Change search
Refine search result
12345 1 - 50 of 237
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the 'Create feeds' function.
  • 1.
    Alakangas, Lena
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Bark, Glenn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ericsson, Magnus
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Social Sciences.
    Martinsson, Olof
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Söderholm, Patrik
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Social Sciences.
    Wanhainen, Christina
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Weihed, Pär
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Norrbottens malm- och mineralresurs och dess potentiella betydelse för innovation, samhälle och miljö2014Report (Other academic)
    Abstract [sv]

    Gruvindustrins betydelse för samhällsutveckling och infrastruktur i Sverige och inte minst i Norrbottens län är mycket stor. De geologiska förutsättningarna att hitta nya brytvärda förekomster i Norrbotten är goda. Länet är tillsammans med Västerbotten en av Europas viktigaste regioner för utvinning av metaller. Det syns också i den nyligen framtagna regionala mineralstrategin för Norrbotten och Västerbotten. Visionen för den regionala mineralstrategin: ”Genom långsiktigt hållbart nyttjande av Norrbottens och Västerbottens läns mineralresurser har ytterligare tillväxt skapats i regionen och hela Sverige. Vi har utvecklat och stärkt vår ställning som ledande gruv- och mineralnation.”Eftersom framtidspotentialen för gruvnäringen är mycket god men okunnigheten hos både allmänhet och beslutsfattare om näringens betydelse för innovation och samhällsutveckling är stor, kopplat med en utbredd oro för miljöpåverkan, måste dessa viktiga framtidsfrågor belysas. Med finansiering från Länsstyrelsen i Norrbotten bedrevs därför under första hälften av 2014 en förstudie som syftade till att sammanfatta kunskapsläget om framtidens gruvindustri i Norrbotten. Resultaten av förstudien redovisas i den här rapporten. En viktig slutsats är att det under nästa strukturfondsperiod (med start 2015) behövs ett framtidsinriktat forskningsprogram för att belysa de möjligheter som finns. Denna förstudie utgör grund för en kommande ansökan till strukturfonderna. Kompetensen som finns vid Luleå tekniska universitet, Sveriges centrum för gruvrelaterad forskning och utbildning, bör användas för att studera troliga framtidsmöjligheter och hur de ska kunna användas för att få en så positiv utveckling som möjligt för länet. Projektet bör innehålla följande tre huvudinriktningar, som naturligtvis hör ihop:Vilka malm- och mineralresurser finns det potential för i Norrbotten, och vilka kommer sannolikt att exploateras i framtiden?Vad kommer den exploateringen att ha för betydelse för innovation och samhällsutveckling?Vad kommer den exploateringen att få för miljöeffekter och hur ska man göra för att minska miljöbelastningen?En annan slutsats är att nedlagda gruvområden inte måste ses som förstörd natur. Betydande mervärden som gruvturism skulle kunna skapas om vilja, kreativitet och beslutsamhet finns. Detta är ett givet utvecklingsområde där småföretag och entreprenörer kan göra stor insats om de politiska och myndighetsmässiga förutsättningarna finns. Dessa aspekter skulle också kunna belysas i det föreslagna forskningsprogrammet eller i ett eget projekt.

  • 2.
    Alakangas, Lena
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Lundberg, Angela
    Öhlander, Björn
    Changes of groundwater quality in sulphide-bearing mine-tailings as a result of remediation at Kristineberg, northern Sweden2007In: Mining and the Environment International Conference: proceedings, Centre for Environmental Monitoring, Laurentian University , 2007Conference paper (Refereed)
    Abstract [en]

    At the Kristineberg mine in northern Sweden, sulphide-rich tailings left open for 50 years were remediated in 1996 by applying double dry cover on one part of an impoundment, and raised groundwater level combined with simple till cover on the other part. Groundwater pipes installed in the impoundment were sampled from 1998 during a period of 6 years. The results showed that the groundwater quality varied considerably in the impoundment, even under the same type of cover. Secondarily retained Fe, S, Mg, Mn and Z were remobilised when the groundwater was raised. In the part with raised groundwater level, the average concentration of Fe ranged from 2700 to 9000mg/l in 1998, and the range for S was 2200 to 7000mg/l. During 2003 the average concentrations had decreased and ranged between 150 and 900 mg/l for Fe and between 130 and 900 mg/l for S. The improvement of the water quality was caused by inflow of less contaminated groundwater and decreasing sulphide oxidation rate. The redox potential generally decreased and pH increased. The concentrations of Cd, Cu and Pb in groundwater decreased rather rapidly all over the impoundment after remediation. In areas with relatively high pH and low redox potential, Al, Cd, Co, Cr, Cu, Fe, Ni, Pb and Zn were almost depleted.

  • 3.
    Alakangas, Lena
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Lundberg, Angela
    Öhlander, Björn
    Pilot scale studies of different dry covers on sulphide-rich tailings in northern Sweden, oxygen diffusion2005In: Securing the future: international conference on mining and the environment, metals and energy recovery : proceedings, Stockholm: SweMin , 2005, p. 9-18Conference paper (Other academic)
  • 4. Alakangas, Lena
    et al.
    Lundberg, Angela
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Pilot-scale studies of different covers on unoxidised sulphide-rich tailings, northern Sweden: oxygen diffusion2010In: Mine Water and the Environment: proceedings of the 10th IMWA Congress 2008 : 2-5 June, 2008 - Karlovy Vary, Czech Republic / [ed] Nadia Rapantova; Zbyněk Hrkal, Ostrava: VSB - Technical University Ostrava, Faculty of Mining and Geology, Institute of Environmental Engineering , 2010, p. 347-350Conference paper (Refereed)
    Abstract [en]

    The efficiency of five cover systems to decrease oxygen intrusion into sulphide-rich tailings was studied in pilot-scale test cells (5x5x3 m(3)). The covers consisted of clayey till, sewage sludge, fine-grained apatite concentrate or Trisoplast (a mixture of a polymer, bentonite and tailings sand) as sealing layers and unspecified till as protective cover. In one reference cell, tailings were uncovered. Oxygen concentrations below the entire covers were highest below the Trisoplast and apatite layers, and lowest below the sewage sludge layer. Effective diffusion coefficients (D-eff) and oxygen fluxes were estimated in the covers with non-oxygen-consuming sealing layers (clayey till and apatite). For the protective covers the Deff ranged between E-09 and E-07 m(2)/s, and for the sealing layers between E-10 and E-09 m(2)/s, and for the entire covers between E-10 and E-08 m(2)/s. Seasonal variations in D-eff were larger within the covers than between the different cover systems. Oxygen fluxes through the entire covers with clayey till and apatite ranged between 0.2 and 4 mole m(2)/year, which was a reduction of more than 99% compared to uncovered dry tailings.

  • 5.
    Alakangas, Lena
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Formation and composition of cemented layers in low-sulphide mine tailings, Laver, northern Sweden2006In: Environmental Geology, ISSN 0943-0105, E-ISSN 1432-0495, Vol. 50, no 6, p. 809-819Article in journal (Refereed)
    Abstract [en]

    Cemented layers (hardpans) are common in carbonate or sulphide-rich mine tailings and where pyrrhotite is the predominating Fe-sulphide. Laver, northern Sweden, is an abandoned Cu-mine where the tailings have low pyrrhotite content, almost no pyrite and no carbonates. Two cemented layers at different locations in the Laver tailings impoundment were investigated, with the aim to determine their effects on metal mobility. The cementing agents were mainly jarosite and Fe-oxyhydroxides in the layer formed where the tailings have a barren surface, whereas only Fe-oxyhydroxides were identified below grass-covered tailings surface. Arsenic was enriched in both layers which also exhibit high concentrations of Mo, V, Hg and Pb compared to unoxidised tailings. Sequential extraction indicates that these metals and As were mainly retained with crystalline Fe-oxides, and therefore potentially will be remobilised if the oxic conditions become more reducing, for instance as a result of remediation of the tailings impoundment.

