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  • 1.
    Entwistle, Jane A.
    et al.
    Department of Geography and Environmental Sciences, Northumbria University, Ellison Building, Newcastle upon Tyne NE1 8ST, UK.
    Amaibi, Patrick M.
    Department of Applied Sciences, Northumbria University, Ellison Building, Newcastle upon Tyne NE1 8ST, UK.
    Dean, John R.
    Department of Applied Sciences, Northumbria University, Ellison Building, Newcastle upon Tyne NE1 8ST, UK.
    Deary, Michael E.
    Department of Geography and Environmental Sciences, Northumbria University, Ellison Building, Newcastle upon Tyne NE1 8ST, UK.
    Medock, Daniel
    Toxicology Department, Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Chilton, Didcot, Oxon OX11 0RQ, UK.
    Morton, Jackie
    Health and Safety Executive, Harpur Hill, Buxton SK17 9JN, UK.
    Rodushkin, Ilia
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik. ALS Global Scandinavia, Aurorum 10, 977 75 Luleå, Sweden.
    Bramwell, Lindsay
    Institute of Health and Society, Medical Faculty, Newcastle University, Newcastle upon Tyne NE2 4AX, UK.
    An apple a day? Assessing gardeners' lead exposure in urban agriculture sites to improve the derivation of soil assessment criteria2019Ingår i: Environment International, ISSN 0160-4120, E-ISSN 1873-6750, Vol. 122, s. 130-141Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Globally, many of our urban agriculture sites (UAS) contain high levels of lead (Pb), a contaminant of toxicological concern to humans. To improve the derivation of soil assessment criteria at UAS, and avoid inappropriate closure of these valuable community spaces, we sampled nearly 280 paired soil and crop samples across 31 UAS gardens. This sampling was coupled with an exposure and food frequency questionnaire and participants blood Pb levels (BLL), (43 gardeners and 29 non-gardening neighbours). In 98% of the sampled soils, Pb concentrations were above the current UK soil guideline for UAS (80 mg/kg), however despite the high soil Pb (geometric mean: 324 mg/kg), and high soil bioaccessible Pb (geometric mean: 58.7%), all participants BLL were <4.1 μg/dL (range: 0.6–4.1 μg/dL). Indeed, there was no statistically significant difference between the BLL of the UAS gardeners and those of their non-gardening neighbours (p = 0.569).

    Pb uptake, however, varied with crop type and our study highlights the suitability of certain crops for growing at UAS with elevated Pb (e.g. tubers, shrub and tree fruit), whilst limiting the consumption of others (selected root vegetables, such as rhubarb, beetroot, parsnips and carrots, with observed Pb concentrations > 0.1 mg/kg FW).

    The importance of defining the exposure scenario of a specific sub-population (i.e. UAS gardeners) is highlighted. Our preferred models predict site specific assessment criteria (SSAC) of 722–1634 mg/kg. We found fruit and vegetable consumption rates by all participants, and not just the UAS gardeners, to be considerably higher than those currently used to derive the UK's category 4 screening levels (C4SLs). Furthermore, the soil to plant concentration factors (SPCFs) used to derive the UAS C4SL significantly over predict Pb uptake. Our study indicates it may be appropriate to develop a distinct exposure dataset for UAS. In particular we recommend the derivation of SPCFs that are reflective of urban soils, both in terms of the range of soil Pb concentrations typically observed, but also the sources (and hence human oral bioaccessibility and plant-availability) of this Pb.

  • 2.
    Boesen, Amanda H.
    et al.
    Department of Forestry and Wildlife Management, Faculty of Applied Ecology, Agricultural Sciences and Biotechnology, Inland Norway University of Applied Sciences, Koppang, Norway.
    Thiel, Alexandra
    Department of Forestry and Wildlife Management, Faculty of Applied Ecology, Agricultural Sciences and Biotechnology, Inland Norway University of Applied Sciences, Koppang, Norway.
    Fuchs, Boris
    Department of Forestry and Wildlife Management, Faculty of Applied Ecology, Agricultural Sciences and Biotechnology, Inland Norway University of Applied Sciences, Koppang, Norway.
    Evans, Alina L.
    Department of Forestry and Wildlife Management, Faculty of Applied Ecology, Agricultural Sciences and Biotechnology, Inland Norway University of Applied Sciences, Koppang, Norway.
    Bertelsen, Mads F.
    Center for Zoo and Wild Animal Health, Copenhagen Zoo, Frederiksberg, Denmark.
    Rodushkin, Ilia
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik. ALS Scandinavia AB.
    Arnemo, Jon M.
    Department of Forestry and Wildlife Management, Faculty of Applied Ecology, Agricultural Sciences and Biotechnology, Inland Norway University of Applied Sciences, Koppang, Norway. Department of Wildlife, Fish and Environmental Studies, Faculty of Forest Sciences, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Assessment of the LeadCare® Plus for Use on Scandinavian Brown Bears (Ursus arctos)2019Ingår i: Frontiers in Veterinary Science, ISSN 2297-1769, Vol. 6, artikel-id 285Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Lead (Pb) exposure is associated with adverse health effects in both humans and wildlife. Blood lead levels (BLL) of sentinel wildlife species can be used to monitor environmental lead exposure and ecosystem health. BLL analyzers, such as the LeadCare (R), are validated for use in humans, assessed for use in some avian species and cattle, and are increasingly being used on wildlife to monitor lead exposure. The LeadCare (R) analyzers use a technique called anodic stripping voltammetry (ASV). Species-specific conversion equations have been proposed to approximate the levels found with gold standard measuring methods such as inductively coupled plasma mass spectrometry (ICP-MS) because the ASV method has been shown to underestimate BLL in some species. In this study we assessed the LeadCare (R) Plus (LCP) for use on Scandinavian brown bears (Ursus arctos). LCP measurements were correlated with ICP-MS with a Bland-Altman analyzed bias of 16.3-22.5%, showing a consistent overestimation of BLL analyzed with LCP. Based on this analysis we provide conversion equations for calculating ICP-MS BLL based on the LCP results in Scandinavian brown bears. Our study shows that the LeadCare (R) Plus can be used for monitoring of lead exposure by approximating gold standard levels using conversion equations. This enables comparison with other gold standard measured BLL within the observed range of this study (38.20-174.00 mu g/L). Our study also found that Scandinavian brown bears are highly exposed to environmental lead.

  • 3.
    Liu, Jian-li
    et al.
    University of Science and Technology Beijing, Beijing, China.
    Yao, Jun
    China University of Geosciences (Beijing), China.
    Wang, Fei
    University of Science and Technology Beijing, Beijing, China.
    Min, Ning
    China University of Geosciences (Beijing), China.
    Gu, Ji-hai
    China University of Geosciences (Beijing), China.
    Li, Zi-fu
    University of Science and Technology Beijing, Beijing, China.
    Sunahara, Geoffrey
    China University of Geosciences (Beijing), China; McGill University, Montreal, Quebec,Canada.
    Duran, Robert
    China University of Geosciences (Beijing), China; Université de Pau et des Pays de l’Adour, Pau Cedex, France.
    Solevic-Knudsen, Tatjana
    University of Belgrade, Belgrade, Serbia.
    Hudson-Edwards, Karen A.
    University of Exeter, Penryn, Cornwall, UK.
    Alakangas, Lena
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Bacterial diversity in typical abandoned multi-contaminated nonferrous metal(loid) tailings during natural attenuation2019Ingår i: Environmental Pollution, ISSN 0269-7491, E-ISSN 1873-6424, Vol. 274, s. 98-107Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Abandoned nonferrous metal(loid) tailings sites are anthropogenic, and represent unique and extreme ecological niches for microbial communities. Tailings contain elevated and toxic content of metal(loid)s that had negative effects on local human health and regional ecosystems. Microbial communities in these typical tailings undergoing natural attenuation are often very poorly examined. The diversity and inferred functions of bacterial communities were examined at seven nonferrous metal(loid) tailings sites in Guangxi (China), which were abandoned between 3 and 31 years ago. The acidity of the tailings sites rose over 31 years of site inactivity. Desulfurivibrio, which were always coupled with sulfur/sulfide oxidation to dissimilate the reduction of nitrate/nitrite, were specific in tailings with 3 years abandonment. However, genus beneficial to plant growth (Rhizobium), and iron/sulfur-oxidizing bacteria and metal(loid)-related genera (Acidiferrobacter and Acidithiobacillus) were specific within tailings abandoned for 23 years or more. The increased abundance of acid-generating iron/sulfur-oxidizing and metal(loid)-related bacteria and specific bacterial communities during the natural attenuation could provide new insights for understanding microbial ecosystem functioning in mine tailings. OTUs related to Sulfuriferula, Bacillus, Sulfurifustis, Gaiella, and Thiobacillus genera were the main contributors differentiating the bacterial communities between the different tailing sites. Multiple correlation analyses between bacterial communities and geochemical parameters indicated that pH, TOC, TN, As, Pb, and Cu were the main drivers influencing the bacterial community structures. PICRUSt functional exploration revealed that the main functions were related to DNA repair and recombination, important functions for bacterial adaptation to cope with the multi-contamination of tailings. Such information provides new insights to guide future metagenomic studies for the identification of key functions beyond metal-transformation/resistance. As well, our results offers novel outlooks for the management of bacterial communities during natural attenuation of multi-contaminated nonferrous metal(loid) tailings sites. 

  • 4.
    Roqué Rosell, Josep
    et al.
    Department of Mineralogy, Petrology and Applied Geology, University of Barcelona, Barcelona, Catalunya, Spain.Institut de Nanociència i Nanotecnologia, IN2UB, Facultat de Química, Universitat de Barcelona, Barcelona, Catalunya, Spain..
    Portillo Serra, Joaquim
    Centres Científics i Tecnològics, Universitat de Barcelona, Barcelona, Catalunya, Spain.NanoMEGAS, Brussels, Belgium.
    Aiglsperger, Thomas
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Plana Ruiz, Sergi
    Institut de Nanociència i Nanotecnologia, IN2UB, Facultat de Química, Universitat de Barcelona, Barcelona, Catalunya, Spain.Institut für Angewandte Geowissenschaften, Technische Universität Darmstadt, Darmstadt, Germany.
    Pratim Das, Partha
    NanoMEGAS, Brussels, Belgium.
    Mendoza Gonzalvez, Joan
    Centres Científics i Tecnològics, Universitat de Barcelona, Barcelona, Catalunya, Spain.
    Trifonov, Trifon
    Centre de Recerca en Ciència i Enginyeria Multiescala de Barcelona, Universitat Politècnica de Catalunya (UPC), Catalunya , Sant Adrià de Besòs, Spain.
    Proenza, Joaquin Antonio
    Department of Mineralogy, Petrology and Applied Geology, University of Barcelona, Barcelona, Catalunya, Spain.Institut de Nanociència i Nanotecnologia, IN2UB, Facultat de Química, Universitat de Barcelona, Barcelona, Catalunya, Spain .
    Crystallographic information data of natural occurring zaccariniite (RhNiAs) obtained by means of precession electron diffraction2019Ingår i: Data in Brief, E-ISSN 2352-3409, Vol. 25, artikel-id 104346Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The crystal structure of naturally occurring zaccariniite (RhNiAs) has been studied in Transmission Electron Microscopy (TEM) with variable angle Precession Electron Diffraction (PED) techniques. The analysis of the data has yielded tetragonal cell parameters of 3.86, 3.86, 6.77 Å and space group of P4/nmm for the basic structure, and its constituent atom positions for Ni, As and Rh were determined as well by ab-initio structure resolution method. The data is related to “Structural characterization and ab-initio resolution of natural occurring zaccariniite (RhNiAs) by means of Precession Electron Diffraction” (Roqué Rosell et al., 2019).

