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Little attention has been paid to tailings from skarn ore deposits and their environmental impact, even though they can contain elevated content of elements of potential concern. Historical skarn tailings from a former scheelite mine at Yxsjöberg, Sweden, containing e.g. Be, Bi, Cu, F, Sn, S, W, and Zn were geochemically characterized as a first step to evaluate the potential environmental impact and if re-mining of the tailings can be a remediation option. Beryllium, Bi, F, and W are considered as elements of potential concern, and are at the same time listed by the European Commission (2017) as critical raw materials. Scheelite is considered as a relatively stable mineral but most research has been focused on extraction processes. A few laboratory studies have shown weathering of scheelite by artificial groundwater, where the release of WO42-was hypothesized to be due to anion exchange by CO32-. Thus, the release of W from scheelite should be favorable in skarn tailings due to the presence of carbonates. The tailings at Yxsjöberg were deposited between 1897 and 1963 in the Smaltjärnen Repository without dams or a complete cover, and have been in contact with the atmosphere for more than 30 years. Four vertical cores (P2, P4, P5, and P7) throughout the tailings were taken and divided into 134 subsamples, and analyzed for their total chemical composition and paste pH. Selected samples from different depths were mineralogically characterized using optical microscopy, scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS), Raman vibrational spectroscopy, and X-ray diffraction (XRD). Minerals, hand-picked from drilled rock cores, were analyzed for the element content, and a modified Element to Mineral Conversion (EMC) in combination with a 7-step sequential extraction of the tailings was used to pinpoint the quantitative distribution of elements between the minerals in the tailings. Scheelite weathering and secondary sequestration of W was studied in detail in one representative core. The release of elements to groundwater in the tailings and downstream surface water was measured monthly during 2018 to especially examine the mobility of W. The average concentrations of Be, Bi, Cu, Sn, Zn, W, F and S in the tailings were 280, 490, 950, 560, 300, and 960 ppm, and 1.9 and 1.2 wt.%, respectively. The uppermost tailings have been exposed to the atmosphere for more 30 years, with intensive pyrrhotite oxidation and carbonate dissolution, resulting in low pH (<4) condition, release of elements, and subsequent formations of secondary minerals such as gypsum and hydrous ferric oxides (HFO). Two different deposition periods were identified in one vertical profile. The later period of deposition extended from the ground surface down to 3.5 m, and the older from 3.6 to 6 m. Both periods had unoxidized tailings in the bottom and oxidized sulfides, depletion of calcite and HFO formations upwards. Tungsten was primarily found in scheelite and the abundance was 0.1 wt.% in the tailings at Yxsjöberg. Accumulation peaks of W were found with depth in P2, P4 and P7. In the upper peak of P4, 30% of the total W was associated with secondary HFO. This indicates that weathering of scheelite and secondary capturing of W had occurred in the tailings. At present time, a peak of W in water soluble phases where coinciding with accumulated C in the solid phase at 2.5m depth. Carbonate ions were released when calcite was neutralizing the acid produced in the upper oxidized tailings and the released CO32-was transported downwards to conditions with pH >7. There, it mainly had precipitated as secondary calcite, but small parts are hypothesized to have exchanged WO42-on the surface of scheelite,releasing WO42-to the pore water. In the oxidized tailings of the older and deeper tailing,goethite was found as rims around scheelite grains. This is probably due to Fe ions attracted to the negative surface of scheelite. This is suggested to decrease further weathering of scheelite, and also to some extent decrease the release of WO42-to the groundwater from above lying layers through adsorption. The changes in geochemical conditions in the tailings have decreased the water quality in receiving waters of Smaltjärnens Repository with increased concentrations of Ca, F, Fe,Mn, and SO42-. pH was on average 6.3 in the groundwater in the tailings and 5.7 in the surface water 300 m downstream. EC was on average 2.6 mS/cm in the groundwater and 131 μS/cm in the surface water. Low concentrations of dissolved W was found in the groundwater (max: 20 μg/l) in the tailings and in the downstream surface water the W concentration (max: 0.2 μg/l) was 20 times larger than the reference sample. These results show that scheelite is releasing W to a limited degree to downstream waters and are therefore a potential resource to re-mine to support the supply of critical raw materials in the EU. Beryllium, F, and Zn were released to the downstream surface water from the Smaltjärnen Repository, and to a higher degree than W. The rare and easily-weathered mineral danalite (Fe4Be3(SiO4)3S) contained approximately 40% of the total Be and Zn concentrations in the tailings and is suggested to be the major source to the release of Be and Zn. Fluorine was mainly found in fluorite which showed signs of weathering in the acidic condition in the uppermost oxidized tailings, subsequent with decreased content in the tailings. The mobility of these elements will be further studied.