  • 6.
    Alakangas, Lena
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Pilot-scale studies of different covers on unoxidised sulphide-rich tailings in northern Sweden: the geochemistry of leachate waters2006In: Mine Water and the Environment, ISSN 1025-9112, E-ISSN 1616-1068, Vol. 25, no 3, p. 171-183Article in journal (Refereed)
    Abstract [en]

    Leachate water quality from covered and uncovered unoxidised sulphide-rich tailings in six pilot-scale (5x5x3 m3) test cells was monitored during 2004 and 2005. The covers consisted of a layer of clayey till, sewage sludge, apatite or Trisoplast (a commercial mixture of tailings, bentonite, and a polymer). All layers were protected by an unspecified till except in one reference cell, where the tailings were left open. All leachate waters showed near-neutral pH as a result of neutralization by calcite in the tailings and by Ca(OH)2 added prior to deposition. Average dissolved sulphur concentrations in the leachates were ≈ 600 mg L-1, except in the cell with sewage sludge (300 mg L-1). The source of sulphur was mainly pyrite oxidation, but residual sulphur probably remained from the enrichment process. The near-neutral pH favoured precipitation of metal-(oxy)hydroxides with subsequent removal of trace elements such as Cd, Cu and Pb (< 15 μg L-1) from the solutions. High concentrations of Co, Mn, Ni, and Zn were found in leachates from the apatite, Trisoplast, and uncovered tailings cells. High As concentrations were found in the leachates in the sewage sludge and clayey till cells. The lowest metal concentrations, redox potential, and highest pH were found in the sewage sludge cell. Decreased elemental metal concentrations during 2004 suggest improved performance over time.

  • 7.
    Alakangas, Lena
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    The effect of vegetation on mine tailings2003In: Program with Abstracts : Joint Annual Meeting, Geological Association of Canada; Mineralogical Association of Canada , 2003, Vol. 28Conference paper (Other academic)
    Abstract [en]

    One of the major aims with passive remediation of sulfide-bearing mine tailings is to minimize or exclude oxygen diffusion through the tailings and decrease the oxidation of sulfides. A vegetation cover could potentially decrease the oxygen flux by oxygen consumption during decay of organic matter. The abandoned Cu mine at Laver in northern Sweden has not been remediated except for establishment of vegetation, and this offers the opportunity to investigate the effect of a vegetation cover on tailings.Whole-year sampling of surface drainage water from the tailings impoundment was performed during 1993 and 2001. The release of metals was only 5-10 % of the estimated weathering rate in the tailings during 1993 because of secondary retainment within the tailings. Results from 2001 show decreasing concentrations of several elements and increasing pH, indicating decreasing oxidation rate.Pore-gas measurement in two vertical profiles shows that vegetation on the tailings has no effect as a barrier for oxygen diffusion in comparison with barren parts.Cemented layers, which have formed at various depths in the tailings, have decreased the flux of oxygen to deeper parts; this could be an explanation of the decreased oxidation rate. The different cemented layers in the tailings differ in chemical composition and physical characteristics. There are two major types, both of which both contain iron oxides and carbon. The origin of the carbon is possibly the vegetation cover. None of the cemented layers acts as a trap for heavy metals, but As is enriched.The effect of vegetation as a oxygen barrier is negligible, but vegetation could act as a source for organic matter that could increase aggregation of iron oxides and clay minerals, thereby enhancing the formation of cemented layers or increasing metal-organic complexes which decrease the mobility of metals.

  • 8.
    Alakangas, Lena
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Lundberg, Angela
    Changes of sulphide oxidation rates over time in mine tailings, Laver, Northern Sweden2009In: 8th International Conference on Acid Rock Drainage (ICARD) and Securing the Future: Mining, Metals & the Environment in a Sustainable Society 2009: Skelleftea, Sweden, 22 - 26 June 2009, Red Hook, NY: Curran Associates, Inc., 2009Conference paper (Refereed)
  • 9.
    Alakangas, Lena
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Lundberg, Angela
    Estimation of temporal changes in oxidation rates of sulphides in copper mine tailings at Laver, Northern Sweden2010In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 408, no 6, p. 1386-1302Article in journal (Refereed)
    Abstract [en]

    Tailings containing pyrrhotite were deposited in an impoundment at a copper mine at Laver, Northern Sweden, which operated between 1936 and 1946. Since then the oxidation of sulphides has acidified recipient water courses and contaminated them with metals. Measurements from surface water sampled in 1993, 2001 and 2004-05 from a brook into which the tailing impoundment drains indicate that the amounts of sulphide-associated elements such as Cu, S and Zn released into the brook have decreased over time, while pH has increased. The mass transport of S in the brook during 1993 and 2001 corresponded well with the amount of S estimated to be released from the tailings by oxidation. Secondary precipitates such as covellite and gypsum, which can trap sulphur, were shown in earlier studies to be present in only low amounts. The annual release of elements from the tailings was estimated from the volume of tailings assumed to oxidise each year, which depends on movement of the oxidation front with time. The results indicate that the oxidation rate in the tailings has decreased over time, which may be due to the increased distance over which oxygen needs to diffuse to reach unoxidised sulphide grains, or their cores, in the tailings.

  • 10.
    Andersson, Per S.
    et al.
    Swedish Museum of Natural History.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Land, Magnus
    Widerlund, Anders
    Dahlqvist, Ralf
    Swedish Museum of Natural History.
    Gustafsson, Örjan
    Stockholm University.
    Weathering, transport, and sedimentation of rare earth elements and Nd-isotopes in a boreal river basin: brackish bay area2000In: Vol. 5, no 2, p. 146-Article in journal (Other academic)
  • 11.
    Axelsson, Mikael
    et al.
    Luleå tekniska universitet.
    Rodushkin, Ilia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Baxter, Douglas
    Ingri, Johan
    Öhlander, Björn
    High spatial resolution analysis of ferromanganese concretions by LA-ICP-MS2002In: Geochemical Transactions, ISSN 1467-4866, E-ISSN 1467-4866, Vol. 3, no 5, p. 40-47Article in journal (Refereed)
    Abstract [en]

    A procedure was developed for the determination of element distributions in cross-sections of ferromanganese concretions using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The effects of carrier flow rates, rf forward power, ablation energy, ablation spot size, repetition rate and number of shots per point on analyte intensity were studied. It is shown that different carrier gas flow rates are required in order to obtain maximum sensitivities for different groups of elements, thus complicating the optimisation of ICP parameters. On the contrary, LA parameters have very similar effects on almost all elements studied, thus providing a common optimum parameter set for the entire mass range. However, for selected LA parameters, the use of compromise conditions was necessary in order to compensate for relatively slow data acquisition by ICP-MS and maintain high spatial resolution without sacrificing the multielemental capabilities of the technique. Possible variations in ablation efficiency were corrected for mathematically using the sum of Fe and Mn intensities. Quantification by external calibration against matrix-matched standards was successfully used for more than 50 elements. These standards, in the form of pressed pellets (no binder), were prepared in-house using

  • 12.
    Axelsson, Mikael
    et al.
    Luleå tekniska universitet.
    Rodushkin, Ilya
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Multielemental analysis of Mn-Fe nodules by ICP-MS: optimisation of analytical method2002In: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 127, no 1, p. 76-82Article in journal (Refereed)
    Abstract [en]

    Two acid digestion procedures (microwave-assisted and room temperature) were developed for the quantitative analysis of ferromanganese nodules by inductively coupled plasma double focusing sector field mass spectrometry (ICP-SFMS). Different compositions of the acid mixture, dilution factors and corrections for spectral interferences were tested. A combination of nitric, hydrochloric and hydrofluoric acids is necessary for complete sample digestion, with lowest acid to sample ratios (v/m) of 15 and 1.5. respectively, for the last two acids. Sample dilution factors higher than 2 X 104 should be used in order to decrease matrix effects and provide robust long-term instrumental operation. In spite of high dilution. method detection limits in the sub-mug g(-1) range were obtained for 54 out of 71 elements tested. due to the high detection capability of ICP-SFMS, as well as the special care taken to ensure the purity of reagents, to clean the instrument sample introduction system and to minimise sample handling. Owing to the presence of unresolved (at the resolution available) spectral interferences, accurate determination of Au, Hg, Os, Pd, Re and Rh is impossible without matrix separation. The accuracy of the entire analytical method was tested by the analysis of two nodule reference materials. The results generated agreed to within +/-2% for about 10, within +/-10% for more than 40 and within +/-20% for about 50 of 53 elements for which certified, recommended or literature values are available. A precision better than 3%, expressed as the between-digestion relative standard deviation (n=4). was obtained for the majority of elements, except in cases limited by low analyte concentrations