  • 5.
    Benaiges-Fernandez, Robert
    et al.
    Department of Genetics, Microbiology and Statistics, Universitat de Barcelona, Barcelona, Catalonia, Spain. Institute of Environmental Assessment and Water Research (IDAEA, CSIC), Barcelona, Catalonia, Spain.
    Palau, Jordi
    Institute of Environmental Assessment and Water Research (IDAEA, CSIC), Barcelona, Catalonia, Spain. Department of Mineralogy, Petrology and Applied Geology, Universitat de Barcelona, Barcelona, Catalonia, Spain.
    Offeddu, Francesco G.
    Institute of Environmental Assessment and Water Research (IDAEA, CSIC), Barcelona, Catalonia, Spain.
    Cama, Jordi
    Institute of Environmental Assessment and Water Research (IDAEA, CSIC), Barcelona, Catalonia, Spain.
    Urmeneta, Jordi
    Department of Genetics, Microbiology and Statistics, Universitat de Barcelona, Barcelona, Catalonia, Spain. Biodiversity Research Institute (IRBio), Universitat de Barcelona, Barcelona, Catalonia, Spain.
    Soler, Josep M.
    Institute of Environmental Assessment and Water Research (IDAEA, CSIC), Barcelona, Catalonia, Spain.
    Dold, Bernhard
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik. Sustainable Mining Research & Consultancy EIRL, San Pedro de La Paz, Chile.
    Dissimilatory bioreduction of iron(III) oxides by Shewanella loihica under marine sediment conditions2019Ingår i: Marine Environmental Research, ISSN 0141-1136, E-ISSN 1879-0291Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Shewanella is a genus of marine bacteria capable of dissimilatory iron reduction (DIR). In the context of deep-sea mining activities or submarine mine tailings disposal, dissimilatory iron reducing bacteria may play an important role in biogeochemical reactions concerning iron oxides placed on the sea bed. In this study, batch experiments were performed to evaluate the capacity of Shewanella loihica PV-4 to bioreduce different iron oxides (ferrihydrite, magnetite, goethite and hematite) under conditions similar to those in anaerobic sea sediments. Results showed that bioreduction of structural Fe(III) via oxidation of labile organic matter occurred in all these iron oxides. Based on the aqueous Fe (II) released, derived Fe(II)/acetate ratios and bioreduction coefficients seem to be only up to about 4% of the theoretical ones, considering the ideal stoichiometry of the reaction. A loss of aqueous Fe (II) was caused by adsorption and mineral transformation processes. Scanning electron microscope images showed that Shewanella lohica was attached to the Fe(III)-oxide surfaces during bioreduction. Our findings suggest that DIR of Fe(III) oxides from mine waste placed in marine environments could result in adverse ecological impacts such as liberation of trace metals in the environment.

  • 6.
    Conrad, Sarah
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Ingri, Johan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Gelting, Johan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Nordblad, Fredrik
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Engström, Emma
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik. ALS Laboratory Group, ALS Scandinavia AB, Luleå, Sweden .
    Rodushkin, Ilia
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik. ALS Laboratory Group, ALS Scandinavia AB, Luleå, Sweden .
    Andersson, Per S.
    Department of Geosciences, Swedish Museum of Natural History, Stockholm, Sweden.
    Porcelli, Don
    Department of Earth Sciences, Oxford University, Oxford, UK.
    Gustafsson, Örjan
    Department of Environmental Science and Analytical Chemistry, Stockholm University, Stockholm, Sweden.
    Semiletov, Igor
    International Arctic Research Center (IARC), University of Alaska, Fairbanks, AK, USA. Pacific Oceanological Institute (POI), Far Eastern Branch of the Russian Academy of Sciences (FEBRAS), Vladivostok, Russia. Tomsk National Research Politechnical University, Arctic Seas Carbon International Research Laboratory, Tomsk, Russia.
    Öhlander, Björn
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Distribution of Fe isotopes in particles and colloids in the salinity gradient along the Lena River plume, Laptev Sea2019Ingår i: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 16, nr 6, s. 1305-1319Artikel i tidskrift (Refereegranskat)
    Abstract [en]

     Riverine Fe input is the primary Fe source for the ocean. This study is focused on the distribution of Fe along the Lena River freshwater plume in the Laptev Sea using samples from a 600 km long transect in front of the Lena River mouth. Separation of the particulate ( >  0.22 μm), colloidal (0.22 μm–1 kDa), and truly dissolved (<  1 kDa) fractions of Fe was carried out. The total Fe concentrations ranged from 0.2 to 57μM with Fe dominantly as particulate Fe. The loss of >  99% of particulate Fe and about 90% of the colloidal Fe was observed across the shelf, while the truly dissolved phase was almost constant across the Laptev Sea. Thus, the truly dissolved Fe could be an important source of bioavailable Fe for plankton in the central Arctic Ocean, together with the colloidal Fe. Fe-isotope analysis showed that the particulate phase and the sediment below the Lena River freshwater plume had negative δ56Fe values (relative to IRMM-14). The colloidal Fe phase showed negative δ56Fe values close to the river mouth (about -0.20 ‰) and positive δ56Fe values in the outermost stations (about +0.10 ‰). We suggest that the shelf zone acts as a sink for Fe particles and colloids with negative δ56Fe values, representing chemically reactive ferrihydrites. The positive δ56Fe values of the colloidal phase within the outer Lena River freshwater plume might represent Fe oxyhydroxides, which remain in the water column, and will be the predominant δ56Fe composition in the Arctic Ocean.

  • 7.
    Qureshi, Asif
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik. Quaid-e-Awam University of Engineering, Science and Technology, Nawabshah, Pakistan.
    Maurice, Christian
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Öhlander, Björn
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Effects of the co-disposal of lignite fly ash and coal mine waste rocks on AMD and leachate quality2019Ingår i: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 26, nr 4, s. 4104-4115Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Lignite fly ash (FA) and waste rocks (WRs) were mixed in three different ratios (1:1, 1:3 and 1:5) and studied to compare the effects of adding FA on acid mine drainage generation from coal mining WRs, leachability of elements and the potential occurrence of the secondary minerals. FA mixed with WRs showed significant differences in pH levels compared to previous research. The 1:1 mixture performed best of all the three mixtures in terms of pH and leachability of elements, mainly due to the higher proportion of FA in the mixture. The pH in the 1:1 mixtures varied between 3.3 and 5.1 compared to other mixtures (2.3–3.5). Iron and SO42− leached considerably less from the 1:1 mixture compared to the others, indicating that the oxidation of sulphides was weaker in this mixture. Aluminium leached to a high degree from all mixtures, with concentrations varying from mg L−1 to g L−1. The reason behind this increase is probably the addition of FA which, due to acidic conditions and the composition of the FA, increases the availability of Al. For the same reason, high concentrations of Mn and Zn were also measured. Geochemical modelling indicates that the 1:1 mixture performs better in terms of precipitation of Al3+ minerals, whereas Fe3+ minerals precipitated more in mixtures containing less FA. These results suggest that, with time, the pores could possibly be filled with these secondary minerals and sulphate salts (followed by a decrease in sulphide oxidation), improving the pore water pH and decreasing the leachability of elements. Since grain size plays a crucial role in the reactivity of sulphides, there is a risk that the results from the leaching tests may have been influenced by crushing and milling of the WR samples.

  • 8.
    Hellman, Maria
    et al.
    Swedish University of Agricultural Sciences, Department of Forest Mycology and Plant Pathology, Uppsala, Sweden.
    Bonilla-Rosso, Germán
    Swedish University of Agricultural Sciences, Department of Forest Mycology and Plant Pathology, Uppsala, Sweden.
    Widerlund, Anders
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Juhanson, Jaanis
    Swedish University of Agricultural Sciences, Department of Forest Mycology and Plant Pathology, Uppsala, Sweden.
    Hallin, Sara
    Swedish University of Agricultural Sciences, Department of Forest Mycology and Plant Pathology, Uppsala, Sweden.
    External carbon addition for enhancing denitrification modifies bacterial community composition and affects CH4 and N2O production in sub-arctic mining pond sediments2019Ingår i: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 158, s. 22-33Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Explosives used in mining operations release reactive nitrogen (N) that discharge into surrounding waters. Existing pond systems at mine sites could be used for N removal through denitrification and we investigated capacity in tailings and clarification pond sediments at an iron-ore mine site. Despite differences in microbial community structure in the two ponds, the potential denitrification rates were similar, although carbon limited. Therefore, a microcosm experiment in which we amended sediment from the clarification pond with acetate, cellulose or green algae as possible carbon sources was conducted during 10 weeks under denitrifying conditions. Algae and acetate treatments showed efficient nitrate removal and increased potential denitrification rates, whereas cellulose was not different from the control. Denitrifiers were overall more abundant than bacteria performing dissimilatory nitrate reduction to ammonium (DNRA) or anaerobic ammonium oxidation, although DNRA bacteria increased in the algae treatment and this coincided with accumulation of ammonium. The algae addition also caused higher emissions of methane (CH4) and nitrous oxide (N2O). The bacterial community in this treatment had a large proportion of Bacteroidia, sulfate reducing taxa and bacteria known as fermenters. Functional gene abundances indicated an imbalance between organisms that produce N2O in relation to those that can reduce it, with the algae treatment showing the lowest relative capacity for N2O reduction. These findings show that pond sediments have the potential to contribute to mitigating nitrate levels in water from mining industry, but it is important to consider the type of carbon supply as it affects the community composition, which in turn can lead to uwanted processes and increased greenhouse gas emissions.

  • 9.
    Karlsson, Teemu
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik. Geological Survey of Finland GTK.
    Geochemical and mineralogical laboratory methods in waste rock drainage quality prediction2019Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Harmful substances containing acid or neutral rock drainages (ARD and NRD) are a major challenge related to the management of extractive industry wastes. This issue is particularly related to deposits containing sulphide minerals, which are prone to oxidization under the influence of atmospheric oxygen and water. The drainage quality depends mainly on the mineralogical and chemical composition of the extractive wastes, and especially on the ratio of acid-producing and neutralizing minerals, combined with reactions catalysed by microbes. Since harmful drainages play a major role in the generation of environmental issues for extractive industry, the accurate prediction of the drainage quality is of utmost importance. To design appropriate extractive waste facilities and drainage management, the characterisation of extractive wastes and assessment of the behaviour of the waste material is essential already before the actual mining activities start.

    Several methods have been developed to characterize extractive waste materials and to predict their short and long term behaviour, including e.g. geochemical laboratory tests, static tests and longer term kinetic tests, and geochemical modelling. The characterisation methods for assessing the ARD risk can be divided into static and kinetic tests. Static tests are short term laboratory analyses, usually used for preliminary investigation and screening. Kinetic tests are longer term tests, revealing information on the time scale of drainage events. Commonly used static tests for ARD prediction include acid–base accounting (ABA) tests and the net acid generation (NAG) test. Since acid and neutralisation potential largely depend on the ratio and quality of acid-producing and neutralizing minerals, mineralogical calculations could also be used for ARD prediction. The mobility of potentially harmful substances from extractive waste can be preliminary assessed using different geochemical laboratory tests, including selective extraction and leaching methods. The most commonly used selective extraction method in Finland is the aqua regia (AR) extraction. In addition to some silicates and secondary precipitate minerals, it is intended to dissolve elements bound especially to sulphide phases. A less commonly used method for element mobility prediction is the analysis of the single addition NAG test leachate.

    In this study, several Finnish waste rock sites were investigated and the performances of different preliminary drainage quality test methods evaluated and compared. The assessed acid production potential methods included the ABA test as presented in the standard EN 15875, the single addition NAG test as presented in the AMIRA guidebook, and a SEM mineralogy-based calculation. The assessed methods for element mobility prediction included the single addition NAG test leachate analysis and the AR extraction.

    According to the results, pyrrhotite seems to be the main mineral contributing to acid production, and the silicate minerals the main contributors to the neutralisation potential at the most Finnish waste rock sites. Since silicate minerals appear to have a significant role in ARD prevention, the behaviour of these minerals in mining environment should be more thoroughly investigated. In the investigated Finnish waste rocks, Co, Cr, Cu and Ni often occurred as elevated concentrations, and the most widely abundant harmful elements in the waste rock drainages were Co, Cu, Ni and Zn. The results suggest that an acid production prediction based on SEM mineralogical calculation is at least as accurate as the commonly used static laboratory methods. The AR extraction indicates well which elements might occur as elevated concentrations in the drainage. Also the NAG test leachate analysis performed well in element mobility assessment, but only when the NAG test leachate was sufficiently acidic, the leachate pH being below of 3-6, depending on the element of interest.

  • 10.
    Jia, Yu
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik. Department of Environment and Mineral Resources Greenland Institute of Natural Resources Nuuk.
    Stahre, Nanna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik. School of Science and Technology, Örebro University.
    Maurice, Christian
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik. Ramböll Sverige AB Luleå.
    Öhlander, Björn
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Geotechnical and chemical characterization of field-applied fly ash as sealing material over mine tailings2019Ingår i: International Journal of Environmental Science and Technology, ISSN 1735-1472, E-ISSN 1735-2630, Vol. 16, nr 3, s. 1701-1710Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The present study addresses the geotechnical and chemical properties of sealing materials using a paper mill by-product, fly ash, on top of sulfide-bearing mine waste tailings after 5 years of field application. From a geotechnical perspective, the low in situ bulk density (≤ 1500 kg/m3) ensured a high degree of water saturation (90.2%) for the field-applied ash. The chemical characteristics and behaviors of the fly ash samples reflected a high long-term leaching capacity (liquid-to-solid ratio of 10 cm3/g) and high alkalinity (liquid-to-solid ratio of up to 500 cm3/g). The laboratory leaching results suggested that none of the elements released from the field-applied ash exceeded the EU limits for inert materials, and the concentrations of elements were far below the limits for hazardous materials at landfill sites. Based on the in situ and laboratory characterizations of the field-applied ash, the fly ash sealing material was considered geotechnically stable. However, a number of geotechnical parameters could not be measured due to the cementation of the ash. Moreover, the chemical composition of the field-applied ash exhibited considerable variations when compared with that of the raw ash generated from the same paper mill. Overall, the field-applied ash displayed high alkalinity and effectively buffered the acid generated from sulfidic tailings for long-term sealing purposes.

