply to the recently published paper Road markings and microplastics - A critical literature review. In our opinion, that paper presented a deceptive picture, of why we found it necessary to write a short reply where we comment on two major flaws: the stated lack of road markings in environmental samples, and the definition of microplastics. We discuss possible reasons for the absence of positive findings in environmental samples and relate that to two of the major issues within the research area of microplastics- the complexity of environmental samples and the analytical difficulties. We also argue that it can be relevant for upcoming studies to report both total microplastic concentration and polymer content to facilitate the comparison between studies since the definition of microplastics might change over time.
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| 6. |
- Järlskog, Ida, 1991-, et al.
(författare)
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Trafikrelaterade mikroplaster i luftburna partiklar : Sammanställning av källfördelning i prover från Hornsgatan och Sveavägen 2020–2021
- 2024
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I denna rapport har partikelinnehållet i luftprover insamlade med passiva Sigma-II mätare i anslutning till befintliga mätstationer på Hornsgatan och Sveavägen analyserats och sammanställts. Prover samlades in under tre perioder mellan oktober och december 2020 samt under fyra perioder mellan mars och april 2021. Syftet har varit att kvantifiera andelen trafikrelaterad mikroplast i proverna, det vill säga däckpartiklar och vägmarkeringspartiklar. Alla prover har analyserats med en automatiserad SEM/EDX-metod i storleksfraktionen 1‒80 μm och partiklarna har kategoriserats in i följande partikelklasser: mineralpartiklar, metallpartiklar, organiska partiklar (t.ex. växtdelar och pollen), däckpartiklar större än 5 μm, bitumenpartiklar större än 5 μm, däck- och bitumenpartiklar mindre än 5 μm (TBiWP <5 μm), vägmarkeringspartiklar samt glaspärlor. Resultaten presenteras både som relativ sammansättning, det vill säga antal partiklar/partikelklass (%), masskoncentration i μg/m3, och som massprocent (%). Resultaten redovisar både hela den provtagna fraktionen, 1‒80 μm, och uppdelat i storleksfraktionen 2.5‒10 μm, där den sistnämnda är tänkt att kunna jämföras med befintliga luftmätningar.
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| 7. |
- Nel, Ben, et al.
(författare)
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Stored Energies and Q-factor expressed in Material derivatives
- 2024
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Ingår i: IEEE Antennas and Wireless Propagation Letters. - 1548-5757. ; 23:1, s. 19-23
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Tidskriftsartikel (refereegranskat)abstract
- Stored energies of radiating systems have generated research interest for several decades due to their relationship with Q-factor and fractional bandwidth. In this paper material derivatives are used to provide a new interpretation of widely used stored energy expressions. This provides a fundamental relationship between stored energies of radiating systems and their electromagnetic material properties. It is shown that electric stored energy is related to the electric material parameter (permittivity) derivative. Similarly, magnetic stored energy is linked to the derivative of the permeability. Further, as an extension Cauchy-Riemann equations are used to relate stored energy to dissipation.
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| 8. |
- Polukarova, Maria, 1992-, et al.
(författare)
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Comprehensive approach to national tire wear emissions : Challenges and implications
- 2024
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 924
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Tidskriftsartikel (refereegranskat)abstract
- The use of vehicle tires has been identified as a major source of microplastics in the environment and an increasing source of urban particulate air pollution. In light of increasing traffic volumes, increasingly heavier and more powerful vehicles due to trends and electrification, and the lack of tire wear regulation, methods to estimate and monitor changes in national emissions are needed as input for environmental impact assessments. Emission estimations of tire wear are made either based on the mileage approach or the sales approach. This study aims to investigate if and how the mileage approach can be improved by using emission factors for passenger cars and LDVs based on our own measurements and emission factors from the literature for HDVs and buses. An approach with emission factor adjustments based on weight and number of tires in combination with highly detailed mileage data has been evaluated. Sales approach calculations have been used to validate the method. A secondary aim was to use the new mileage approach framework to calculate the national tire wear emissions for Sweden. These calculations resulted in slightly lower total emissions than previous estimations provide, but with higher emissions for passenger cars and light-duty vehicles, and lower emissions for heavy-duty vehicles and motorcycles. Passenger cars constitute more than half of the total emissions. It is concluded that even though the framework offers greater detail, thus increasing the possibilities to adjust for changes in emission factors and mileages in specific vehicle categories, the challenges posed by such factors as the lack of measured emission factors for heavy-duty vehicles and uncertainties regarding the quality of mileage statistics makes the estimations uncertain.
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| 9. |
- Santoro, V., et al.
(författare)
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HighNESS conceptual design report: Volume I
- 2024
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Ingår i: Journal of Neutron Research. - 1023-8166 .- 1477-2655. ; 25:3-4, s. 85-314
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Tidskriftsartikel (refereegranskat)abstract
- The European Spallation Source, currently under construction in Lund, Sweden, is a multidisciplinary international laboratory. Once completed to full specifications, it will operate the world’s most powerful pulsed neutron source. Supported by a 3 million Euro Research and Innovation Action within the EU Horizon 2020 program, a design study (HighNESS) has been completed to develop a second neutron source located below the spallation target. Compared to the first source, designed for high cold and thermal brightness, the new source has been optimized to deliver higher intensity, and a shift to longer wavelengths in the spectral regions of cold (CN, 2–20 Å), very cold (VCN, 10–120 Å), and ultracold (UCN, >500 Å) neutrons. The second source comprises a large liquid deuterium moderator designed to produce CN and support secondary VCN and UCN sources. Various options have been explored in the proposed designs, aiming for world-leading performance in neutronics. These designs will enable the development of several new instrument concepts and facilitate the implementation of a high-sensitivity neutron-antineutron oscillation experiment (NNBAR). This document serves as the Conceptual Design Report for the HighNESS project, representing its final deliverable.
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| 10. |
- Santoro, V., et al.
(författare)
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HighNESS conceptual design report: Volume II. the NNBAR experiment.
- 2024
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Ingår i: Journal of Neutron Research. - 1023-8166 .- 1477-2655. ; 25:3-4, s. 315-406
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Tidskriftsartikel (refereegranskat)abstract
- A key aim of the HighNESS project for the European Spallation Source is to enable cutting-edge particle physics experiments. This volume presents a conceptual design report for the NNBAR experiment. NNBAR would exploit a new cold lower moderator to make the first search in over thirty years for free neutrons converting to anti-neutrons. The observation of such a baryon-number-violating signature would be of fundamental significance and tackle open questions in modern physics, including the origin of the matter-antimatter asymmetry. This report shows the design of the beamline, supermirror focusing system, magnetic and radiation shielding, and anti-neutron detector necessary for the experiment. A range of simulation programs are employed to quantify the performance of the experiment and show how background can be suppressed. For a search with full background suppression, a sensitivity improvement of three orders of magnitude is expected, as compared with the previous search. Civil engineering studies for the NNBAR beamline are also shown, as is a costing model for the experiment.
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