  • 13. Billström, Kjell
    et al.
    Åberg, G.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Isotopic and geochemical data of the Pingstaberg Mo-bearing granite in Bergslagen, south central Sweden1988In: Geologie & Mijnbouw, ISSN 0016-7746, E-ISSN 1573-9708, Vol. 67, no 2-4, p. 255-263Article in journal (Refereed)
  • 14. Billström, Kjell
    et al.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    On the origin of the Yxsjöberg Cu-W skarn deposit, central Sweden: isotopic evidence1989In: Precambrian granitoids: petrogenesis, geochemistry and metallogeny : symposium : August 14-17, 1989, University of Helsinki, Finland. Abstracts / [ed] Ilmari Haapala; Yrjö Kähkönen, Espoo: Geological Survey of Finland , 1989, p. 14-Conference paper (Other academic)
  • 15.
    Billström, Kjell
    et al.
    Laboratory for Isotope Geology. Swedish Museum of Natural History, Stockholm.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    U-Pb zircon age of the Rostberget W-occurrence, northern Sweden1989In: Geologiska föreningens i Stockholm förhandlingar, ISSN 0016-786X, Vol. 111, no 2, p. 121-126Article in journal (Refereed)
    Abstract [en]

    Anomalously U-rich granites of the so-called Revsund type, associated with W- and Sn-enrichments, occur in the Gunnarn area close to Storuman in northern Sweden. At Rostberget, a swarm of thin undeformed wolframite-bearing greisen veins are situated in the interior of the Joran granite intrusion. We have dated zircons from a sample of the greisen veins with the U-Pb method. The veins are less than 1 cm wide and it is likely that the sample also contains zircons from the immediately surrounding altered granite. The mineralizing event and connected metasomatic processes probably released Zr from the granite which became available for zircon growth processes in the greisen veins. One notable feature, probably due to the greisen-forming processes, is the very high common Pb concentrations characterizing the zircons. By varying the assumed common Pb composition in the calculations, the effect on resulting intercept ages has been evaluated. The obtained age interval (1775-1782 Ma) is typical of formation ages for Revsund granites, which indicates that the mineralization event at Rostberget followed closely upon the granite emplacement. We conclude that the Revsund-type granites, which cover large areas, were generated in a narrow time interval 1790-1775 Ma ago.

  • 16.
    Blecken, Godecke-Tobias
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Rentz, Ralf
    Malmgren, Charlotte
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Stormwater impact on urban waterways in a cold climate: variations in sediment metal concentrations due to untreated snowmelt discharge2012In: Journal of Soils and Sediments, ISSN 1439-0108, E-ISSN 1614-7480, Vol. 12, no 5, p. 758-773Article in journal (Refereed)
    Abstract [en]

    Purpose: Stormwater discharges include contaminated sediments that accumulate in the receiving water body. It is thus important to investigate sediment and pollutant processes and pathways from the catchment to, and within, the receiving water. These processes may be influenced by seasonal changes. The objective of this study was to investigate the stormwater impact on receiving waters in the Luleå area, Northern Sweden; seasonal changes in contamination loads in the receiving waters due to snowmelt; and factors influencing the pollutant pathways in the receiving waters. Materials and methods: In front of three storm sewer outlets in Luleå, samples of bottom sediment (surface layer 0-2 cm) were collected from the connecting ditches and the downstream water body in autumn and spring (before and after the snow season 2009/2010). The characteristics of the receiving waters differed in geomorphology and vegetation. The sediment was analyzed for loss-on-ignition (LOI), grain size, and bulk concentrations of SiO 2, Al 2O 3, CaO, Fe 2O 3, MnO, Na 2O, P 2O 5, TiO 2, As, Cd, Co, Cr, Cu, Hg, Ni, Pb, S, V, and Zn. The sediment contamination was compared to concentrations at a reference point in Luleå where the bottom sediment was not affected by stormwater discharges and with Swedish environmental quality guidelines. Pearson's correlation and a principal component analysis were used to further evaluate the results. Results and discussion: Relative to the reference point, elevated trace metal concentrations were detected in sediments at all three sampling stations. At two of the stations, seasonal variations in ditch sediment grain size, LOI, and contaminant concentrations were observed, originating from stormwater sediment. Snowmelt runoff caused an increased proportion of fine-grained sediment fractions (<0.063 mm) in spring, mainly due to changes in runoff intensity and high sediment loads in the snowmelt runoff. The retention of metals appeared to be due to low turbulence in the water and the presence of organic material. Conclusions: Stormwater discharge affected the contaminant concentrations in the bottom sediments. The observed seasonal variation of contaminants indicated that relatively high amounts of contaminants are discharged during snowmelt and then reallocated within the receiving water body, either directly or after some temporal retention, depending on the characteristics of the receiving water. A calm water column and the presence of organic material in the receiving water body were crucial for the retention of metals

  • 17.
    Boman, Anton
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Engström, Emma
    Rodushkin, Ilya
    ALS Scandinavia AB.
    Åström, E.M.
    Linnaeus University, School of Natural Sciences, Kalmar.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Fe and Zn isotopic variations in Finnish acid sulfate soils2010In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 74, no 12/ Suppl 1, p. A102-Article in journal (Other academic)
  • 18. Boman, Anton
    et al.
    Engström, Emma
    Rodushkin, Ilya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Åström, Mats
    Linnéuniversitetet.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Isotopic variations of Fe and Zn in Finnish acid sulfate soils2010In: Proceedings of the 19th World Congress of Soil Science: Soil Solutions for a Changing World / [ed] RJ Gilkes; N Prakongkep, 2010, p. 1-4Conference paper (Refereed)
    Abstract [en]

    The use of a Neptune high-resolution MC-ICP-MS (Thermo Fisher Scientific) in this study has enabled high precision measurements of Fe and Zn isotopic ratios in Finnish acid sulfate soils in one near shore area (Vassor) and one inland area (Rintala).

  • 19. Carlsson, Eric
    et al.
    Holmström, Henning
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Water-solid interactions in tailings remediated by covering with till, Kristineberg Mine, northern Sweden1999In: Vol. 4, no 1, p. 511-Article in journal (Other academic)
  • 20.
    Carlsson, Erik
    et al.
    Luleå University of Technology.
    Thunberg, Jonas
    Luleå University of Technology.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Holmström, Henning
    Envipro Miljöteknik AB, Linköping.
    Sequential extraction of sulfide-rich tailings remediated by the application of till cover, Kristineberg mine, northern Sweden2002In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 299, no 1-3, p. 207-226Article in journal (Refereed)
    Abstract [en]