  • 11.
    Kaasalainen, Hanna
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik. Sweco Environment, Luleå, Sweden.
    Lundberg, Paula
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Aiglsperger, Thomas
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Alakangas, Lena
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Impact of declining oxygen conditions on metal(loid) release from partially oxidized waste rock2019Ingår i: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 26, nr 20, s. 20712-20730Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The best available technology for preventing the formation of acid drainage water from the sulfidic waste rock at mine closure aims to limit the oxygen access to the waste. There is, however, a concern that contaminants associated with secondary minerals become remobilized due to changing environmental conditions. Metal(loid) mobility from partially oxidized sulfidic waste rock under declining and limited oxygen conditions was studied in unsaturated column experiments. The concentrations of sulfate and metal(loid)s peaked coincidently with declining oxygen conditions from 100 to < 5 sat-% and to a lesser extent following a further decrease in the oxygen level during the experiment. However, the peak concentrations only lasted for a short time and were lower or in the similar concentration range as in the leachate from a reference column leached under atmospheric conditions. Despite the acid pH (~ 3), the overall quality of the leachate formed under limited oxygen conditions clearly improved compared with atmospheric conditions. In particular, the release of As was two orders of magnitude lower, while cationic metals such as Fe, Cu, Mn, and Zn also decreased, although to a lesser extent. Decreased sulfide oxidation is considered the primary reason for the improved water quality under limited oxygen conditions. Another reason may be the immobility of Fe with the incorporation of metal(loid)s in Fe(III) minerals, in contrast to the expected mobilization of Fe. The peaking metal(loid) concentrations are probably due to remobilization from solid Fe(III)-sulfate phases, while the relatively high concentrations of Al, Mn, and Zn under limited oxygen conditions were due to release from the adsorbed/exchangeable fraction. Despite the peaking metal(loid) concentrations during declining oxygen conditions, it is clear that the primary remediation goal is to prevent further sulfide oxidation.

  • 12.
    Conrad, Sarah
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Iron isotopes in aquatic systems2019Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The cycling of iron (Fe) is a key component for understanding water quality and biogeochemical processes. It serves as mediator during biotic and abiotic processes, as electron acceptor during the degradation of organic matter, as surface for trace element and organic matter adsorption, and is necessary for primary production processes. Since the beginning of Fe isotope studies, researchers focussed on the ratios in soils, rivers and oceans in various environments. The aim of this study was to characterize the Fe isotope ratios from the source (e.g. soils), along the river course, through the estuaries and into the adjacent sea within the boreal landscape. Therefore, seasonal sampling of water from Swedish headwater streams (2016/2017), rivers (2016), estuaries (2013/2014) and the Baltic Sea (2013/2014) were conducted, with the purpose to better understand the role and fate of riverine Fe export. Fe is transported in two main phases from the headwater streams into the oceans: organic Fe complexes and Fe(oxy)hydroxide. It has been proposed that these Fe phases varies in response to seasonal differences in hydrology.

                          This thesis includes the first Fe isotope dataset describing seasonal variations of headwater streams on a regional scale. In the headwater streams positive and negative Fe isotopes ratios can be used to distinguish between different Fe phases. Furthermore, Fe isotope ratios in headwater streams could verify regional drought periods and the subsequent rewetting of the subsurface soils.

    Within the rivers and estuaries, we found positive Fe isotopes in the dissolved phase (< 0.22µm) and negative Fe isotopes (> 0.22µm) in the particulate phase during high discharge. The correlation between different chemical parameters, Fe and DOC showed that the Fe isotope composition during spring flood is evolving in the upper soil layers of headwater streams. Therefore, the lighter Fe isotope signal is correlated to the organic-rich soil layers of the riparian zones in forested catchments. During baseflow, particulate Fe has a positive Fe isotope signal. This shows that the Fe has different origin throughout the season within one catchment.

    Salt-induced flocculation in the estuaries and under experimental conditions, is removing about 80 % of the dissolved and particulate Fe. Newly formed colloids and particles aggregate and sediment due to small changes in salinity. This major flocculation at low salinities might cause an underestimation of riverine Fe flux. Interestingly, salinity-induced aggregation experiments revealed that Fe(oxy)hydroxide, which dominated aggregates, displayed lower Fe isotope ratios than in the river samples Fe, while organic Fe complexes in the suspension had higher Fe isotope values. The seasonal variability in Fe isotope values could not be simply linked to Fe phases but was probably also influenced by variation in source areas of Fe and processes along the flow-path that alter both Fe phases and isotopic composition.

    Within the estuarine mixing zone, no Fe isotope fractionation was observed. The Fe isotope signal is constant over time and space, which excludes fractionation processes for example by oxidation. The Fe isotope signal within the Bothnian Bay was positive showing that different surface properties of Fe-OC and Fe(oxy)hydroxide aggregates lead to the flocculation of negative Fe aggregates.

  • 13.
    Alakangas, Lena
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Salifu, Musah
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Rasmussen, Thorkild Maack
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Heino, Neea
    Geological Survey of Finland, Finland.
    Hyvönen, Eija
    Geological Survey of Finland, Finland.
    Karlsson, Teemu
    Geological Survey of Finland, Finland.
    Panttila, Hannu
    Geological Survey of Finland, Finland.
    Pietilä, Raija
    Geological Survey of Finland, Finland.
    Tornivaara, Anna
    Geological Survey of Finland, Finland.
    Turunen, Kaisa
    Geological Survey of Finland, Finland.
    Lu, Jinmei
    UiT The Arctic University of Norway, Norway.
    Fu, Shuai
    UiT The Arctic University of Norway, Norway.
    Bui, Minh Tuan
    UiT The Arctic University of Norway, Norway.
    Heiderscheidt, Elisangela
    University of Oulu, Finland.
    Postila, Heini
    University of Oulu, Finland.
    Leiviskä, Tiina
    University of Oulu, Finland.
    Ronkanen, Anna-kaisa
    University of Oulu, Finland.
    Kujala, Katharina
    University of Oulu, Finland.
    Khan, Uzair
    University of Oulu, Finland.
    Gogoi, Harshita
    University of Oulu, Finland.
    Min-North: Development, Evaluation and Optimization of Measures to Reduce the  Environmental Impact of Mining Activities in Northern Regions2019Rapport (Övrigt vetenskapligt)
    Abstract [en]

    The Min-North (Development, Evaluation and Optimization of Measures to Reduce the Environment Impact of Mining Activities in Northern Regions) project was a trans-national cooperative project, with participants from the Geological Survey of Finland (GTK), University of Oulu (UO), UiT The Arctic University of Norway (UiT), Luleå University of Technology (LTU) and SMEs from Sweden, Finland and Norway. The project was funded by Interreg Nord and Norrbottens länsstyrelse. The participants have expertise in mine waste management, mine water treatment and geophysics. The overall aim of the project was to enhance the development of environmental protection technologies. An associated goal was to deepen cross-border cooperation by creating a larger critical mass of researchers in mine waste management and local SMEs in the Northern regions with greater capacities to disseminate and implement new methods, products and services. The project ran for 36 months from the 1st of January 2016 to the end of December 2018.

     

  • 14.
    Murray, Jesica
    et al.
    Instituto de Bio y Geo Ciencias del Noroeste Argentino, Universidad Nacional de Salta - CONICET, 4405 Rosario de Lerma, Argentina. Laboratoire d'Hydrologie et de Géochimie de Strasbourg, Université de Strasbourg, EOST, CNRS, Strasbourg, France.
    Nordstrom, Darrell Kirk
    United States Geological Survey, Boulder, CO, United States of America.
    Dold, Bernhard
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Orué, Maria Romero
    Instituto de Bio y Geo Ciencias del Noroeste Argentino, Universidad Nacional de Salta - CONICET, Rosario de Lerma, Argentina.
    Kirschbaum, Alicia
    Instituto de Bio y Geo Ciencias del Noroeste Argentino, Universidad Nacional de Salta - CONICET, Rosario de Lerma, Argentina.
    Origin and geochemistry of arsenic in surface and groundwaters of Los Pozuelos basin, Puna region, Central Andes, Argentina2019Ingår i: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 697, artikel-id 134085Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Los Pozuelos is a closed basin in the Puna region of NW Argentina, Central Andes. This is a semi-arid region where closed basins are the most important feature for the hydrologic systems. The center of the basin is occupied by a fluctuating playa lake called Los Pozuelos lagoon, which constitutes a UNESCO Biosphere Reserve. This is one of the most populated closed basins in the Argentinian Puna and residents use groundwater for drinking and cooking. Lowest concentrations of As and dissolved solids are in the headwaters of the rivers (1.46–27 μg/L) and the highest concentrations are in the lagoon (43.7–200.3 μg/L). In groundwater, arsenic concentrations increase from the outer ring aquifer (3.82–29.7 μg/L) composed of alluvial-alluvial fan sediments to the inner lacustrine aquifer (10–113 μg/L) that surround the playa lake. Moreover, high concentrations of As during the dry season (90.2 and 113 μg/L), Na/K mass ratios (0.2 and 0.3), and formation of Na-rich efflorescent salts suggest that high evaporation rates increases As concentration, while rainwater dilutes the concentration during the wet season. As(V) is the dominant species in all the water types, except for the lagoon, where As(III) occasionally dominates because of organic matter buildup. There are at least three potential sources for As in water i) oxidation of As sulfides in Pan de Azúcar mine wastes, and acid mine drainage discharging into the basin; ii) weathering and erosion of mineralized shales; iii) weathering of volcanic eruptive non-mineralized rocks. Because it is a closed basin, the arsenic released from the natural and anthropogenic sources is transported in solution and in fluvial sediments and finally accumulates in the center of the basin where the concentration in water increases by evaporation with occasional enhancement by organic matter interaction in the lagoon.

  • 15.
    Nyström, Elsa
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Kaasalainen, Hanna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Alakangas, Lena
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Prevention of sulfide oxidation in waste rock by the addition of lime kiln dust2019Ingår i: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 26, nr 25, s. 25945-25957Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    During the operation of a mine, waste rock is often deposited in heaps and usually left under ambient conditions allowing sulfides to oxidize. To focus on waste rock management for preventing acid rock drainage (ARD) formation rather than ARD treatment could avoid its generation and reduce lime consumption, costs, and sludge treatment. Leachates from 10 L laboratory test cells containing sulfide-rich (> 60% pyrite) waste rock with and without the addition of lime kiln dust (LKD) (5 wt.%) were compared to each other to evaluate the LKD’s ability to maintain near neutral pH and reduce the sulfide oxidation. Leaching of solely waste rock generated an acidic leachate (pH < 1.3) with high concentrations of As (21 mg/L), Cu (20 mg/L), Fe (18 g/L), Mn (45 mg/L), Pb (856 μg/L), Sb (967 μg/L), S (17 g/L), and Zn (23 mg/L). Conversely, the addition of 5 wt.% LKD generated and maintained a near neutral pH along with decreasing of metal and metalloid concentrations by more than 99.9%. Decreased concentrations were most pronounced for As, Cu, Pb, and Zn while S was relatively high (100 mg/L) but decreasing throughout the time of leaching. The results from sequential extraction combined with element release, geochemical calculations, and Raman analysis suggest that S concentrations decreased due to decreasing sulfide oxidation rate, which led to gypsum dissolution. The result from this study shows that a limited amount of LKD, corresponding to 4% of the net neutralizing potential of the waste rock, can prevent the acceleration of sulfide oxidation and subsequent release of sulfate, metals, and metalloids but the quantity and long-term stability of secondary minerals formed needs to be evaluated and understood before this method can be applied at a larger scale.

  • 16.
    Herzog, Simon D.
    et al.
    Department of Science and Environment, Roskilde University, Roskilde, Denmark.
    Conrad, Sarah
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Ingri, Johan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Persson, Per
    Centre for Environmental and Climate Research & Department of Biology, Lund University, Lund, Sweden.
    Kritzberg, Emma S.
    Department of Biology/Aquatic Ecology, Lund University, Lund, Sweden.
    Spring flood induced shifts in Fe speciation and fate at increased salinity2019Ingår i: Applied Geochemistry, ISSN 0883-2927, E-ISSN 1872-9134, Vol. 109, artikel-id 104385Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Rivers have traditionally been viewed as negligible sources of iron (Fe) to marine waters, as most Fe gets lost during estuarine mixing. However, recent findings demonstrate that Fe from boreal rivers display a higher resistance towards salinity-induced aggregation, presumably due to stabilizing interactions with organic matter. Previous studies have shown that Fe (oxy)hydroxides are selectively removed by aggregation processes, and that organic Fe complexes are less affected by increasing salinity. It has been further proposed that Fe speciation varies in response to seasonal differences in hydrology. In this study X-ray absorption spectroscopy (XAS) was used to determine the temporal variation in Fe speciation and the connection to Fe stability in response to increasing salinity in two boreal rivers (Kalix and Råne River), with the purpose to better understand the fate of riverine Fe export. Sampling was done from winter pre-flood, over the spring flood, to post-flood conditions (early April until mid June). In addition, parallel analyses for Fe speciation and isotope composition (δ56Fe relative to IRMM-14) were made on river samples, as well as salinity-induced aggregates and the fraction remaining in suspension, with the main objective to test if δ56Fe reflect the speciation of Fe.