Stormwater management is necessary to avoid flooding and pollutants that can spread further with the water and damage the environment. The legislation that regulates the management of stormwater can be difficult and complicated to interpret. The purpose of this project was to investigate the strategies and decision materials that exist today regarding municipalities’ stormwater management. That was investigated to understand how the legislation works today, whose responsibility it is to manage stormwater and whether there are any specific emission requirements for pollutants.In order to analyse and evaluate how the management of stormwater works in Swedish municipalities, Gotland, Sundsvall and Gothenburg were selected to be investigated, according to size variation and geographical spread. The stormwater strategies of the three municipalities were examined and their possible choice of measures were compared and evaluated. A theoretical modelling was made to investigate how the choices of measures could have affected the spread of pollutants from a specific area with a specific recipient. The area that was examined was selected by the company and the modelling was made using the tools CAD and StormTac.When the investigation was conducted, it was found that it can be difficult to interpret the regulations that exist. The municipalities' stormwater strategies and their choice of measures to manage pollution discharges would differ between the municipalities. The modelling showed that all choices of pollutant reduction measures would reduce pollutants compared to a situation without any treatment at all. The results also showed that the percentage reduction in pollutants would differ with the different choice of measure. The municipalities' have different pollution requirements in different situations, which makes it difficult to interpret their strategy and choice of measures. Despite this, Gothenburg's choice of method seemed to give the best results in this case.In general, it is difficult to determine which municipality is considered to have the best stormwater strategy. More analysis and information about the area's conditions and the recipient's well-being needs to be taken into account in order to be able to make a decision. This project shows that clearer legislation regarding stormwater management should be introduced in order for all municipalities in Sweden to work towards the same goals and achieve equal results.

Under senare år har klimatförändringar blivit alltmer märkbara i och med ökade förekomster av naturolyckor. Bland annat har skogsbränder, översvämningar och torka ökat i frekvens och kommer att öka ännu mer i framtiden, vilket kommer att ha konsekvenser för samhället. Även i Sverige har effekterna av klimatförändringar märkts av, till exempel genom att omfattande skyfall har drabbat områden såsom Gävleborg, Hammarö och Hagfors. Skyfallen har lett till omfattande översvämningar och skador som har inneburit stora kostnader för samhället. Som en del av arbetet med att hantera effekterna av ett förändrat klimat jobbar kommuner och länsstyrelser med klimatanpassning, vilket bland annat innefattar att ha beredskap vid händelse av naturkatastrofer. Detta innefattar exempelvis att kartlägga effekter av skyfall genom att göra skyfallskarteringar. I Håbo kommun har man inkluderat klimatanpassning i flera av sina policys och har sedan en tid tillbaka arbetat med att utreda effekterna av skyfall i kommunen. Sedan 2023 finns en skyfallskartering över hela Uppsala län, som även inkluderar Håbo kommun. För att kunna planera förebyggande åtgärder vill nu kommunen kartlägga konsekvenserna av 100- och 500-årsregn för ett antal samhällsviktiga verksamheter inom centrala Bålsta samt utreda vilka kostnader kommunen kan ställas inför.  I studien undersöktes byggnader och transportleder som ansågs prioriterade av Håbo kommun. Dessa byggnader och transportleder benämns som av kommunen prioriterade verksamheter (KPV). Med hjälp av den skyfallskartering som tidigare gjorts identifierades de KPV som kan komma att drabbas vid ett 100- och 500-årsregn. Dessa utvärderades sedan genom en sårbarhetsanalys och en ekonomisk analys. Sårbarhetsanalysen syftade till att identifiera de byggnader som kan komma att drabbas värst samt en ekonomisk analys som beräknade de direkta kostnader som kan uppkomma vid ett extremt skyfall. Resultatet visar att det är två skolor i Bålsta, Fridegården och Potentiaskolan, som kan komma att bli de mest drabbade byggnaderna och att Centrumleden kan komma att bli opasserbar för räddningstjänsten vid ett 500-årsregn. Resultaten visar att de direkta kostnaderna för de KPV-klassade byggnaderna vid ett extremt skyfall kan uppgå till 2-4 miljoner kronor.

This study examines if it is possible to use pretrained neural models to make a detailed map in a set of case studies in Sweden. The models are taken from ESRI Living Atlas and are trained with data from the USA. The models are given orthophotos as input from three different parts of Sweden to make predictions from. The model results are combined to extract the best predictions of the presence of different object types and land cover classes, such as forests, open areas, lakes, roads and buildings. To enhance the map’s topographic details, a height model is employed, and certain features are added to mimic a conventional topographic map. A brief theoretical section elucidates the fundamentals of deep learning. Additionally, specific technical terms are defined and their application within the context of model usage and successful architectural designs is discussed. The performance metrics of the neural models are explained and subsequently applied in validating the results. The resulting map is validated versus an existing map provided by Lantmäteriet. The results are analyzed, and some shortcomings and advantages are highlighted and discussed. The final result shows that it is possible to make a detailed map based on automatic processes by combining the results of pretrained neural models. The map have some deviations relative the existing maps, the overall accuracy was 0.94, but the deviations seems smaller if you visually compared it with the ortofoto. The maps quality is at least of such good quality that it could serve a visual guide when making yourself a picture of chosen terrain in Sweden.

Ectomycorrhizal fungi contribute to weathering and may be used as an alternative to fertilizers. Their usefulness is dependent on how much they can contribute to the weathering that takes place in the same area. This review discusses the current literature on how much ectomycorrhizal fungi contribute to the total chemical weathering rate. There are few studies that document said contribution, with most geomycological weathering studies only reporting weathering numbers for the fungi. The weathering contribution towards apatite and olivine appears to be higher (at 28% and 16% respectively) than the 0.2% and 0.5% attributed to feldspar and 2% attributed to biotite. More research is needed to understand how much fungi can contribute to weathering. It would be preferable to study multiple species of both minerals and fungi at once in the same drainage area.

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