    A sequential extraction has been carried out on sulfide-rich mine tailings. The purpose was to investigate how elements released by oxidation are secondarily retained in the tailings and the possible consequences of the remediation. After investigating the solid tailings, seven samples were chosen for sequential extractions. Two samples were oxidised, situated just above the oxidation front; two samples from just below the former oxidation front with increased concentrations of several elements; two unoxidised samples were from an intermediate depth, and the deepest sample was from the tailings-peat boundary at the bottom of the impoundment. Five phases were extracted: adsorbed/exchangeable/carbonate; labile organics; amorphous Fe-oxyhydroxides/Mn-oxides; crystalline Fe-oxides; and organics/sulfides. The addition from dried porewater to the extracted fractions has been calculated and considered as minor. In the oxidised tailings, the sulfide fraction still dominates for elements such as Fe, S, Cd, Co, Cu, Hg and Zn, although the concentrations are low compared to the unoxidised tailings. Generally, the second most important fraction is the adsorbed/exchangeable/carbonate fraction. Below the oxidation front, the sulfide content of the tailings sharply increases. In the secondary enrichment zone, the total element concentrations increase compared with the deeper unoxidised samples, mainly due to secondary retention. For some elements, secondary retention is greater than the total amount extracted for the deeper unoxidised samples. In the secondary enrichment zone the adsorbed/exchangeable/carbonate fraction represents approximately 20 wt.% or more for Cd, Co, Mn, Ni and Zn. The amorphous iron oxyhydroxide or the crystalline iron oxide fractions are less important at this level, although for As, Ba and Cu the amorphous iron oxyhydroxide fraction represents up to 20 wt.. At the lower border of the enrichment zone, the total concentration for most metals is lower, but the importance of the adsorbed/exchangeable/carbonate fraction is further enhanced for Cd, Cu, Ni and Zn. These elements have 35-60 wt.% of the total amount from this fraction. For As, Cd, Cu, Ni and Pb, the secondary fractions extracted (extractions A-D) represent between 60 and 80 wt.% of the total content. At greater depth in the impoundment the relative importance of the adsorbed/exchangeable/carbonate fraction decreases, whilst the importance of amorphous iron oxyhydroxide and crystalline iron oxide fractions increases. The adsorbed/exchangeable/carbonate fraction is the most easily remobilised fraction. A raised groundwater table previously situated below the enrichment zone may result in the release of secondarily retained metals.

  • 21.
    Carlsson, Erik
    et al.
    Luleå tekniska universitet.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Holmström, Henning
    Envipro Miljöteknik AB, Linköping.
    Geochemistry of the infiltrating water in the vadose zone of a remediated tailings impoundment, Kristineberg, northern Sweden2003In: Applied Geochemistry, ISSN 0883-2927, E-ISSN 1872-9134, Vol. 18, no 5, p. 659-674Article in journal (Refereed)
    Abstract [en]

    At the remediated tailings Impoundment 1 at Kristineberg, Northern Sweden, installations of tension lysimeters were performed in the protective cover (10, 50, and 100 cm), in the oxidised tailings (150 cm), in the unoxidised secondarily enriched tailings (200 cm) and in the unoxidised tailings (260 cm). The lysimeters in the till protective cover contained relatively low concentrations of most elements. After infiltration through the sealing layer, consisting of 0.3 m compacted clayey till, pH decreased and conductivity, together with the concentrations of several major and trace elements, increased significantly. In the lysimeters installed in the tailings at depths of 150 and 200 cm average pH decreased to 3.4 at 150 cm and 3.2 at 200 and average conductivity increased to 2.9 mS/cm. Elements such as Al, Cd, Co, Fe, Mn, Mo, Ni,Pb, S, Si and Zn had the highest concentrations in the lysimeter at 200 cm depth. Examples of concentration averages for this lysimeter are Cd 600 μg/L, Fe 1500 mg/L, Mn 11 mg/L, Ni 1.06 μg/L, S 1800 mg/L, and Zn 190 mg/L. Between the depths of 200 and 260 cm the concentration of most elements decreased. The increase between the lysimeters at the depths of 150 and 200 cm can be explained by remobilization of secondarily retained oxidation products as well as from the continued oxidation. The decrease between the second and the third lysimeters is interpreted as co-precipitation with different Fe oxyhydroxides as well as adsorption onto secondarily formed minerals and primary mineral surfaces. Calculations of saturation indices indicate that several different hydroxides might precipitate at this level. This retainment takes place mainly due to the increase in pH. The pH increases from 3.2 up to 4-4.4 in this depth interval. Between the deepest lysimeter and the groundwater table, the element concentrations probably decrease even further. pH increases to 5-6.5 in the groundwater. Most of the pre-remediation oxidation products that are secondarily retained above or below the oxidation front and are released by the small amount of infiltrating water together with the present oxidation products are retained again during continued transport downwards. If the depth to the groundwater table is large enough, most of the metals released by the infiltrating water and the diffusing O2 do not reach the groundwater.

  • 22.
    Chlot, Sara
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Husson, Eva
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ecke, Frauke
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Effects on nutrient regime in two recipients of nitrogen-rich mine effluents in northern Sweden2013In: Applied Geochemistry, ISSN 0883-2927, E-ISSN 1872-9134, Vol. 31, p. 12-24Article in journal (Refereed)
    Abstract [en]

    The question of the limiting nutrient(s) for production of phytoplankton and macrophytes was explored in two contrasting freshwater systems receiving N- and P-rich mine effluents from the Boliden and Kiruna mine sites, northern Sweden. For both sites, total N (TN), total P (TP) and TN:TP mass ratios in water, sediment and macrophytes were used to examine (1) spatial variations within the systems, (2) differences between the systems and (3) seasonal variations. The TN concentration from the discharge point at the Kiruna site was about seven times higher than at the Boliden discharge point, while the TP concentration was 10 times lower than in the discharge point at the Boliden site. The majority of the studied lakes showed elevated biomass of phytoplankton, with maximum values found in Lake Bruträsket (Boliden). Mining activities have affected the nutrient regime of the two recipients by contributing to elevated TN and TP concentrations and TN:TP mass ratios as well as elevated production of phytoplankton and macrophytes compared to the reference sites. Depending on the NH4 concentration in the effluent at the Boliden site, water column TN:TP mass ratios shifted from being >22, indicating P-deficiency, to between 9 and 22, indicating a transition from N- to P-deficiency (co-limitation). However, water column TN:TP mass ratios at the Kiruna site always indicated P-deficiency, while TN:TP mass ratios of macrophytes indicate that both sites may vary from N- to P-limitation. The study suggests that for the design of efficient monitoring programmes and remediation measures, it is important to consider the major N and P species in water, phytoplankton, sediment and macrophytes.

  • 23.
    Chlot, Sara
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Siergieiev, Dmytro
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ecke, Frauke
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Husson, Eva
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Modelling nitrogen transformations in waters receiving mine effluents2011In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 409, no 21, p. 4585-4595Article in journal (Refereed)
    Abstract [en]

    This paper presents a biogeochemical model developed for a clarification pond receiving ammonium nitrogen rich discharge water from the Boliden concentration plant located in northern Sweden. Present knowledge about nitrogen (N) transformations in lakes is compiled in a dynamic model that calculates concentrations of the six N species (state variables) ammonium-N (Nam), nitrate-N (Nox), dissolved organic N in water (Norg), N in phytoplankton (Npp), in macrophytes (Nmp) and in sediment (Nsed). It also simulates the rate of 16 N transformation processes occurring in the water column and sediment as well as water–sediment and water–atmosphere interactions. The model was programmed in the software Powersim using 2008 data, whilst validation was performed using data from 2006 to 2007. The sensitivity analysis showed that the state variables are most sensitive to changes in the coefficients related to the temperature dependence of the transformation processes. A six-year simulation of Nam showed stable behaviour over time. The calibrated model rendered coefficients of determination (R2) of 0.93, 0.79 and 0.86 for Nam, Nox and Norg, respectively. Performance measures quantitatively expressing the deviation between modelled and measured data resulted in values close to zero, indicating a stable model structure. The simulated denitrification rate was on average five times higher than the ammonia volatilisation rate and about three times higher than the permanent burial of Nsed and, hence, the most important process for the permanent removal of N. The model can be used to simulate possible measures to reduce the nitrogen load and, after some modification and recalibration, it can be applied at other mine sites affected by N rich effluents.