    The contribution of organically complexed Fe increased during spring flood compared to the pre- and post-flood, as did Fe transport capacity. However, since Fe (oxy)hydroxides were dominating throughout the sampling period, the seasonal variability was small. Interestingly, salinity-induced aggregation experiments revealed that Fe (oxy)hydroxides, which dominated aggregates, displayed lower δ56Fe than in the river samples Fe, while organic Fe complexes in suspension had higher δ56Fe values. The seasonal variability in Fe isotope signature could not be simply linked to Fe speciation, but was probably also influenced by variation in source areas of Fe and processes along the flow-path that alter both Fe speciation and isotopic composition.

  • 17.
    Salifu, Musah
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Aiglsperger, Thomas
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Mörth, Carl-Magnus
    Department of Geological Sciences, Stockholm University, Stockholm, Sweden.
    Alakangas, Lena
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Stable sulphur and oxygen isotopes as indicators of sulphide oxidation reaction pathways and historical environmental conditions in a Cu–W–F skarn tailings piles, south-central Sweden2019Ingår i: Applied Geochemistry, ISSN 0883-2927, E-ISSN 1872-9134, Vol. 110, artikel-id 104426Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Improved remediation strategies or predictive modelling of acid mine drainage (AMD) sites, require detailed understanding of the sulphide oxidation reaction pathways, as well as pollutant-source characterisation. In this study, ore minerals, solids and water-soluble fractions of an oxidising Cu–W–F skarn tailings in Yxsjöberg, Sweden, were chemically and isotopically (δ34S and δ18O) characterised to reveal sulphate (SO42−) sources, sulphide oxidation reaction pathways and historical environmental conditions in the tailings. δ34S was additionally used to trace the weathering of danalite [(Fe,Mn,Zn)4Be3(SiO4)3S], a rare and unstable sulphur-bearing silicate mineral containing high concentrations of beryllium (Be) and zinc (Zn). Eighteen subsamples from a drill core of the tailings were subjected to batch leaching tests to obtain water-soluble fractions, which reflected both existing pore-waters and easily-soluble secondary minerals. The tailings were categorised into three geochemical zones: (i) oxidised zone (OZ), (ii) transition zone (TZ) and (iii) unoxidised zone (UZ), based on prevailing pH, elemental concentrations and colour. The upper OZ (UOZ) showed a sharp depletion of sulphur (S) and relatively higher δ18OSO4 values (−3.0 to +0.1‰) whereas the underlying lower OZ (LOZ) showed S accumulation and lower δ18OSO4 values (−4.6 to −4.2‰). The higher δ18OSO4 suggested the role of atmospheric oxygen, O2 (as oxidant), contribution of evaporated rainwaters and/or evaporation in the upper zones of the tailings. The lower δ18OSO4 values were indicative of ferric iron (Fe3+) as oxidant and the possible incorporation of 16O into SO42− during its formation, most probably from snow melt or depleted rainwater. The δ34SSO4 values in the OZ (+2.3 to +2.4‰) suggested SO42− from pyrrhotite oxidation in the UOZ which has been subsequently mobilised to the LOZ. Low δ34S fractionation (+0.2 to +1.9‰) between SO42− in the OZ and pyrrhotite, as well as the low δ18OSO4 values in the LOZ suggested the complete oxidation of pyrrhotite by Fe3+, signalling that previously, a low pH (<3) prevailed in the tailings. Mineralogical observations confirmed that pyrrhotite was completely oxidised in the UOZ, with the formation of hydrous ferric oxides (HFOs) coatings. The observed current high δ18OSO4 and pH (3.9–4.5) values in the UOZ were attributed to decreased oxidation rate and silicate buffering, limiting the availability of aqueous Fe3+ and subsequent formation of HFOs. The δ34SSO4 signatures of the water-soluble SO42− in the TZ and UUZ suggested the dissolution of gypsum which precipitated from a leachate from the weathering of danalite in the UOZ. In the middle UZ, the δ34SSO4 (−0.8 to +0.6‰) and δ18OSO4 (−1.8 to −1.0‰) signatures corresponded to SO42− from a mixture of pyrite, pyrrhotite and chalcopyrite oxidation by O2 at the LOZ (i.e. oxidation front). Negative δ34S fractionation values (−3.0 to −1.6‰) between these minerals and the water-soluble SO42− were attributed to the potential formation of intermediate S species, due to the partial oxidation of the sulphides. Consequently, the S accumulation in the LOZ could be due to the likely formation of the intermediate S species and secondary pyrite identified in this zone. The lower UZ coincided with the groundwater table and registered consistent negative δ34SSO4 (−2.6 to −1.8‰) and δ18OSO4 (−7.6 to −4.4‰) values. These signatures were hypothesised to be controlled by SO42− from the mineralisation of organic S in peat underneath the tailings and/or H2S oxidation, with possible contribution from sulphide oxidation in the tailings. This study highlights the usefulness of δ34S and δ18O as tracers of geochemical processes and environmental conditions that have existed in the tailings.

  • 18.
    Alakangas, Lena
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Hanna, Kaasalainen
    Sweco.
    Maurice, Christian
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Nyström, Elsa
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Nigéus, Susanne
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    StopOx: Utilization Of Industrial Residuals For Prevention Of Sulfide Oxidation In Mine Waste2019Rapport (Övrigt vetenskapligt)
    Abstract [en]

    This report is the outcome of the SIP STRIM project

    StopOx-Utilization of industrial residuals for prevention of sulfide oxidation in mine waste implemented at Applied geochemistry, Luleå University of Technology running from 2015 to 2018. Boliden Mineral has been partner and co-funder of the project. Other partners in the project were Cementa, Dragon Mining, MEROX, Nordkalk, and SP Processum. The overall aim of the project was to develop prevention technologies to reduce the sulfide oxidation in mine waste, during and after operation, and thereby reduce the generation of acid mine drainage. The StopOx project has been focusing on sulfidic mine waste from the Boliden area which were disposed of and are causing acid mine drainage or have the potential. Industrial residues/products were supplied by BillerudKorsnäs, Cementa, MEROX, and Nordkalk. The report consists of chapters based on three subprojects.

    Chapter 1. Introduction

    Chapter 2. Inhibition technology with aim to minimize waste rock oxidation during operations by using residues from other industries (passivation of sulfidic surfaces by the formation of secondary minerals)

    Chapter 3. The suitability of green liquor dregs as substitutes for or additives to till in a sealing layer as part of a cover system

    Chapter 4. Weathering of waste rock under changing chemical conditions

    The research described in chapters 2 and 3 was performed by Ph.D. students and will continue until 2021, while the subproject in chapter 2 ended in 2018.

  • 19.
    Roqué Rosell, Josep
    et al.
    Department of Mineralogy, Petrology and Applied Geology, University of Barcelona, Barcelona, Catalunya, Spain.Institut de Nanociència i Nanotecnologia, IN2UB, Facultat de Química, Universitat de Barcelona, Barcelona, Catalunya, Spain..
    Portillo Serra, Joaquim
    Centres Científics i Tecnològics, Universitat de Barcelona, Barcelona, Catalunya, Spain.NanoMEGAS, Brussels, Belgium.
    Aiglsperger, Thomas
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Plana Ruiz, Sergi
    Institut de Nanociència i Nanotecnologia, IN2UB, Facultat de Química, Universitat de Barcelona, Barcelona, Catalunya, Spain.Institut für Angewandte Geowissenschaften, Technische Universität Darmstadt, Darmstadt, Germany.
    Pratim Das, Partha
    NanoMEGAS, Brussels, Belgium.
    Mendoza Gonzalvez, Joan
    Centres Científics i Tecnològics, Universitat de Barcelona, Barcelona, Catalunya, Spain.
    Trifonov, Trifon
    Centre de Recerca en Ciència i Enginyeria Multiescala de Barcelona, Universitat Politècnica de Catalunya (UPC), Catalunya , Sant Adrià de Besòs, Spain.
    Proenza, Joaquin Antonio
    Department of Mineralogy, Petrology and Applied Geology, University of Barcelona, Barcelona, Catalunya, Spain.Institut de Nanociència i Nanotecnologia, IN2UB, Facultat de Química, Universitat de Barcelona, Barcelona, Catalunya, Spain .
    Structural characterization and ab-initio resolution of natural occurring zaccariniite (RhNiAs) by means of Precession Electron Diffraction2019Ingår i: Microchemical journal (Print), ISSN 0026-265X, E-ISSN 1095-9149, Vol. 148, s. 130-140Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The crystal structure of naturally occurring zaccariniite from Loma Peguera (Republica Dominicana) has been studied in Transmission Electron Microscopy(TEM) with variable angle Precession Electron Diffraction (PED) techniques: 0.7° Precession Electron Diffraction Tomography (Precession EDT) for unit cell and Laue class sorting, 0.5° Scanning Precession Diffraction (SPED) for crystal orientation mapping and grain alignment, and high symmetry zone axis 1.2° to 2.2° Zone Axis High Angle Precession Electron Diffraction (ZA high angle PED) for Space Group assessment and supercell information gathering. The natural sample has been prepared into an electron thin lamella by means of Focused Ion Beam(FIB). The analysis of the data has yielded tetragonal cell parameters of 3.86, 3.86, 6.77 Å and space group of P4/nmm for the basic structure, and its constituent atom positions for Ni, As and Rh were determined as well by ab-initio structure resolution method in accordance to the elemental composition of the natural zaccariniite obtained with Energy Dispersive X-ray (EDX) and High Magnification Electron Microscopy (HMEM) analysis. A modulation of the crystal basic structure of 3 by 1 in the basal plane has been reported for the first time on natural occurring zaccariniite.

  • 20.
    Nyström, Elsa
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Kaasalainen, Hanna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Alakangas, Lena
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Suitability study of secondary raw materials for prevention of acid rock drainage generation from waste rock2019Ingår i: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 232, s. 575-586Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Prevention and mitigation of acid rock drainage (ARD) from mine wastes are crucial for limiting environmental impact. However, preventive measures are often too expensive, potentially harmful to the environment or not applied early enough. This study aimed to test the potential of different secondary raw materials for maintaining a circumneutral pH (6–7) in a sulfide oxidation environment, allowing secondary minerals to form on reactive sulfide surfaces to prevent release of acid, metals and metalloids, and thereby ARD generation. Five materials (blast furnace slag, granulated blast furnace slag, cement kiln dust, bark ash, lime kiln dust) were selected based on their alkaline properties, availability and yearly yield. High sulfidic (>50 wt%, sulfide) waste rock from an active Cu–Zn–Au–Ag open pit mine in northern Sweden was leached in small-scale laboratory test cells under ambient condition for 4–8 weeks before adding secondary raw materials on the surface in an attempt to prevent ARD generation. During 52 subsequent weeks of leaching, the pH and electrical conductivity in the leachate from the waste rock varied between 1.7-4.6 and 2.1–22.8 mS/cm, respectively. All secondary raw materials were able to increase the pH to circumneutral. However, blast furnace slag, granulated blast furnace slag and cement kiln dust were not able to maintain a circumneutral pH for an extended time due to self-cementation or carbonation, whereas bark ash (1 wt%) and lime kiln dust (5 wt%) prevented acidity, metal and metalloid leaching. Materials such as cement kiln dust and bark ash contained elevated concentrations of, e.g., Cd and Zn, but the release of metals and metalloids was generally low for most elements, except for Cl, K and Na, most likely due to salt dissolution.