  • 24.
    Chlot, Sara
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Carbon and nitrogen concentrations and isotopic composition in sediments of lakes receiving nitrogen rich mine effluents2011Conference paper (Refereed)
  • 25.
    Chlot, Sara
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Interaction between nitrogen and phosphorus cycles in mining-affected aquatic systems-experiences from field and laboratory measurements2013In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 20, no 8, p. 5722-5736Article in journal (Refereed)
    Abstract [en]

    The main objectives of this study were to (a) study the interaction between N and P cycles in mining-affected aquatic systems and (b) to quantify release rates of sedimentary soluble reactive phosphorus (SRP) that may be related to this interaction. Sediment cores and water from Lake Bruträsket (Boliden, northern Sweden) were collected and a time series of water sampling and flow measurements was conducted in the Brubäcken stream connected to the lake. Factors affecting SRP release were studied in a sediment incubation experiment and water column experiments. Field and laboratory measurements indicated that pH and dissolved oxygen are two important factors for SRP release. At the end of the low-oxygen incubation, an SRP concentration of 56 μg L-1 resulted in a sedimentary flux of 1.1 mg SRP m-2 day-1. This is ∼10 times higher than the flux of 0.12 mg SRP m-2 day-1 obtained from depth integration of vertical SRP profiles measured in the lake, and ∼100 times higher than the external flux of 0.014 mg SRP m-2 d-1 into the lake (based on catchment area). Field measurements indicated that oxidation of organic matter and mining-related chemicals (ammonium and thiosulphates) may result in increased internal SRP flux from the sediment. Increased P loading in the lake as a result of low-oxygen conditions could change water column total nitrogen/total phosphorus ratios from 27 to 17, consequently changing the lake from being P-limited to be co-limited by N and P. The obtained findings point to possible interaction between the cycles of nitrogen (oxygen consumption) and P (flux from sediment) that may be important for nutrient regulation in mine water recipients.

  • 26. Chlot, Sara
    et al.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Nitrogen uptake and cycling in Phragmites australis in a lake-receiving nutrient-rich mine water: a 15 N tracer study2015In: Environmental Earth Sciences, ISSN 1866-6280, E-ISSN 1866-6299, Vol. 74, no 7, p. 6027-6038Article in journal (Refereed)
    Abstract [en]

    Uptake and cycling of nitrogen (N) in the littoral zone of a lake-receiving nutrient-rich mine water located in Boliden, northern Sweden, was investigated. Stable isotope tracer solutions of 15N as NH4 + (NAM mesocosm) or NO3 − (NOX mesocosm) were added to mesocosms enclosing plants of common reed (Phragmites australis). The 15N abundance in various plant parts was measured at pre-defined time intervals over an experimental period of 22 days. During the course of the experiment, plant parts from the NAM mesocosms were significantly more enriched in 15N than plant parts from the NOX mesocosms. On day 13, Δδ15N values of the fine roots from the NAM mesocosms had reached +8220 ‰, while the maximum Δδ15N value in NOX roots was considerably lower at +4430 ‰. Using 15N values in macrophyte tissues present at the end of the experiment enabled calculations of uptake rates and % of tracer N recovered in the plant (%tracerNrecov). Maximum tracer uptake rates were higher for the NAM mesocosms (1.4 µg g−1 min−1 or 48 mg N m−2 d−1) compared to the NOX mesocosms (0.23 µg g−1 min−1 or 8.5 mg N m−2 d−1). Calculations of %tracerNrecov indicated that 1–8 and 25–44 % of added N was assimilated by plants in the NOX and NAM mesocosms, respectively. Hence, P. australis was more effective in assimilating NH4 +, and a larger portion of the tracer N accumulated in the roots compared to the other plant parts. Consequently, macrophyte N removal is most effective for cold-climate aquatic systems receiving mine water dominated by NH4 +. For permanent removal of N, the whole plant (including the roots) should be harvested.

  • 27.
    Chlot, Sara
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Studying nitrogen cycling and uptake by macrophytes using 15N tracer techniques2011Conference paper (Refereed)
  • 28.
    Elming, Sten-åke
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    A palaeomagnetic and geochemical study of mafic dikes in northern Sweden1990In: Abstracts: Second Symposium on the Baltic Shield with Workshop on Correlation with Laurentia, Lund, Sweden June 5-7, 1990, Lund: International Geological Correlation Programme , 1990, p. 34-Conference paper (Other academic)
  • 29.
    Engström, Emma
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Rodushkin, Ilya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Baxter, Douglas
    Ingri, Johan
    Öhlander, Björn
    Characterization of the silicon isotopic composition of the terrestrial biogenic output from a boreal forest in Northern Sweden2007In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 71, no 15s, p. A256-Article in journal (Other academic)
    Abstract [en]

    During the last decade, the potential plant impact on the biogeochemical cycle of Si via the large terrestrial biogenic Si reservoir formed by vegetation has attracted considerable interest. It has been concluded that the release of silicic acid from dissolution of soil phytoliths might exceed the Si mobilized by weathering of Si-containing primary minerals, which implies that the biogenic contribution to the total content of Si in the soil profile must be considered in weathering studies. Information about Si isotopes can potentially be used for differentiation between relative contributions from biogenic and mineral sources in natural waters, soil solutions and plants. This would, however, require thorough characterization of the terrestrial biogenic Si reservoir, a task that received somewhat limited attention to date. The aim of the present study was to characterize the Si isotopic composition of a boreal forest, with bedrock consisting of dolomitic limestone, in Northern Sweden. Representative biomass from the forest area exhibited a surprisingly homogenous Si isotopic composition, ranging from δ29Si (-0.14 ± 0.05)‰ (2σ) to (0.13 ± 0.04)‰. Further, a change in the Si isotopic composition of (+0.39 ± 0.04)‰ has been detected in Leymus arenarius, indicating predominant accumulation of heavier isotopes from spring to autumn. Recent studies of Si isotopic composition in plants have been focused on the root uptake of dissolved silicic acid as the only Si accumulation path. Results acquired during the present study provide compelling evidence to suggest that exogenous Si is also incorporated in the surface structure of the plant material. A surface contribution in excess of 5% of the total Si would introduce a significant shift in the bulk isotopic composition (>0.1‰) assuming that the exogenous material differed by 2‰ from the biogenic Si. This strongly suggests that the surface contribution must be carefully considered during in situ uptake studies.

  • 30.
    Engström, Emma
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Rodushkin, Ilya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Baxter, Douglas
    Öhlander, Björn
    Chromatographic purification for the determination of dissolved silicon isotopic composition in natural waters by high-resolution multicollector inductively coupled plasma mass spectrometry2006In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 78, no 1, p. 250-257Article in journal (Refereed)
    Abstract [en]

    A procedure is described for accurate Si isotope ratio measurements by multicollector inductively coupled plasma mass spectrometry (MC-ICPMS). Dissolved silicon was preconcentrated and separated from other elements present in natural surface waters using anion-exchange chromatography. The optimized procedure provides virtually complete elimination of major inorganic constituents while maintaining Si recovery in excess of 97%. High-resolution capabilities of MC-ICPMS used in this study allow interference-free measurements of 28Si and 29Si isotopes using conventional solution nebulization sample introduction without aerosol desolvation. Owing to the magnitude of polyatomic ion contributions in the region of mass 30, mostly from 14N16O+, measurements of the 30Si isotope can be affected by tailing of the interference signals, making exact matching of analyte and nitric acid concentrations in all measurement solutions mandatory. Isotope abundance ratio measurements were performed using the bracketing standards approach and on-line correction for mass-bias variations using an internal standard (Mg). Uncertainties, expressed as 95% confidence intervals, for replication of the entire procedure are better than ±0.18" for δ29Si and ±0.5" for δ30Si. For the first time with MC-ICPMS, the quality of Si isotope abundance ratio measurements could be verified using a three-isotope plot. All samples studied were isotopically heavier than the IRMM-018 Si isotopic reference material.