  • 21.
    Filella, Montserrat
    et al.
    Department F.-A. Forel, University of Geneva, Geneva, Switzerland..
    Reimann, Clemens
    Geological Survey of Norway, Trondheim, Norway..
    Biver, Marc
    Bibliothèque Nationale de Luxembourg, Luxembourg, Luxembourg.
    Rodushkin, Ilia
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik. ALS Laboratory Group, ALS Scandinavia AB, Luleå, Sweden..
    Rodushkina, Katerina
    ALS Laboratory Group, ALS Scandinavia AB, Luleå, Sweden.Ghent University, Department of Chemistry, Atomic and Mass Spectrometry Research Group, Campus Sterre, Ghent, Belgium.
    Tellurium in the environment: current knowledge and identification of gaps2019Ingår i: Environmental Chemistry, ISSN 1448-2517, E-ISSN 1449-8979, Vol. 16, nr 4, s. 215-228Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Tellurium has recently become a ‘technology-critical element’ increasingly used in new applications. Thus, potential environmental impacts need to be evaluated. This, in turn, requires knowledge of its typical concentrations in the environment along with better understanding of the chemical processes governing its environmental behaviour. We evaluate the current situation of our understanding of tellurium in the environment and identify the areas where improvements in measurement technology are most needed. The comprehensive evaluation of published data described in this study shows that values for tellurium concentrations in the different environmental compartments are scarce, particularly in the case of natural waters where reliable estimates of tellurium concentrations in seawater and freshwater cannot even be produced. Data in air are even less abundant than for natural water. Concentration data do exist for soils suggesting a predominant geological origin. Some urban soil surveys and lake sediment data close to tellurium contamination sources point to possible effects on the element’s distribution as a result of human activity; long-range atmospheric transport remains to be proved. Current knowledge about tellurium behaviour in the environment is strongly hindered by analytical difficulties, with insufficiently low analytical detection limits being the main limitation. For instance, ‘dissolved’ concentrations are well below current analytical capabilities in natural water and often require pre-concentration procedures that, for the moment, do not provide consistent results; solid samples require complex mineralisation procedures that often exclude tellurium from routine multielement studies. In general, the use of available measuring techniques is far from straightforward and needs particular expertise. Overcoming the current analytical limitations is essential to be able to progress in the field.

  • 22.
    Jia, Yu
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik. Department of Environment and Minerals ResourcesGreenland Institute of Nature ResourcesNuukGreenland.
    Hamberg, Roger
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik. Swedish Geological Survey AB, Luleå, Sweden.
    Qureshi, Asif
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik. Department of Energy and Environment Engineering, Quaid-e-Awam University of Engineering, Science & Technology, Nawabshah, Pakistan.
    Mäkitalo, Maria
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Maurice, Christian
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik. Ramböll Sverige AB, Luleå, Sweden.
    Variation of green liquor dregs from different pulp and paper mills for use in mine waste remediation2019Ingår i: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The geotechnical, chemical, and mineralogical properties of green liquor dregs (GLDs) generated as byproducts from five paper mills were investigated to assess their buffering and heavy metal immobilization capacities and their roles as water and oxygen barriers. One type of GLD was further studied to test the effects of the retrieval process and the storage, drying, and hydration of GLD. The high water retention capacity of the GLDs is valuable for limiting O2diffusion. Laboratory results showed that the GLDs had hydraulic conductivities of 3.7 × 10−9–4.6 × 10−8 m/s and varied regularly in plasticity. The chemical and mineralogical compositions of the GLDs varied greatly, reflecting the raw material used to produce paper and the process used to retrieve GLDs. Although they had high total heavy metal contents, none of the leached elements from the GLDs (L/S 10 cm3/kg) exceeded the European Union’s limits for landfills of non-hazardous waste. The GLDs exhibited high buffering capacities. In a supplementary test, the buffering capacities varied (0.0041–0.0114 M H+/g GLD) over 72 d after acid was added to the GLD. Changing the filtration process did not greatly affect the GLDs’ properties but mainly affected the hydraulic conductivity, total heavy metal contents and sulfur content. Analyzing the storage of GLDs is necessary in the mining industry because remediation measures require large amounts of material over short periods. The buffering capacity of the dried GLD decreased slightly. The effect of dewatering caused by the mixing of 2% Na-lignosulfate with GLD (w/w) was low.

  • 23.
    Filella, Montserrat
    et al.
    Department F.-A. Forel, University of Geneva.
    Rodushkin, Ilia
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    A concise guide for the determination of less-studied technology-critical elements (Nb, Ta, Ga, In, Ge, Te) by inductively coupled plasma mass spectrometry in environmental samples2018Ingår i: Spectrochimica Acta Part B - Atomic Spectroscopy, ISSN 0584-8547, E-ISSN 1873-3565, Vol. 141, s. 80-84Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    There is an increasing demand for analytical techniques able to measure so-called ‘technology-critical elements’, a set of chemical elements increasingly used in technological applications, in environmental matrices. Nowadays, inductively coupled plasma-mass spectrometry (ICP-MS) has become the technique of choice for measuring trace element concentrations. However, its application is often less straightforward than often assumed. The hints and drawbacks of ICP-MS application to the measurement of a set of less-studied technology-critical elements (Nb, Ta, Ga, In, Ge and Te) is discussed here and concise guidelines given.

  • 24.
    Cabri, Louis J.
    et al.
    Cabri Consulting Inc, Ottawa, Canada.
    Aiglsperger, Thomas
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    A review of hexaferrum based on new mineralogical data2018Ingår i: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 82, nr 3, s. 531-538Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Hexaferrum, defined as an hcp Fe mineral containing varying amounts of Ru, Os, or Ir(Mochalov et al. 1998) was re-examined in the light of new analyses of similar alloys from the Loma Peguera and Loma Larga chromitites, in the central part of Loma Caribe peridotite, Cordillera Central of the Dominican Republic, together with a review of the phase chemistry inthe Fe-Ni-Ir and Fe-Ru-Ir systems. We conclude that the hcp (Fe,Ir) mineral corresponds to theε-phase of Raub et al. (1964) and should be differentiated from hexaferrum [(Fe,Os) and(Fe,Ru)] because it is separated by one to two miscibility gaps and therefore is not a continuous solid solution with Fe.

  • 25.
    Rodushkin, Ilia
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik. ALS Laboratory Group, ALS Scandinavia AB, Luleå.
    Paulukat, Cora
    ALS Laboratory Group, ALS Scandinavia AB, Luleå.
    Pontér, Simon
    ALS Laboratory Group, ALS Scandinavia AB, Luleå.
    Engström, Emma
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik. ALS Laboratory Group, ALS Scandinavia AB, Luleå.
    Baxter, Douglas
    ALS Laboratory Group, ALS Scandinavia AB, Luleå.
    Sörlin, Dieke
    ALS Laboratory Group, ALS Scandinavia AB, Luleå.
    Pallavicini, Nicola
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik. ALS Laboratory Group, ALS Scandinavia AB, Luleå.
    Rodushkina, Katerina
    Department of Chemistry, Uppsala University, Uppsala.
    Application of double-focusing sector field ICP-MS for determination of ultratrace constituents in samples characterized by complex composition of the matrix2018Ingår i: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 622-623, s. 203-213Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The performance of double focusing, sector field mass spectrometry (ICP-SFMS) for determination of analytes, including technology critical elements (TCE), at ultra-trace levels in environmental and clinical matrices was critically evaluated. Different configurations of the ICP-SFMS introduction system as well as various sample preparations, pre-concentration and matrix separation methods were employed and compared. Factors affecting detection capabilities and accuracy of data produced (instrumental sensitivity, contamination risks, purity of reagents, spectral interferences, matrix effects, analyte recovery and losses) were discussed. Optimized matrix-specific methods were applied to a range of reference and control materials (riverine, brackish and seawaters; whole blood, serum and urine) as well as tap water and snow samples collected in the area of Luleå city, northern Sweden; brackish and seawater from the Laptev Sea; venous blood samples with a special emphasis on determination of Au, Ag, Ir, Os, Pd, Pt, Re, Rh, Ru, Sb and Te. Even though these low abundant elements are relatively under-documented, the results produced were compared with published data, where available.

  • 26.
    Hamberg, Roger
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Cementation of cyanidation tailings – effects on the release of As, Cu, Ni and Zn2018Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Knowledge about mineralogy and chemical composition in sulfidic tailings is essential to predict how tailings management may affect the future leachate quality. At a gold mine in the north of Sweden, gold was extracted from inclusions in arsenopyrite and pyrrhotite by the use of cyanide. Sulfides in the ore dissolved to a large extent during the cyanide leaching process causing sulfide-related elements such as As, Cu, Ni and Zn to be mobilized to a various extent. In a subsequent water treatment process, a significant proportion of As and Cu was captured in secondary formed Fe-precipitates. Large proportions of water-soluble Ni- and Zn-species in tailings suggested that this treatment was insufficient to reduce the mobility of Ni and Zn. Maintaining oxidized, neutral conditions is of major importance for the immobility of As, Cu, Ni and Zn during further management of the cyanidation tailings (CT).

    Part of the CT were planned to be managed in underground cavities by the use of a cemented paste backfill (CPB) -application. In CPB, a monolithic mass is formed as tailings are mixed with small proportions (4-7 weight %) of pozzolanic materials and backfilled into underground excavated areas. Using a CPB-application may decrease the sulphide oxidation rate, reducing exposure of mineral surfaces to oxygen and increasing water saturation levels within the material. In this study, CT was mixed with binders (1-3 wt. %) for the formation of a low-strength (0.2 Mpa) CT-CPB-mass. These mixtures were stored at moisturized conditions and subsequently subjected to oxidized and flooded conditions in a laboratory-based study. During short-term storing, high water saturation levels were preserved in the CT-CPB-mixtures, but, sulfide oxidation still progressed, and the release of Zn, Cu, and Ni was still lower compared to that in CT. The opposite was true for As, probably due to a desorption from Fe-precipitates. The desorbed As was subsequently incorporated into less acid-tolerant species (i.e. Ca-arsenates and As bonded to cementitious phases) in the CT-CPB:s, that readily dissolved and released more As compared to that in CT.

    A complete flooding of CPB-filled workings may take a long time to be reached. During this transition period, zones with low levels of water saturation forms in the CPB-monoliths, which could increase the sulphide oxidation rate, lower pH and dissolve the cementitious binders. In this study, strength decreased along with the water saturation levels in the CPB-mixtures, due to a more extensive pyrrhotite oxidation. A minimal proportion (1 wt. %) of binders did not suppress Cu and As leaching during flooding, but Ni and Zn-leaching were still lower than from CT. In the CT-CPB:s, proportions of As, Cu, Ni and Zn associated with cementitious phases increased in tandem with the fraction of binders. Using higher binder proportions in the CPB, as water saturation levels were lowered, substantially increased the Zn-release while there was an insignificant change in the As-release, and substantially lower Cu- and Ni-release. Pyrrhotite oxidation proceeded in the CT-CPB-mixtures independent of water saturation level. So, increasing binder proportion in a CPB does not necessary mean that trace metals are more stabilized, due to the formation of acid-intolerant fractions. Results from this study, pinpoints the importance of having knowledge about trace element distribution and mineral assemblage in tailings before management methods are chosen and implemented.

  • 27.
    Liu, Jian-li
    et al.
    School of Energy and Environment Engineering, University of Science and Technology Beijing.
    Yao, Jun
    School of Water Resource and Environment Engineering, China University of Geosciences, Beijing.
    Wang, Fei
    School of Energy and Environment Engineering, University of Science and Technology Beijing, Beijing.
    Ni, Wen
    School of Civil and Resource Engineering, University of Science and Technology Beijing.
    Liu, Xing-yu
    National Engineering Laboratory of Biohydrometallurgy, General Research. Institute for Nonferrous Metals .
    Sunahara, Geoffrey
    Department of Natural Resource Sciences, McGill University, Montreal, Quebec.
    Duran, Robert
    Equipe Environnement et Microbiologie, MELODY group, Université de Pau et des Pays de l’Adour, IPREM UMR CNRS.
    Jordan, Gyozo
    Department of Applied Chemistry, Szent István University.
    Hudson-Edwards, Karen A.
    Environment & Sustainability Institute and Camborne School of Mines, University of Exeter.
    Alakangas, Lena
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Solevic-Knudsen, Tatjana
    Institute of Chemistry, Technology and Metallurgy, University of Belgrade.
    Zhu, Xiao-zhe
    School of Energy and Environment Engineering, University of Science and Technology Beijing.
    Zhang, Yi-yue
    School of Energy and Environment Engineering, University of Science and Technology Beijing.
    Li, Zi-fu
    School of Energy and Environment Engineering, University of Science and Technology Beijing.
    China's most typical nonferrous organic-metal facilities own specific microbial communities2018Ingår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 8, nr 1, artikel-id 12570Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The diversity and function of microorganisms have yet to be explored at non-ferrous metal mining facilities (NMMFs), which are the world's largest and potentially most toxic sources of co-existing metal(loid)s and flotation reagents (FRs). The diversity and inferred functions of different bacterial communities inhabiting two types of sites (active and abandoned) in Guangxi province (China) were investigated for the first time. Here we show that the structure and diversity of bacteria correlated with the types of mine sites, metal(loid)s, and FRs concentrations; and best correlated with the combination of pH, Cu, Pb, and Mn. Combined microbial coenobium may play a pivotal role in NMMFs microbial life. Arenimonas, specific in active mine sites and an acidophilic bacterium, carries functions able to cope with the extreme conditions, whereas Latescibacteria specific in abandoned sites can degrade organics. Such a bacterial consortium provides new insights to develop cost-effective remediation strategies of co-contaminated sites that currently remain intractable for bioremediation.

  • 28.
    Karlsson, Teemu
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik. Industrial Environments and Recycling Unit, Geological Survey of Finland, Kuopio, Finland.
    Räisänen, Marja Liisa
    Industrial Environments and Recycling Unit, Geological Survey of Finland, Kuopio, Finland.
    Lehtonen, Marja
    Mineral Processing and Materials Research Unit, Geological Survey of Finland, Espoo, Finland.
    Alakangas, Lena
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Comparison of static and mineralogical ARD prediction methods in the Nordic environment2018Ingår i: Environmental Monitoring & Assessment, ISSN 0167-6369, E-ISSN 1573-2959, Vol. 190, nr 12, artikel-id 719Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Acid rock drainage (ARD) is a major problem related to the management of mining wastes, especially concerning deposits containing sulphide minerals. Commonly used tests for ARD prediction include acid–base accounting (ABA) tests and the net acid generation (NAG) test. Since drainage quality largely depends on the ratio and quality of acid-producing and neutralising minerals, mineralogical calculations could also be used for ARD prediction. In this study, several Finnish waste rock sites were investigated and the performance of different static ARD test methods was evaluated and compared. At the target mine sites, pyrrhotite was the main mineral contributing to acid production (AP). Silicate minerals were the main contributors to the neutralisation potential (NP) at 60% of the investigated mine sites. Since silicate minerals appear to have a significant role in ARD generation at Finnish mine waste sites, the behaviour of these minerals should be more thoroughly investigated, especially in relation to the acid produced by pyrrhotite oxidation. In general, the NP of silicate minerals appears to be underestimated by laboratory measurements. For example, in the NAG test, the slower-reacting NP-contributing minerals might require a longer time to react than is specified in the currently used method. The results suggest that ARD prediction based on SEM mineralogical calculations is at least as accurate as the commonly used static laboratory methods.

  • 29.
    Roebbert, Y.
    et al.
    Leibniz Universität Hannover, Institut für Mineralogie.
    Rabe, K.
    Leibniz Universität Hannover, Institut für Mineralogie.
    Lazarov, M.
    Leibniz Universität Hannover, Institut für Mineralogie.
    Schuth, S.
    Leibniz Universität Hannover, Institut für Mineralogie.
    Schippers, A.
    Bundesanstalt für Geowissenschaften und Rohstoffe.
    Dold, Bernhard
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Weyer, S.
    Leibniz Universität Hannover, Institut für Mineralogie.
    Fractionation of Fe and Cu isotopes in acid mine tailings: Modification and application of a sequential extraction method2018Ingår i: Chemical Geology, ISSN 0009-2541, E-ISSN 1872-6836, Vol. 493, s. 67-79Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Sulfidic mine tailings have a high potential for contamination of the environment by triggering acid mine drainage. Hence, it is crucial to understand metal mobilization processes and to develop monitoring tools. Metal isotope fingerprinting as a potential monitoring tool for metal sulfide oxidation processes was in the focus of this study by using stable isotope signatures of Cu and Fe. For Fe, a six-step sequential extraction method was applied, in order to separate potential Fe-bearing minerals (water-soluble, exchangeable fraction, Fe(III)(oxyhydr)oxides, Fe-oxides, sulfides and organic compounds and residual/silicates). For Cu, this method was modified into a four step extraction method (water-soluble, exchangeable fraction, oxalate fraction/bound to Fe-oxides and sulfides/residual). To verify accuracy and precision of the sequential extraction method for metal isotope analysis, isotope fractionation during the extraction procedure was investigated employing minerals for which the mineral composition and the isotopic composition was known. The developed procedure is suitable to separate target minerals with only a small loss in the elemental budget. No significant isotope fractionation was observed during the extraction procedure.

    Application of this method on two sites of porphyry copper mine tailings in the Atacama Desert in Chile (Chañaral bay) revealed several implications about the mobilization of Fe and Cu in an environmental setting. Iron contents and Fe isotope compositions are homogeneous with depth (0–61 cm; δ56Fe ~0.2–0.3‰) for the bulk and the Fe(hyr)oxide fraction and only the deepest samples at ~60 cm exhibited lower δ56Fe values (~0‰), which are likely related to the occurrence of an alluvium at this depth. The Fe silicate fraction shows higher δ56Fe values (0.6–0.9‰), most likely because of preferential leaching of the light Fe isotopes. This consequently indicates a more pronounced Fe isotope fractionation with depth, as is expected from longer weathering. The Fe sulfide fraction is isotopically lighter compared to the Fe(hydr)oxide fraction, because during sulfide oxidation the heavy Fe isotopes prefer the oxidized forms and oxidative precipitation results in an enriched Fe isotopic signature for Fe(hydr)oxides. The Cu isotope compositions of all bulk samples and individual fractions (except the Cu sulfides) of one site (Ch1) exhibited a decrease of the δ65Cu values from the depth towards the surface, i.e. in agreement with the capillary water rise in the arid climate. A correlation of δ65Cu with pH indicates preferential adsorption of 65Cu on Fe(oxy)hydroxides at site Ch1, which is evident by a change of δ65Cu from 0.5‰ to −0.7‰ in the water-soluble fraction. At another site (Ch12), where pH at depths was potentially not high enough for the formation of Fe-minerals that could adsorb Cu, only minor Cu isotope fractionation was observed in the water-soluble fraction. The Cu sulfide fraction at site Ch1 exhibits higher δ65Cu values with an increase from the bottom (0.42‰) to the surface (0.92‰), which might be related to preferential leaching of the light isotopes, e.g. by microorganisms.

  • 30.
    Hällström, Lina, P.B
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Geochemical Characterization of Historical W, Cu and F Skarn Tailings at Yxsjöberg, Sweden: With focus on scheelite weathering and tungsten (W) mobility2018Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    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.

  • 31.
    Hällström, Lina
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Alakangas, Lena
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Martinsson, Olof
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Geochemical characterization of W, Cu and F skarn tailings at Yxsjöberg, Sweden2018Ingår i: Journal of Geochemical Exploration, ISSN 0375-6742, E-ISSN 1879-1689, Vol. 194, s. 266-279Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Little attention has been paid to tailings from skarn ore deposits and their environmental impact, even though they can contain elevated concentrations of elements of potential concern together with sulfides and fluorite. Historical skarn tailings 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 environmental impact and the potential to re-mine the tailings. The tailings 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 >30 years. Four vertical cores throughout the tailings were taken and divided into 134 subsamples, which were analyzed for total concentrations 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) that pinpoints the quantitative distribution of elements between the minerals in the tailings was carried out. The average concentrations of Be, Bi, Cu, Sn, Zn, W, F and S in the tailings were 284, 495, 946, 559, 301, and 960 ppm, and 1.9 and 1.2 wt%, respectively. The tailings has reached a late stage development due to pyrrhotite oxidation resulting in low pH (<4) in the uppermost tailings, and formations of secondary minerals such as gypsum, hydrous ferric oxides (HFO) and orthogonal calcite. Secondary pyrite and magnetite, formed from monoclinic pyrrhotite was detected, and different weathering rates of secondary pyrite, hexagonal and monoclinic pyrrhotite was indicated, with secondary pyrite as the most stable and monoclinic pyrrhotite as the least. The rare and easily-weathered mineral danalite (Fe4Be3(SiO4)3S) was found in the drilled rock cores and by XRD in the tailings. However, the mineral could not be found by optical microscopy or SEM-EDS. This suggests that the mineral has been weathered to a great extent, which poses a high risk of releasing elements of potential concern to the groundwater since danalite contains approximately 40% of the total Be and Zn concentrations in the tailings. Fluorine was mainly found in fluorite, Cu in chalcopyrite, and Bi in bismuthinite; which all showed signs of weathering in acidic condition in the uppermost part, subsequent with decreased concentrations, followed by accumulation peaks deeper down in the tailings correlated with Al. Tungsten was mainly found in scheelite; most grains were unweathered, but a few grains had altered rims or HFO on the mineral surfaces. Tin was mainly found in ferrohornblende, hedenbergite and grossular. Beryllium, Cu, F, and Zn has high potential to be released to the surrounding environment from the Smaltjärnen Repository, while W, Bi and Sn are relatively stable in the tailings. Most of the scheelite is intact and re-mining could, therefore, be a suitable remediation method that would both reduce the environmental impact and simultaneously support the supply of critical raw materials in the EU.

  • 32.
    Reinhardt, Nils
    et al.
    Institute of Mineralogy, Technische Universität Bergakademie Freiberg, Germany;Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Universitat de Barcelona (UB), Spain; Institute of Applied Mineralogy and Economic Geology (IML), RWTH Aachen University, Germany.
    Proenza, Joaquín A.
    Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Universitat de Barcelona (UB), Spain.
    Villanova-de-Benavent, Cristina
    Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Universitat de Barcelona (UB), Spain;School of Environment and Technology (SET), University of Brighton, UK.
    Aiglsperger, Thomas
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik. Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Universitat de Barcelona (UB), Spain.
    Bover-Arnal, Telm
    Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Universitat de Barcelona (UB), Spain.
    Torró, Lisard
    Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Universitat de Barcelona (UB), Spain;Especialidad Ingeniería Geológica, Sección Ingeniería de Minas, Pontificia Universidad Católica del Perú, Peru.
    Salas, Ramon
    Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Universitat de Barcelona (UB), Spain.
    Dziggel, Annika
    Institute of Applied Mineralogy and Economic Geology (IML), RWTH Aachen University, Germany.
    Geochemistry and Mineralogy of Rare Earth Elements (REE) in Bauxitic Ores of the Catalan Coastal Range, NE Spain2018Ingår i: Minerals, ISSN 2075-163X, E-ISSN 2075-163X, Vol. 8, nr 12, artikel-id 562Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Karst bauxite deposits are currently investigated as a new resource for rare earth elements (REE) in order to avoid present and future supply shortfalls of these critical metals. The present work focuses on the geochemistry and mineralogy of the REE in karst bauxite deposits of the Catalan Coastal Range (CCR), NE-Spain. It is revealed that the studied bauxitic ores have a dominant breccia and local ooido-pisoidic and pelitomorphic texture. The bauxitic ores are mostly composed of kaolinite and hematite, as well as of lesser amounts of boehmite, diaspore, rutile and calcite. The mineralogy and major element composition indicate incomplete bauxitization of an argillaceous precursor material possibly derived from the erosion of the Mesozoic Ebro massif paleo-high. The studied bauxites are characterized by ∑REE (including Sc, Y) between 286 and 820 ppm (av. 483 ppm) and light REE to heavy REE (LREE/HREE) ratios up to 10.6. REE are mainly concentrated in phosphate minerals, identified as monazite-(Ce) and xenotime-(Y) of detrital origin and unidentified REE-phosphates of a possible authigenic origin. REE remobilization presumably took place under acidic conditions, whereas REE entrapment in the form of precipitation of authigenic rare earth minerals from percolating solutions was related to neutral to slightly alkaline conditions. During the bauxitization process no significant REE fractionation took place and the REE distribution pattern of the bauxitic ores was governed by the REE budget of the precursor material. Finally, adsorption as a main REE scavenging mechanism in the studied CCR bauxite deposits should not be considered, since the presented data did not reveal significant REE contents in Fe-and Mn-oxyhydroxides and clay minerals.

  • 33.
    Bauer, Susanne
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Conrad, Sarah
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Ingri, Johan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Geochemistry of tungsten and molybdenum during freshwater transport and estuarine mixing2018Ingår i: Applied Geochemistry, ISSN 0883-2927, E-ISSN 1872-9134, Vol. 93, s. 36-48Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The geochemistry of tungsten (W) in the environment is poorly studied. Tungsten usually occurs in low concentrations in natural waters and is not very mobile. For this study, we analyzed W together with molybdenum (Mo) in the dissolved and particulate fractions of two boreal estuaries during different seasons. Additionally, we sampled first-order streams that drain different landscape types and the receiving northern Baltic Sea. Furthermore, surface sediment from the estuaries was analyzed to obtain a comprehensive overview of the distribution of W and Mo in a boreal environment.

    Both elements showed different distribution patterns during different seasons. While they decreased in the dissolved fraction during spring discharge, in winter, their concentrations were elevated. Molybdenum exhibited non-conservative behavior along the salinity gradient in winter, which was probably caused by its release from underlying sediments. In the particulate fraction, we found opposite behaviors for Mo and W, with higher particulate W and lower particulate Mo during spring discharge.

    Molybdenum and W underwent fractionation from land to sea, indicating the different mobilities of these oxyanions. The Mo/W ratio in the dissolved fraction was mainly determined by the Mo concentration, as the W concentration varied only in a narrow range from first-order streams to the Bothnian Bay. In the particulate fraction, the Mo/W ratio appeared to be affected by scavenging processes and showed only small variations.