  • 31.
    Engström, Emma
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Rodushkin, Ilya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ingri, Johan
    Baxter, Douglas
    Ecke, Frauke
    Österlund, Helene
    Öhlander, Björn
    Temporal isotopic variations of dissolved silicon in a pristine boreal river2010In: Chemical Geology, ISSN 0009-2541, E-ISSN 1872-6836, Vol. 271, no 3-4, p. 142-152Article in journal (Refereed)
    Abstract [en]

    It has previously been concluded that the stable Si isotopes are fractionated during geochemical and biogeochemical elemental transfers, such as weathering and precipitation of clays and biogenic Si, which has opened up the possibility of using Si as a tracer in natural terrestrial ecosystems. Furthermore, quantification of the biogenic impact on the biogeochemical Si cycle has attracted significant scientific interest since biological control has been suggested. Previous observations of seasonal variations in the dissolved Si isotopic pattern further imply that high-frequency riverine sampling during main hydrological events might provide important information about natural processes governing the fluvial biogeochemical Si cycle.Therefore, temporal variations in the isotopic composition of riverine dissolved Si were investigated for the Kalix River, Northern Sweden, the largest pristine river system in Europe, based on high-frequency sampling during a period of 25 weeks from early April to early October 2006. Temporal variations spanning 0.4‰ for δ29Si and 0.8‰ for δ30Si of dissolved Si in the Kalix River were observed during the period, suggesting that the riverine dissolved Si input to the oceans cannot be considered to have a constant Si isotopic composition even on a short time scale.The results implicate biogeochemical Si-cycling via formation and dissolution of biogenic silica as processes significantly affecting the dissolved Si transport in boreal systems during April to early October. The Si budget in the river system appeared to be controlled by relative Si enrichment during high discharge events and relative Si depletions in the subarctic mountainous and lake dominated areas. The Si enrichments and depletions were accompanied by decreasing and increasing riverine δ29Si and δ30Si, respectively. These isotope variations can be explained by release of plant derived silica, depleted in heavier Si isotopes, during the spring snowmelt. Further, increased volumetric contribution from the headwater and losses of dissolved Si due to biogenic silica formation by diatoms in the subarctic lakes at a later period are expected to be responsible for the preferential losses of lighter isotopes, as further verified by land cover analysis

  • 32. Engström, Emma
    et al.
    Rodushkin, Ilya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ingri, Johan
    Baxter, Douglas
    Ecke, Frauke
    Österlund, Helene
    Öhlander, Björn
    Temporal isotopic variations of dissolved silicon in a pristine boreal river2009In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 73, no 13, Suppl. S, p. A333-Article in journal (Other academic)
    Abstract [en]

    Interest in quantifying the biogenic impact on the terrestrial biogeochemical Si cycle has increased significantly since biological control has been suggested. Previous observations of isotopic fractionation of Si during biogeochemical and geochemical processes imply that seasonal dissolved Si isotopic patterns in rivers have the potential for use in extracting information about the riverineand terrestrial biogeochemical Si cycles.Therefore, variations in the isotopic composition of dissolved riverine Si were investigated for the Kalix River, Northern Sweden, one of the largest pristine rivers in Europe, based on high-frequency sampling during a period of 25 weeks from early April to early October 2006. Temporal variations spanning 0.4. for δ29Si and 0.8. for δ30Si of dissolved Si in the Kalix River were observed during the period, suggesting that the riverine Si input to the oceans cannot be considered to have a constant Si isotopic composition even on a short time scale. The results implicate biogeochemical Si-cycling via formation and dissolution of biogenic silica as major processes controlling the Si transport in boreal systems. The Si budget in the river system appeared to be controlled by relative Si accretions during high discharge events and relative Si depletions in the subarctic mountainous and lake dominated areas. There were also temporal variations in Si isotopic composition with accretion (relative Si contribution), accompanied by depletion of the heavier Si isotopes, while the opposite trend was observed during periods of riverine Si depletion. These isotope variations can be explained by release of plant derived silica, depleted in heavier Si isotopes, during the spring snowmelt. Further, increased volumetric contribution from the headwater and losses of Si due to biogenic silica formation by diatoms in the subarctic lakes at a later period are expected to be responsible for the preferential losses of lighter isotopes. These conclusions are further verified by land cover analysis.

  • 33. Engström, Emma
    et al.
    Rodushkin, Ilya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Ingri, Johan
    Baxter, Douglas
    Silicon isotopic composition of boreal forest vegetation in Northern Sweden2008In: Chemical Geology, ISSN 0009-2541, E-ISSN 1872-6836, Vol. 257, no 3-4, p. 247-256Article in journal (Refereed)
    Abstract [en]

    Thorough characterization of the Si isotopic composition of the terrestrial biogenic pool could potentially allow Si isotope information to be used when assessing the relative contributions from biogenic and mineral sources to soil water, plants and surface waters. In the present study, the Si isotopic compositions of major biomass components in a boreal forest in Northern Sweden were investigated, along with the relative contributions from exogenous Si incorporated in the plant structure. This was achieved using chemical purification and high-resolution multi-collector inductively coupled mass spectrometry (MC-ICP-MS) for the precise and accurate determination of the Si isotopic composition of plants. The technique, which relies on multi-elemental analysis of plant ashes and sample-specific HF-dissolution followed by strong-anion exchange chromatography, allows efficient separation of Si from matrix and interfering elements, while recovering in excess of 99% Si. The long-term instrumental reproducibility, expressed as two standard deviations (2σ), for the isotopic reference material NBS28 (n=12) was 0.06‰ for δ29Si and 0.12‰ for δ30Si. Results for the analyses of composite plant samples for the eight most prolific species in the boreal forest yielded a surprisingly homogenous Si isotopic composition, expressed as δ29Si (±expanded combined uncertainty) and δ30Si, ranging from (-0.15±0.11)‰ to (0.13±0.06)‰ and (-0.31±0.08)‰ to (0.22±0.13)‰, respectively. Isotopic and elemental analyses of local airborne particulate material suggest that the exogenous Si contribution varies between >1% and >70%, indicating that the potential surface contribution must be considered during Si uptake studies. The present study thus provides evidence that thorough appreciation of the forms of Si in plants is an absolute requirement when assessing the plant impact on the Si cycle via the difference in dissolution kinetics for phytoliths and lithogenic Si.

  • 34. Frandsen, Sara
    et al.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Herbert, Roger
    Institutionen för geovetenskaper, Uppsala Universitet.
    Öhlander, Björn
    Nitrogen effluents from mine sites in Northern Sweden: environmental effects and removal of nitrogen in recipients2009In: 8th International Conference on Acid Rock Drainage (ICARD) and Securing the Future: Mining, Metals & the Environment in a Sustainable Society 2009: Skelleftea, Sweden, 22 - 26 June 2009, Red Hook, NY: Curran Associates, Inc., 2009Conference paper (Refereed)
  • 35.
    Gustavsson, Håkan
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Weihed, Pär
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Nordlund, Erling
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Forsling, Willis
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Forssberg, Eric
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Norrländsk vattenkraft och gruvnäring: två svenska välståndsbyggare2009In: Thule: Kungl. Skytteanska samfundets årsbok 2009, Umeå: Kungl. Skytteanska samfundet , 2009, p. 331-345Chapter in book (Other (popular science, discussion, etc.))
  • 36.
    Heijne, Patrik von
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Maurice, Christian
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Adaptive sampling strategies to improve site assessment2010In: ConSoil 2010: 22 - 24 September 2010 Salzburg, Austria; proceedings 11th International UFZ-Deltares - TNO Conference on Management of Soil, Groundwater & Sediments in cooperation with Land Salzburg ..., Leipzig: UFZ , 2010Conference paper (Refereed)
    Abstract [en]

    In an adaptive sampling strategy based on multi-stage sampling, information gathered in earlier stages is used to choose what information to search for in the next stage. This should be the information that has the greatest probability to best improve the basis for the decisions to be made. Based on literature this paper discusses how to use this strategy to improve investigations of contaminated soil by assessing decision uncertainty. The measurement error, the number of samples and choice of interpolation method are among the factors that have large effect on the usability of the outcome of a multi-stage sampling investigation using interpolation. In the light of increased usage of field-portable test instruments the interaction of measurement error and number of samples needs to be further investigated. Other issues that need attention are how to measure the quality of the basis for decision and how to decide when the quality is good enough.