  • 34.
    Nigéus, Susanne
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Green liquor dregs-amended till to cover sulfidic mine waste2018Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The mining industry produces massive amounts of waste that without treatment and in contact with oxygen can result in acid rock drainage (ARD) and increased leaching of metals. In Sweden, the common way to manage the mine waste after closure is to apply a dry coverage on top of the waste deposition. The access to a suitable cover-material is however limited and can lead to extensive costs for the mining company. This creates a great driving force for alternative solutions, e.g. bentonite amendment to till. However, bentonite production is costly both economically and environmentally due to time- and resource- consuming production. Recycling of industrial residues as a cover material is another option. The recycling is beneficial for many parts, i.e. the industry producing the residue, the mining industry that will use the residue and the society in its strive for zero waste. An industrial residue that has potential to improve the sealing layer qualities of a local till is Green Liquor Dregs (GLD), a residue from pulp production in a paper mill. In this study 5 to 20 wt. % of GLD from two different paper mills, with varying total solid content (TSC) and particle size distributions (PSD), were mixed with three tills also with varying PSD and TSC. The objectives of the study were to investigate if GLD addition can improve a till so it can be used in a sealing layer, how the fines- and clay content in the tills affects the hydraulic conductivity (HC) and the water retention capacity (WRC) of the till-GLD mixtures, and how the initial water content will affect the HC in the different mixtures. The HC of the mixtures based most of the tills studied improved, but not enough to reach the required 10-8 m/s. Only the material based on a more clayey silty till had an HC below 10-8 m/s, even if it increased with the addition of GLD. The WRC, on the other hand, shows promising results, especially for 15 wt. % GLD addition. An increase in WRC is seen the more GLD is added. However, due to compaction difficulties more than 20 wt. % addition is not recommended. There is a difference in both HC and WRC between the mixtures based on the different tills, and a characterization of the till as a bulk material and its mixture with GLD is suggested before using it in mine remediation purposes. The HC of the till is affected by the content of fines and especially clay. The results from the WRC is more complicated and a mineralogical study on the GLD and the clay fraction of the tills is recommended. This study also shows that the initial water content of the materials rather than dry density has an impact on the HC of the mixtures. The initial water content determines the degree wet of optimum that in this and previous studies has shown to greatly affect the HC. A drier till and GLD leads to that more GLD should be added to the mixture when reaching for optimal HC. Even if the study did not result in low enough HC in most of the cases, the WRC shows promising results and is the most important parameter minimizing the oxygen diffusion to the mine waste. The greatest challenge when working with GLD is, however, its heterogeneity which makes it difficult to predict how it will behave in a sealing layer. Even though, the recycling of GLD in mine waste remediation should be strived for as it is beneficial for both the industry that provides the residue and the mining company. It is also a great profit for the environment as it minimizes the waste disposed and reduce use of natural resources.

  • 35.
    Schwalfenberg, Gerry
    et al.
    University of Alberta.
    Rodushkin, Ilia
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik. Scandinavia Division of A.L.S. Laboratory Group.
    Genuis, Stephen J.
    Department of Obstetrics and Gynecology, University of Alberta.
    Heavy metal contamination of prenatal vitamins2018Ingår i: Toxicology reports, ISSN 1972-6325, E-ISSN 2214-7500, Vol. 5, s. 390-395Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Prenatal vitamins are often consumed daily during gestation and postnatally for up to 18–24 months with the belief that supplementation achieves better outcomes. Detrimental effects of gestational exposure to adverse chemical agents are gathering increasing attention. This study was designed to assess toxic element contamination in prenatal supplements.

    Twenty-six commonly used prenatal vitamin brands including one prescription brand were collected from Canadian health-food outlets and pharmacies, and tested for toxic element contamination. Results were compared to established endpoints.

    All samples contained Lead with average amounts being (0.535 μgm), 20/51 samples exceeded established standards for lead toxicity (0.50 μgm/day), with one sample yielding 4. μgm/day. Three samples registered inorganic arsenic levels above acceptable limits. Cadmium levels did not exceed current standards. Toxic elements such as Aluminum, Nickel, Titanium and Thallium were detected in all samples.

    Cumulative intake of prenatal supplement over many months may constitute a significant source of toxic element exposure to the mother and offspring. With several samples exceeding known standards for gestational toxic element exposure, guidelines for routine monitoring and reporting are required. In keeping with recommendations from the International Federation of Obstetrics and Gynecology, industry regulation would be welcomed to protect expectant mothers and their vulnerable offspring.

  • 36.
    Ingri, Johan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Conrad, Sarah
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Lidman, Fredfrik
    Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå.
    Nordblad, Fredrik
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Engström, Emma
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik. ALS Laboratory Group, ALS Scandinavia AB.
    Rodushkin, Ilia
    ALS Laboratory Group, ALS Scandinavia AB.
    Porcelli, Don
    Department of Earth Sciences, University of Oxford.
    Iron isotope pathways in the boreal landscape: Role of the riparian zone2018Ingår i: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 239, s. 49-60Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Stable Fe isotope compositions have been measured in water samples of the subarctic Kalix River, a first-order stream, and soil water samples from a riparian soil profile adjacent to the first-order stream (Northern Sweden). In the first-order stream, dominated by forest, both the particulate (>0.22 µm) and dissolved (<0.22 µm) phase showed negative δ56Fe values (relative to IRMM-014) during base flow and meltwater discharge in May (−0.97 to −0.09‰). The Fe isotope composition in the water from the riparian soil profile varied between −0.20 and +0.91‰ with sharp gradients near the groundwater table. A linear correlation between the δ56Fe values and the TOC/Febulk ratio was measured during snowmelt in the unfiltered river waters (δ56Fe from −0.02 to +0.54‰), suggesting mixing of two Fe components. Two groups of Fe aggregates, with different Fe isotope compositions, are formed in the boreal landscape. We propose that carbon-rich aggregates, Fe(II)(III)-OC, have negative δ56Fe values and Fe-oxyhydroxides have positive δ56Fe values. A mixture of these two components can explain temporal variations of the Fe isotope composition in the Kalix River. This study suggests that stable Fe isotopes can be used as a tool to track and characterize suspended Fe-organic carbon aggregates during transport from the soil, via first-order streams and rivers, to coastal sediment. Furthermore, the differences in Fe isotope values in the Kalix River and the first-order stream during base flow conditions suggest that the primary Fe sources for river water change throughout the year. This model is combining the Fe isotope composition of first-order streams and rivers to weathering and transport processes in the riparian soil.

  • 37.
    Hällström, Lina
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Alakangas, Lena
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Martinsson, Olof
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Metal Release from Acidic and Near-Neutral pH-Conditions in Historical W, Cu and F Skarn Tailings at Yxsjöberg, Sweden2018Ingår i: 11th ICARD | IMWA | WISA MWD 2018 Conference: Risk to Opportunity / [ed] Wolkersdorfer, Ch.; Sartz, L.; Weber, A.; Burgess, J.; Tremblay, G., 2018, Vol. 1, s. 351-356Konferensbidrag (Refereegranskat)
    Abstract [en]

    Weathering products stored in the pore water and/or as easily soluble salts in historical skarn tailings containing Be, Bi, Cu, W, and Zn, were released in water soluble fraction in the upper-most acidic tailings, at the visual oxidation front (1.5m), and/or below 2.5m (pH>7). Thus, there is a risk that these metals can pollute receiving waters by neutral mine drainage. Re-mining the tailings could be a suitable remediation method that would both reduce the environmental impact and simultaneously support the supply of metals.

  • 38.
    Nilsson, Lino
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Widerlund, Anders
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Modelling tool for predicting and simulating nitrogen concentrations in cold-climate mining ponds2018Ingår i: Ecological Modelling, ISSN 0304-3800, E-ISSN 1872-7026, Vol. 380, s. 40-52Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A nitrogen model was developed with the aim to trace nitrogen cycling in a cold climate-mining pond at the Aitik copper mine in northern Sweden. The model contains 10 state variables and 19 nitrogen cycling reactions. The model also includes sediment and physical properties of the pond, such as evaporation, freezing and thawing. The model was written in Mathworks MATLAB and was calibrated and validated using environmental monitoring data for the clarification pond at the Aitik mine. The data used comprised monthly values of nitrogen speciation, phosphorous and water flow. The model accurately predicts ammonium (r2 = 0.84) and nitrate (r2 = 0.82) concentrations in a time series from February 2012–August 2014. The model did not accurately predict nitrate concentrations (r2 = 0.11), presumably due to high oxygen concentration in the pond water that prevented denitrification in the water column. The transport of organic material to the sediment was also limiting denitrification in the sediment. When allowing denitrification in the water column as well as increasing the rate of transport of organic material to the sediment the nitrate prediction capacity increased to a satisfactory level (r2 = 0.54). A sensitivity analysis for the system showed that the most sensitive reactions for the water column were oxic mineralisation as well as the nitrification rate.

  • 39.
    Malinovsky, Dmitry N.
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik. LGC Limited.
    Kashulin, Nikolay A.
    Russian Academy of Sciences, Institute of North Industrial Ecology Problems, Moscow, Russian Federation.
    Molybdenum isotope fractionation in plants measured by MC-ICPMS2018Ingår i: Analytical Methods, ISSN 1759-9660, E-ISSN 1759-9679, Vol. 10, nr 1, s. 131-137Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A new method was developed for precise and accurate Mo isotope ratio measurements in plant materials by multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS). It is based on the use of anion-exchange chromatography to isolate Mo from concomitant matrix elements in sample digests, a desolvating Apex-Q sample inlet system as a means of Mo signal enhancement and on-line normalisation to an admixed internal standard (Pd) to correct for instrumental mass bias. Mo isotope ratios were determined in sample solutions with Mo concentrations as low as 10 ng g-1. The developed method was successfully applied to the determination of natural variations in the isotopic composition of Mo in different anatomical parts of plants. We show for the first time that Mo isotope fractionation can occur during long-distance transport of Mo in plants. Our data also show that the magnitude of Mo isotope fractionation during translocation of Mo is different for different plant species. Mo isotope ratio data obtained by MC-ICPMS can therefore be used as a sensitive probe of processes controlling transport and distribution of molybdenum in plants. 

  • 40.
    Nigéus, Susanne
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Maurice, Christian
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik. Ramböll Sverige AB, Luleå.
    Monitoring a field application of a Green Liquor Dregs-till mixture in a sealing layer on top of sulfidic mine waste2018Ingår i: 11th ICARD | IMWA | WISA MWD 2018 Conference: Risk to Opportunity, 2018, s. 57-63Konferensbidrag (Refereegranskat)
    Abstract [en]

    Sul dic mine waste le unattended and in contact with oxygen oxidize and have potential to produce acid rock drainage (ARD). A typical method in Sweden to stop sul de oxidation is to apply a dry cover on top of the mine waste. Using the non-hazardous industrial residue Green Liquor Dregs (GLD) in the cover is useful for the mining industry and the industry providing the residue and a large bene t for the environment. In this study, the e ectiveness of a mixture of till and 10 wt. % of GLD in a dry cover was studied by monitoring temperature, oxygen- and moisture content. e conclusion is that the sealing layer in una ected by frost, the oxygen concentrations are decreasing with time, but not in depth and the sealing layer with GLD-till mixture seem to be nearly saturated.

  • 41.
    Nilsson, Lino
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Nitrogen-cycling tracing methods: Case studies at cold-climate mine sites in northern Sweden2018Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    High nitrogen effluents from mine sites is an environmental issue which has received relatively little attention historically. In recent years a number of studies have showed the environmental effects of high nitrogen discharge to natural water bodies, which include local eutrophication, high risk of acute reducing conditions and changed species composition in the receiving waters. Apart from the direct environmental effects of high nitrogen discharge some forms of nitrogen can be directly toxic- ammonia and nitric gas for instance, and some can be indirectly toxic, for instance nitrate which causes methemoglobinemia in infants if ingested.

    This thesis shows how the developed nitrogen tracing methods can be applied in complex water transport systems such as in a mining environment. Two main study sites were used in this thesis, the LKAB iron mine at Kiruna and the Aitik copper mine at Gallivare operated by Boliden Mineral AB. The nitrogen tracing methods used in this study are stable isotope analysis, combined nitrogen and oxygen isotope analysis, source partitioning using linear combination of sources, numerical analysis using kinetic nitrogen reaction rates, numerical model verification using stable nitrogen isotopes, and Bayesian statistical models to estimate nitrogen concentrations. The study also demonstrates an experimental method of reducing nitrogen concentrations in the mining pond at the LKAB Kiruna site. The nitrogen reducing method was tested in a small scale mesocosm experiment at the Kiruna site in northern Sweden, where a nitrogen reduction rate of around 0.25 - 0.5% total nitrate per day could be achieved.

    The nitrogen treatment method consists of fertilising the pond system with small amounts of bioavailable phosphorus. Phosphorus is generally the limiting factor for primary production and in the studied mining systems which have high nitrogen concentrations the phosphorus is assimilated into organic matter almost immediately after fertilisation. The phosphorus is assimilated into phytoplankton (algae) which then settles and is used as a carbon source during anaerobic decomposition (denitrification). The denitrification reaction reduces nitrate into nitrogen gas. This would reduce the nitrogen release from mine sites significantly, since nitrate is the dominant form of nitrogen at the two studied mine sites.

    Concluding the thesis is a 2.5D model which couples a numerical kinetic nitrogen model with a hydrodynamic model. The hydrodynamic model was the Shallow Water Equations (SWE) model that incorporates wind turbulence, inlets, and outlets as source terms for the water velocities. The two models are coupled via velocity, where the nitrogen model couples via chemical mixing and fluxes are calculated from the water velocities in each model cell.

    The results of this thesis suggests that nitrogen release from the the Kiruna clarification pond could be reduced significantly via the use of phosphorus fertilisation. This is due to an increased denitrification rate in the pond, and the fact that much of the discharge water from the pond system is recirculated back into the mineral processing plants. The recirculation essentially means that the nitrate in the mine water will have quite a long retention time before being passed out the receiving waters.

    Although the presented nitrate reduction approach showed promising reduction rates, the potential risk of eutrophication in the receiving waters is high, as the discharge water will contain high levels of nitrogen and potentially also phosphorus. The transport pathways and possible natural attenuation of phosphorus must be thoroughly investigated before the presented nitrate reduction method can be implemented at full scale in mine ponds.

  • 42.
    Navidad, Marina
    et al.
    Área de Petrología y Geoquímica, Facultad de Ciencias Geológicas, Universidad Complutense de Madrid.
    Castiñeiras, Pedro
    Área de Petrología y Geoquímica, Facultad de Ciencias Geológicas, Universidad Complutense de Madrid.
    Casas, Josep M.
    Department de Dinàmica de la Terra i de l'Oceà-Institut de Recerca Geomodels, Universitat de Barcelona.
    Liesa, Montserrat
    Department de Mineralogia, Petrologia i Geologia Aplicada, Universitat de Barcelona.
    Belousova, Elena
    Department of Earth and Planetary Sciences, ARC Centre of Excellence for Core to Crust Fluid Systems (CCFS), GEMOC Macquarie University, Sydney.
    Proenza, Joaquín A.
    Department de Mineralogia, Petrologia i Geologia Aplicada, Universitat de Barcelona.
    Aiglsperger, Thomas
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Ordovician magmatism in the Eastern Pyrenees: Implications for the geodynamic evolution of northern Gondwana2018Ingår i: Lithos, ISSN 0024-4937, E-ISSN 1872-6143, Vol. 314-315, s. 479-496Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    New data on the geochemistry and geochronology of different felsic gneisses and metabasites from the Variscan massifs of Eastern Pyrenees have allowed us to shed some light on the Ordovician magmatic evolution in northern Gondwana during the opening of the Rheic Ocean. According to these data, the Ordovician magmatism represents a continuous event of anatectic melting, with limited mantle influence, that lasted 20 m.y., from Early to Late Ordovician. In the Canigó massif, peraluminous monzogranitic and granodioritic metaigneous rocks intruded a late Ediacaran-early Cambrian sequence at 464.3 ± 1.6 Ma and 461.6 ± 1.5 Ma, respectively, and leucogranitic gneisses intruded at 457.4 ± 1.6 Ma. Whole-rock geochemistry of the felsic rocks (plutonic and subvolcanic) points to a volcanic arc setting. However, the geological context and the geochemistry of the coeval metabasites are incompatible with this tectonic setting and point out to the inception of an extensional margin. Sm-Nd isotopic data suggest that the felsic rocks are derived from the anatexis of juvenile igneous rocks (probably Cadomian), mixed with older crustal components present in a late Neoproterozoic crust. We interpret that the Ordovician magmas inherited the geochemical signature of the rocks formed at the former Cadomian convergent margin. The variation of the εNd values from −2 to −4 in the Lower Ordovician rocks, to −5 in the Upper Ordovician rocks suggests a greater implication of the older component in a within-plate geodynamic context, coeval with the evolution of an extensional marginal basin linked to the opening of the Rheic Ocean. A similar isotopic evolution, more depleted first and with a greater implication of the crust in the younger sample, is shown by the studied metabasites.

  • 43.
    Rivera, Javier
    et al.
    Department of Geology and Andean Geothermal Center of Excellence (CEGA), FCFM, Universidad de Chile, Santiago, Chile.
    Reich, Martin
    Department of Geology and Andean Geothermal Center of Excellence (CEGA), FCFM, Universidad de Chile, Santiago, Chile.
    Schoenberg, Ronny
    Department of Geosciences, University of Tübingen, Tübingen, Germany.
    González Jiménez, José María
    Departmento de Mineralogía y Petrología, Facultad de Ciencias, Universidad de Granada, Spain.
    Barra, Fernando
    Department of Geology and Andean Geothermal Center of Excellence (CEGA), FCFM, Universidad de Chile, Santiago, Chile.
    Aiglsperger, Thomas
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Proenza, Joaquín
    Departament de Mineralogia, Petrologia i Geologia Aplicada, Universitat de Barcelona (UB), Barcelona, Spain.
    Carretier, Sebastien
    GET, Université de Toulouse, CNRS, IRD, Toulouse, France.
    Platinum-group element and gold enrichment in soils monitored by chromium stable isotopes during weathering of ultramafic rocks2018Ingår i: Chemical Geology, ISSN 0009-2541, E-ISSN 1872-6836, Vol. 499, s. 84-99Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Weathering of ultramafic rocks can lead to the formation of soil profiles with high contents of Fe, Ni, Co, platinum-group elements (PGE) and gold. Traditionally, these metal-rich soils are known as “laterites” and are formed under tropical climates and stable tectonic conditions. However, little is known about their possible development in cold/humid regions, and the factors governing PGE and gold mobility and enrichment under these weathering conditions are poorly constrained. In this study, five soil profiles developed on serpentinized, chromite-bearing ultramafic rocks at La Cabaña, located in the Coastal Range of south-central Chile (38° S) were studied by combining major and trace element geochemistry with chromium stable isotope data. The results show that the soils developed at La Cabaña have higher PGE and Au contents than the parent serpentinite rock, with ∑PGE and Au reaching up to 160 ppb and 29 ppb in a limonitic soil horizon and clay saprolite, respectively. Most soil samples have slightly negative δ53/52CrSRM979 values, within a range of −0.089 ± 0.012‰ to −0.320 ± 0.013‰ (average of −0.178‰), and are in agreement with previous data reported for modern soils. A noteworthy relation between δ53/52Cr data and PGE + Au contents is observed in the studied soil horizons, where isotopically lighter values of δ53/52Cr match the higher contents of PGE and gold. These results show that pedogenetic processes operating at the cold and humid La Cabaña area are capable of increasing the total PGE and Au contents of certain soil horizons. Such processes are complex and multivariate but are primarily modulated by chromite dissolution and the formation of secondary phases such as clay minerals and oxy-hydroxide phases in the soil. These findings provide evidence that important weathering and PGE + Au supergene accumulation are not only restricted to tropical latitudes, and that the chromium isotope system is a useful proxy to track surface redox process and noble metal enrichment during pedogenesis.

  • 44.
    Pallavicini, Nicola
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik. ALS Laboratory Group, ALS Scandinavia AB, Luleå, Sweden.
    Engström, Emma
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik. ALS Laboratory Group, ALS Scandinavia AB, Luleå, Sweden.
    Baxter, Douglas C.
    ALS Laboratory Group, ALS Scandinavia AB, Luleå, Sweden.
    Öhlander, Björn
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Ingri, Johan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Hawley, Scott
    Department of Earth Sciences, Durham University, Durham, UK.
    Hirst, Catherine
    Department of Geosciences, Natural History Museum, Stockholm, Sweden.
    Rodushkina, Katerina
    Department of Chemistry, Uppsala University, Uppsala, Sweden.
    Rodushkin, Ilya
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik. ALS Laboratory Group, ALS Scandinavia AB, Luleå, Sweden.
    Ranges of B, Cd, Cr, Cu, Fe, Pb, Sr, Tl, and Zn Concentrations and Isotope Ratios in Environmental Matrices from an Urban Area2018Ingår i: Journal of Spectroscopy, ISSN 2314-4920, E-ISSN 2314-4939, s. 1-17, artikel-id 7408767Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Isotopic information may provide powerful insight into the elemental cycling processes which occur in natural compartments. Further implementation of isotopic techniques in natural sciences requires a better understanding of the range of elemental and isotopic compositional variability in environmental matrices. This study assesses the local-scale concentration and isotopic composition variability of nine elements: boron (B), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), lead (Pb), strontium (Sr), thallium (Tl), and zinc (Zn) in lysimetric waters, mushrooms, litter, needles, leaves, and lichens. Sequential extractions were also performed on soil samples from 6 depth profiles providing more detailed information on the variability of elemental concentrations and isotope ratios between the elemental pools present in soil. For most of the sample types studied the range of isotopic variability between samples spans almost the entire ranges reported in the literature for natural samples. These results represent a starting point for discussing the role of natural variability in isotopic studies (for example, as a limiting factor in the use of isotopic mixing models) and a baseline for future in-depth studies examining the controls on isotope fraction in natural systems

  • 45.
    Salifu, Musah
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Aiglsperger, Thomas
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Hällström, Lina
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Martinsson, Olof
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Billström, Kjell
    Department of Geological Sciences, Swedish Museum of Natural History, Frescativagen 40, Box 50007, 104 05, Stockholm, Sweden.
    Ingri, Johan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Dold, Bernhard
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Alakangas, Lena
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Strontium (87Sr/86Sr) isotopes: A tracer for geochemical processes in mineralogically-complex mine wastes2018Ingår i: Applied Geochemistry, ISSN 0883-2927, E-ISSN 1872-9134, Vol. 99, s. 42-54Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Interpretation of geochemical data based primarily on elemental concentrations often lead to ambiguous results due to multiple potential sources including mineral weathering, atmospheric input, biological cycling, mineral precipitation and exchange processes. The 87Sr/86Sr ratio is however not fractionated by these processes. In this study, Sr isotope (87Sr/86Sr) ratios have been coupled with chemical data of Sr and Rb-bearing minerals, tailings and leachates (water-soluble) to gain insight into the geochemical processes occurring within the Yxsjöberg Cu-W mine tailings, Sweden. The tailings have been exposed to oxidizing conditions resulting in three geochemical zones namely (i) oxidized, (ii) transition and (iii) unoxidized zones. Leachates from the oxidized zone are acidic (pH = 3.6–4.5) and contain elevated concentrations of metals (e.g. Fe, Cu and Zn) and SO4. The low pH has also led to subsequent weathering of most silicates, releasing Al, Ca, Mg and Na into solution. The 87Sr/86Sr ratio in the tailings ranges from 0.84787 to 1.26640 in the oxidized zone, 0.92660–1.06788 in the transition zone, whilst the unoxidized zone has values between 0.76452 and 1.05169. For the leachates, the 87Sr/86Sr ratio ranges from 2.44479 to 5.87552 in the oxidized zone, 1.37404–1.68844 in the transition zone and 1.03697–2.16340 in the unoxidized zone. Mixing (between mineral weathering and atmospheric sources) was identified as the major process regulating the Sr composition of the tailings and leachates. The highly radiogenic signatures of the leachates in the oxidized zone suggests weathering of biotite, K-feldspar and muscovite. Despite the very radiogenic signatures in the oxidized zone, increments in Ca/K ratios, Be, Ce, Tl, Al, Fe and SO4 concentrations in the water-soluble phase were recorded in its lower parts which suggests the dissolution of amphibole, pyroxene, plagioclase, fluorite, gypsum, Al and Fe –(oxy) hydroxides as well as cation exchange by clay minerals. Presence of clay minerals has led to the partial retainment of radiogenic 87Sr/86Sr resulting in increased 87Sr/86Sr in the solid tailings material at these depths. The 87Sr/86Sr ratios of the water-soluble phase in the transition zone is similar to that of helvine and could indicate its dissolution. In the upper part of the oxidized zone, the 87Sr/86Sr ratios and trends of Be, Ca, SO4, Tl and Zn in the water-soluble phase suggest the dissolution of gypsum which precipitated from a leachate with the isotopic signature of helvine. In the lower part of the unoxidized zone, elevated concentrations of W were recorded suggesting scheelite weathering. But the 87Sr/86Sr ratios are higher than that expected from dissolution of scheelite and indicates additional processes. Possible sources include biotite weathering and groundwater. This study reveals that when interpreting geochemical processes in mine waste environments, 87Sr/86Sr should be considered in addition to chemical constituents, as this isotopic tracer offers better insights into discriminating between different solute sources.

  • 46.
    Nyström, Elsa
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Suitability of industrial residues for preventing acid rock drainage generation from waste rock2018Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]