  • 37.
    Heijne, Patrik von
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Maurice, Christian
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Reporting data: managing sampling and analytical uncertainty2014In: Contaminated Soils: A Guide to Sampling and Analysis, London: Future Science Ltd , 2014, p. 88-101Chapter in book (Refereed)
  • 38.
    Holmström, Henning
    et al.
    Luleå tekniska universitet.
    Carlsson, Erik
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Groundwater composition within tailings remediated by covering with till, Kristineberg Mine, northern Sweden1999In: Vol. 4, no 1, p. 511-512Article in journal (Other academic)
  • 39.
    Holmström, Henning
    et al.
    Luleå University of Technology.
    Ljungberg, J.
    Luleå University of Technology.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Role of carbonates in mitigation of metal release from mining waste: evidence from humidity cells tests1999In: Environmental Geology, ISSN 0943-0105, E-ISSN 1432-0495, Vol. 37, no 4, p. 267-280Article in journal (Refereed)
    Abstract [en]

    Leaching of two contrasting types of sulphidic tailings in humidity cells has been performed. The release of heavy metals and the oxidation rate have been studied. Tailings from the Laver mine contain a few percent sulphides and lack carbonates, whereas tailings from the Stekenjokk mine are both sulphide- and carbonate-rich. The results showed that in the leachates from the Laver samples, the metal concentrations increased and pH decreased with time, indicating an increased oxidation rate. In the Stekenjokk samples, pH remained high during the experiment, thereby keeping the metal concentrations low in the leachates. The oxidation rate also decreased with time, probably due to Fe-hydroxide coatings on sulphide surfaces. The results show that addition of carbonates and the maintenance of a high pH not only reduce the solubility of heavy metals, but also decrease the oxidation rate of sulphides.

  • 40.
    Holmström, Henning
    et al.
    Luleå tekniska universitet.
    Ljungberg, Johan
    Luleå tekniska universitet.
    Ekström, M.
    Analytica AB.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Secondary copper enrichment in tailings at the Laver mine, northern Sweden1999In: Environmental Geology, ISSN 0943-0105, E-ISSN 1432-0495, Vol. 38, no 4, p. 327-342Article in journal (Refereed)
    Abstract [en]

    Field and laboratory studies of the sulphide-bearing tailings at Laver, northern Sweden, show that the present release of metals from the tailings is low, especially with regard to Cu. A large part of the Cu released by sulphide oxidation is enriched in a distinct zone just below the oxidation front. The enrichment zone occurs almost all over the tailings area except in areas with a shallow groundwater table. The Cu enrichment is caused by formation of covellite and adsorption onto mineral surfaces. The transport of Zn, Co, Cd, Ni and S seems to be controlled mainly by adsorption. No secondary zone or secondary minerals containing these metals have been found. Just below the groundwater table, metals are released into solution when the enrichment zone reaches the groundwater due to the low pH. An increased release of metals, especially Cu, can be expected in the future, since the enrichment zone is moving towards the groundwater table.

  • 41. Holmström, Henning
    et al.
    Ljungberg, Johan
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Secondary metal enrichments in the tailings of the Laver mine1996In: Jubilee issue: short papers and abstracts for the Jubilee meeting "Current problems, ideas and results in geology" : Stockholm 16th-18th October 1996 at the celebration of the 125th anniversary of the Geological society of Sweden / [ed] Björn Sundquist, Geologiska föreningen , 1996, p. 86-87Conference paper (Other academic)
  • 42.
    Holmström, Henning
    et al.
    Luleå University of Technology.
    Ljungberg, Johan
    Luleå University of Technology.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    The character of the suspended and dissolved phases in the water cover of the flooded mine tailings at Stekenjokk, northern Sweden2000In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 247, no 1, p. 15-31Article in journal (Refereed)
    Abstract [en]

    Studies of the suspended and dissolved phases of the pond water, material collected from sediment traps, and surficial sediments/tailings from the flooded tailings pond at Stekenjokk have been performed. The aim was to characterise the material, to study the seasonal variations and to quantify possible resuspension of the tailings in the pond. The element concentrations in the pond at Stekenjokk seem to be largely controlled by processes controlling the precipitation and dissolution of Mn- and Fe-oxyhydroxides in both the water column and in the surficial tailings. Physiochemical processes such as weathering of silicates on the surrounding mountain slopes or dykes contributes both dissolved elements and detrital particles. The suspended phase consists of detrital silicate material as well as Fe- and Mn-oxyhydroxides. The average heavy metal concentrations are high, e.g. 0.42% Cu, 0.15% Pb and 3.1% Zn, which is probably due to sorption onto Fe- and Mn-oxyhydroxides. The suspended phase is richer in Fe, and particularly Mn, during the winter. The suspended phase resembles the material collected in sediment traps and the material in the surficial sediments. The pond water is well mixed during the ice-free season. The dissolved heavy metal concentrations are generally rather low with, e.g. maximum concentrations of 2.03 μg/l Cu, 0.23 μg/l Pb and 268 μg/l Zn during the winter. Higher dissolved concentrations are found below the ice-cover above the sediment surface during the winter, caused by diffusion of elements from the sediment-water interface up into the pond water. Most of the metals occurring in the pond are dissolved and resuspension of tailings is negligible.

  • 43.
    Holmström, Henning
    et al.
    Luleå tekniska universitet.
    Salmon, Ursula
    Royal Institute of Technology.
    Carlsson, Erik
    Luleå tekniska universitet.
    Paraskev, Petrov
    Sofia University.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Geochemical investigations of sulfide-bearing tailings at Kristineberg, northern Sweden, a few years after remediation2001In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 273, no 1-3, p. 111-113Article in journal (Refereed)
    Abstract [en]

    In the Kristineberg mining area in northern Sweden, massive, pyrite-rich Zn-Cu ores are intercalated in ca. 1.9 Ga volcano-sedimentary rocks. Investigations of a tailings impoundment remediated by means of both till coverage and raising the groundwater table have been undertaken. The aim of the study was to characterise the tailings with respect to mineralogy, the chemical composition of both the tailings and the pore water, and to try to identify the significant reactions that may have occurred before and after remediation. It was found that the oxidation front had reached down to depths of between approximately 0.1 and 1.15 m before remediation. The oxidation of sulfides has produced high concentrations of some metals in the pore water; up to 26, 16, 4.1, 2.7 and 82 mg/l have been measured for Al, Mn, Fe and Zn, respectively. Concentrations of metals such as Cd, Co, Cu, Ni and Pb are lower, with average concentrations of 18.4, 83.8, 45, 79.6 and 451 μg/l, respectively. Higher concentrations of major elements such as Ca, Fe, Mn, Mg and S have been measured at depth in pore water than at shallower levels. This is probably caused by flush out of elements after remediation and vertical transport from the upper parts before remediation. The pH is relatively high, approximately 5.5 at most depths in the tailings, except in and around the former oxidation zone where it is lower, and where the highest dissolved concentrations of elements such as As, Cd, Co, Cu, Pb and Zn occur. This is probably due to the release of metals secondarily retained below the oxidation front prior to the remediation. Since the groundwater table is raised, the groundwater reaches the retained metals, which leads to desorption of metals and dissolution of secondary minerals.

  • 44.
    Holmström, Henning
    et al.
    Luleå tekniska universitet.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Layers rich in Fe- and Mn-oxyhydroxides formed at the tailings-pond water interface, a possible trap for trace metals in flooded mine tailings2001In: Journal of Geochemical Exploration, ISSN 0375-6742, E-ISSN 1879-1689, Vol. 74, no 1-3, p. 189-203Article in journal (Refereed)
    Abstract [en]

    Geochemical field studies of the flooded sulphide-rich mine tailings at Stekenjokk in northern Sweden have been performed. Minor diffusion of elements from the tailings to the pond water is occurring. The diffusion rate is higher where tailings that were oxidised before the flooding have been deposited. Layers rich in Fe-and Mn-oxyhydroxides have been developed close to the tailings surface, and a layer of natural sediments rich in organic material have developed on the tailings surface since the flooding. The oxyhydroxides adsorb and/or co-precipitate metals and function as a trap for released metals at the tailings-pond water interface, thereby decreasing the diffusion rate from the tailings pore water to the pond water at the sediment-water interface. This study shows that it is possible for a deposit of flooded tailings to reach a state when it almost functions as a natural lake in northerly areas, with Fe-and Mn-oxyhydroxide layers controlling the diffusion of metals into the overlying pond water, within a relatively short time after remediation

  • 45.
    Holmström, Henning
    et al.
    Luleå University of Technology.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Oxygen penetration and subsequent reactions in flooded sulphidic mine tailings: a study at Stekenjokk, northern Sweden1999In: Applied Geochemistry, ISSN 0883-2927, E-ISSN 1872-9134, Vol. 14, no 6, p. 747-759Article in journal (Refereed)
    Abstract [en]

    A study of O2 penetration and pore water geochemistry of the flooded tailings at Stekenjokk has been performed. The results show that there is a diffusion of elements from the tailings pore water to the overlying water. The presence of elements such as Ca, Mg, S, Si, Ba and Sr are likely the result of diffusion of older process water trapped in the tailings. Oxygen concentrations in the tailings measured with microelectrodes show that there is O2 available down to 16 to 17 mm depth in the tailings. Pore water analyses show that there are subsurface maxima for the elements Cu, Zn, Ni, Co and Cd at depths of 0.25 to 2.75 cm. The highest concentrations of almost all elements were found where previously oxidised material was deposited before the flooding. Lower pH is measured in the uppermost part of the tailings compared with the pond water and the tailings pore water at depth. Oxidation of sulphides in the uppermost part of the tailings is probably occurring. A decrease in oxidation rate can be expected in the future due to deposition of organic material at the tailings surface. Flooding seems to be an efficient remediation method at Stekenjokk.

  • 46.
    Ingri, Johan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Andersson, Per S
    Widerlund, Anders
    Öhlander, Björn
    Gustafsson, Örjan
    Land, Magnus
    The Ce-anomaly in river suspended matter: An indicator of hydrogeochemical processes in a boreal catchment2000In: Vol. 5, no 2, p. 540-Article in journal (Other academic)
  • 47.
    Ingri, Johan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Gelting, Johan
    Nordblad, Fredrik
    Engström, Emma
    Rodushkin, Ilya
    Andersson, P.S.
    Oxford University.
    Porcelli, D.
    Oxford University.
    Gustafsson, O.
    Stockholms Universitet.
    Semiletov, I.
    University of Alaska.
    Öhlander, Björn
    Fractionation of iron isotopes during estuarine mixing in Ob, Yenisey and Lena freshwater plumes2009In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 73, no 13, Suppl. S, p. A569-Article in journal (Other academic)
    Abstract [en]

    Iron isotopes were measured in suspended matter (>0.2 µm) in the Ob, Yenisey and Lena River freshwater plumes during the International Siberian Shelf Study 2008 (ISSS-08). The δ56Fe value was around zero within the Lena River and close to the river mouth, but changed to more negative values in the outer parts of the plume. In both the Ob and Yenisey plumes suspended matter in the surface water had clearly negative values whereas samples close to the bottom showed values close to zero.It has previously been suggested that total Fe in river suspended matter (>0.2µm) in boreal regions is roughly a mixture of three phases, detrital particles (δ56Fe around zero), oxyhydroxide particles (δ56Fe positive) and C-Fe particles (δ56Fe negative). We suggest that the δ56Fe pattern observed in this study is the result of relatively rapid removal of detrital particles and Fe-oxyhydroxides, leaving a suspended fraction with negative values in the surface water in the outer parts of the freshwater plumes. Hence, during estuarine mixing of suspended particles heavy iron isotopes are deposited close to the river mouth, whereas light isotopes are exported to open ocean water.

  • 48.
    Ingri, Johan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Pontér, Christer
    Öhlander, Björn
    Löfvendahl, Runo
    Boström, Kurt
    Environmental monitoring with river suspended matter: case study in the River Dalälven, central Sweden1993In: Applied Geochemistry, ISSN 0883-2927, E-ISSN 1872-9134, Vol. 8, no Suppl. 2, p. 125-130Article in journal (Refereed)
    Abstract [en]

    Heavy metal concentrations are presented for suspended sediment from the River Dalälven, central Sweden. The river is contaminated by acid mine drainage and data from the most polluted tributary, Garpenbergsån, are also presented. Element/Al ratios in the suspended phase showed that K, Mg and Ti were mainly hosted in detrital particles together with a large fraction of Si. Between 50 and 60% of the load of Fe, Ca and Na were in non-detrital form. Less than 10% of the total load of suspended Mn and P were in a detrital form. The sediment in the River Dalälven is polluted by As, Cr, Cu, Hg, Ni, Pb and Zn. These elements, except Pb, showed an even stronger enrichment in the suspended phase. This indicated that between one third and one half of the suspended load was recirculated to the water column during sedimentation. Arsenic, Cr, Cu, Hg, Ni, Pb and Zn showed linear correlations with non-detrital Fe, close to the inflow of the polluted stream Garpenbergsån. Deposition of non-detrital Fe, Na, Cr, Cu and Ni in the sedimentation basins close to the river mouth reduced the suspended discharge of these elements to the Baltic Sea. However, the basins acted as sources for non-detrital suspended As, Hg, Pb, and Zn during the studied period. The calculated net export, in a non-detrital form, for these elements was 141, 3.7, 1100 and 7000 kg, respectively as measured between May and October.

  • 49. Ingri, Johan
    et al.
    Widerlund, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Land, Magnus
    Luleå University of Technology.
    Gustafsson, Örjan
    Luleå University of Technology.
    Andersson, Per
    Luleå University of Technology.
    Öhlander, Björn
    Temporal variations in the fractionation of the rare earth elements in a boreal river: the role of colloidal particles2000In: Chemical Geology, ISSN 0009-2541, E-ISSN 1872-6836, Vol. 166, no 1-2, p. 23-45Article in journal (Refereed)
    Abstract [en]

    Rare earth element (REE) data from weekly sampling of the filtered (<0.45 μm) and suspended particulate phase during 18 months in the Kalix River, Northern Sweden, are presented together with data on colloidal particles and the solution fraction (<3 kDa). The filtered REE concentration show large seasonal and temporal variations in the river. Lanthanum varied between approximately 300 and 2100 pM. High REE concentration in the filter-passing fraction is related to increased water discharge and there is a strong correlation between the REE concentration, organic carbon, Al and Fe. Physical erosion of detrital particles plays a minor role for the yearly transport of particulate REE in this boreal river system. The suspended particulate fraction, which is dominated by non-detrital fractions, accounted for only 35% of the yearly total transport of La in the river. Approximately 10% of the REE were transported in detrital particles during winter. At spring-flood in May, about 30% of the LREE and up to 60% of the HREE where hosted in detrital particles. Ultrafiltration of river water during spring-flood shows that colloidal particles dominate the transport of filter-passing REE. Less than 5% of the filtered REE are found in the fraction smaller than 3 kDa. The colloidal fraction shows a flat to slightly LREE enriched pattern whereas the solution fraction (<3 kDa) show an HREE enriched pattern, compared with till in the catchment. Suspended particles show a LREE enriched pattern. Data indicate that the REE are associated with two phases in the colloidal (and particulate) fraction, an organic-rich phase (with associated Al-Fe) and an Fe-rich (Fe-oxyhydroxide) inorganic phase. The Ce-anomaly in the suspended particulate fraction in the river shows systematic variations, and can be used to interpret fractionation processes of the REE during weathering and transport. There was no anomaly at maximum spring-flood but during the ice-covered period the anomaly became more and more negative. The temporal and seasonal variations of the Ce-anomaly in the suspended particulate phase reflect transport of REE-C-Al-Fe-enriched colloids from the upper section of the till (and/or from mires) to the river at storm events.

  • 50.
    Ingri, Johan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Widerlund, Anders
    Land, Magnus
    Öhlander, Björn
    Andersson, P.S.
    Gustafsson, Ö.
    Seasonal variations of the rare earth elements in a boreal river1998In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 62A, p. 681-682Article in journal (Other academic)
12345 1 - 50 of 237
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf