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Åhlgren, K., Sjöberg, V., Grawunder, A., Allard, B. & Bäckström, M. (2020). Chemistry of Acidic and Neutralized Alum Shale Pit Lakes 50 Years After Mine Closure, Kvarntorp, Sweden. Mine Water and the Environment
Open this publication in new window or tab >>Chemistry of Acidic and Neutralized Alum Shale Pit Lakes 50 Years After Mine Closure, Kvarntorp, Sweden
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2020 (English)In: Mine Water and the Environment, ISSN 1025-9112, E-ISSN 1616-1068Article in journal (Refereed) Epub ahead of print
Abstract [en]

Several large pits were left after alum shale was mined from 1942 to 1966 in the Kvarntorp area of Sweden. Of these, the pit lakes Polen and Norrtorpssjon are the focus of this study. They have elevated levels of Na, K, Mg, Ca, Al, Mn, Fe, and sulphate, as well as trace elements, from weathering of the exposed shale. Both lakes had a stable pH below 4 until 1996 when the pH in Norrtorpssjon started to increase, exceeding 8 in 2010, due to inflow of leachates from alkaline waste dumped in an adjacent waste deposit, similar to a large scale anoxic limestone drain (ALD). Iron and Al concentrations decreased as the pH increased, indicating formation of particulate species which accumulate as sediments. The Co, Ni, and Zn concentrations also decreased, probably due to association with the solid phases, while Cu was less affected by the increase in pH, possibly due to formation of complexes with dissolved organic matter. Vanadium concentrations show limited solubility, while Mo concentrations increased at higher pH. Uranium concentrations decreased from above 80 mu g/L to below 10 mu g/L before rising to 30-35 mu g/L due to the formation of soluble carbonate complexes at higher pH levels. The elevated levels of Li, Sr, and U indicate that weathering has continued despite the pH change. Both pit lakes are stratified, but no seasonal overturn has been observed. Long-term behaviour of this large-scale ALD and its implications are also discussed.

Place, publisher, year, edition, pages
Springer, 2020
Keywords
Weathering, Leachate, Sediment, Vanadium, Molybdenum, Uranium
National Category
Environmental Sciences
Identifiers
urn:nbn:se:oru:diva-80750 (URN)10.1007/s10230-020-00665-y (DOI)000516394800001 ()
Note

Funding Agencies:

Örebro University  

SAKAB-Kumla Foundation  

Available from: 2020-03-20 Created: 2020-03-20 Last updated: 2020-03-20Bibliographically approved
Åhlgren, K., Sjöberg, V. & Bäckström, M. (2018). Leaching of U, V, Ni and Mo from Alum Shale Waste as a Function of Redox and pH - Suggestion for a Leaching method. In: Wolkersdorfer, Ch., Sartz, L., Weber, A., Burgess, J. and Tremblay, G. (Ed.), Mine Water: Risk to Opportunity. Paper presented at 11th ICARD, IMWA, WISA MWD 2018 Conference – Risk to Opportunity, Pretoria, South Africa, 10-14 September, 2018 (pp. 782-787). Pretoria, South Africa: Tshwane University of Technology, II
Open this publication in new window or tab >>Leaching of U, V, Ni and Mo from Alum Shale Waste as a Function of Redox and pH - Suggestion for a Leaching method
2018 (English)In: Mine Water: Risk to Opportunity / [ed] Wolkersdorfer, Ch., Sartz, L., Weber, A., Burgess, J. and Tremblay, G., Pretoria, South Africa: Tshwane University of Technology , 2018, Vol. II, p. 782-787Conference paper, Published paper (Refereed)
Abstract [en]

Alum shale residues in the form of nes and ash were leached at di erent pH and redox conditions. Total concentrations and mineral analysis indicate loss of some elements in burned shale, and redistribution of others. Uranium and nickel were shown to be more leachable from nes than from ashes. Decreased pH favoured leaching of Ni, U and V, whereas increased pH resulted in increased leaching of molybdenum. Redox conditions a ected leaching of Mo and V, but not U and Ni. us the method can be used as an estimate for leaching at di erent redox and pH conditions.

Place, publisher, year, edition, pages
Pretoria, South Africa: Tshwane University of Technology, 2018
Keywords
Kvarntorp, alum shale, leaching, uranium, vanadium
National Category
Geochemistry
Research subject
Chemistry
Identifiers
urn:nbn:se:oru:diva-71961 (URN)978-0-620-80650-3 (ISBN)
Conference
11th ICARD, IMWA, WISA MWD 2018 Conference – Risk to Opportunity, Pretoria, South Africa, 10-14 September, 2018
Available from: 2019-01-30 Created: 2019-01-30 Last updated: 2019-03-26Bibliographically approved
Åhlgren, K., Sjöberg, V., Sartz, L. & Bäckström, M. (2017). Understanding Groundwater composition at Kvarntorp, Sweden, from leaching tests and multivariate statistics. In: Wolkersdorfer, C.; Sartz, L.; Sillanpää, M.; Häkkinen, A. (Ed.), 13th International Mine Water Association Congress – Mine Water & Circular Economy: Proceedings, Volume 2. Paper presented at 13th International Mine Water Association Congress – "Mine Water & Circular Economy – A Green Congress" (IMWA 2017), Rauha, Lappeenranta, Finland, June 25-30, 2017 (pp. 770-776). International Mine Water Association
Open this publication in new window or tab >>Understanding Groundwater composition at Kvarntorp, Sweden, from leaching tests and multivariate statistics
2017 (English)In: 13th International Mine Water Association Congress – Mine Water & Circular Economy: Proceedings, Volume 2 / [ed] Wolkersdorfer, C.; Sartz, L.; Sillanpää, M.; Häkkinen, A., International Mine Water Association , 2017, p. 770-776Conference paper, Oral presentation with published abstract (Other academic)
Abstract [en]

Due to oil production from alum shale, the Kvarntorp area is heavily polluted. A waste deposit consisting mostly of shale ash and fines is of important concern. Groundwater shows that parameters such as pH, U, V, Ni and Mo are different at different localities around the deposit. Leaching tests indicate that burned and unburned shale residues leave different signatures on leachates. Principal component analysis of groundwater and leaching tests suggest that ground-water is affected by the waste deposit and that it is more influenced by shale ash than by fines.

Place, publisher, year, edition, pages
International Mine Water Association, 2017
Series
Tutkimusraportit – Research Reports, ISSN 2243-3376 ; 3
Keywords
Alum shale, Kvarntorp, Shale oil, Leaching, Uranium
National Category
Environmental Sciences
Identifiers
urn:nbn:se:oru:diva-64732 (URN)978-952-335-065-6 (ISBN)978-952-335-066-3 (ISBN)
Conference
13th International Mine Water Association Congress – "Mine Water & Circular Economy – A Green Congress" (IMWA 2017), Rauha, Lappeenranta, Finland, June 25-30, 2017
Available from: 2018-01-31 Created: 2018-01-31 Last updated: 2019-03-26Bibliographically approved
Åhlgren, K., Sjöberg, V., Sartz, L. & Bäckström, M. (2017). Understanding Groundwater Composition at Kvarntorp, Sweden, from Leaching Tests and Multivariate Statistics. In: Wolkersdorfer, C., Sartz, L., Sillanpää, M. and Häkkinen, A (Ed.), Mine Water & Circular Economy: . Paper presented at IMWA 2017, Mine Water & Circular Economy, 13th International Mine Water Association Congress, Lappeenranta, Finland, 25-30 June, 2017 (pp. 770-776). Lappeenranta, Finland: Lappeenranta University of Technology, II
Open this publication in new window or tab >>Understanding Groundwater Composition at Kvarntorp, Sweden, from Leaching Tests and Multivariate Statistics
2017 (English)In: Mine Water & Circular Economy / [ed] Wolkersdorfer, C., Sartz, L., Sillanpää, M. and Häkkinen, A, Lappeenranta, Finland: Lappeenranta University of Technology , 2017, Vol. II, p. 770-776Conference paper, Published paper (Refereed)
Abstract [en]

Due to oil production from alum shale, the Kvarntorp area is heavily polluted. A waste deposit consisting mostly of shale ash and fines is of important concern. Groundwater shows that parameters such as pH, U, V, Ni and Mo are different at different localities around the deposit. Leaching tests indicate that burned and unburned shale residues leave different signatures on leachates. Principal component analysis of groundwater and leaching tests suggest that ground-water is affected by the waste deposit and that it is more influenced by shale ash than by fines.

Place, publisher, year, edition, pages
Lappeenranta, Finland: Lappeenranta University of Technology, 2017
Keywords
Alum shale, Kvarntorp, Shale oil, Leaching, Uranium
National Category
Geochemistry
Research subject
Chemistry
Identifiers
urn:nbn:se:oru:diva-71956 (URN)978-952-335-065-6 (ISBN)
Conference
IMWA 2017, Mine Water & Circular Economy, 13th International Mine Water Association Congress, Lappeenranta, Finland, 25-30 June, 2017
Available from: 2019-01-30 Created: 2019-01-30 Last updated: 2019-03-26Bibliographically approved
Åhlgren, K. & Bäckström, M. (2016). Identification of major point sources in the severely contaminated alum shale area in Kvarntorp, Sweden. In: Drebenstedt, C. & Paul, M. (Ed.), Mining Meets Water – Conflicts and Solutions: IMWA 2016 in Leipzig, Germany, July 11–15, 2016. Paper presented at Annual Meeting of the International-Mine-Water-Association (IMWA 2016), Leipzig, Germany, July 11-15, 2016 (pp. 377-382). Freiberg: TU Bergakademie Freiberg, Institute of Mining and Special Civil Engineering
Open this publication in new window or tab >>Identification of major point sources in the severely contaminated alum shale area in Kvarntorp, Sweden
2016 (English)In: Mining Meets Water – Conflicts and Solutions: IMWA 2016 in Leipzig, Germany, July 11–15, 2016 / [ed] Drebenstedt, C. & Paul, M., Freiberg: TU Bergakademie Freiberg, Institute of Mining and Special Civil Engineering , 2016, p. 377-382Conference paper, Published paper (Refereed)
Abstract [en]

Scarcity of imported fuel led to oil production from alum shale in the Kvarntorp area, 200 km west of Stockholm, during 1941-1966. Remains from this are a 100 meter high waste deposit, Kvarntorpshogen, consisting mostly of shale ash and water filled open pits. As this shale is rich in sulphur and trace metals such as U, Ni and Mo, leaching from the waste deposit is feared. To elucidate the important question whether Kvarntorpshgen is the most important concern, or to what extent other sources might contribute with contamination, water sampling was extended to contain more localities than the ordinary control program. A new approach was the sulphur isotope analysis. The results point towards an area too complex for using sulphur isotopes for mixing calculations. Isotope fractionation during oil production is shown by the delta(34) difference between shale and shale ash. Current isotope fractionation indicates sulphate reduction. Some localities indicate pyrite weathering and others rather show buffer capacities due to the presence of lime. Sr concentrations also suggest weathering. It is indicated that Kvarntorpshgen has an impact on the surroundings, but also that the water filled open pits as well as an industrial area affect the water quality. It is concluded that Kvarntorpshgen is one of the most important contributors of metal dispersion, but other point sources cannot be discarded as environmental risks.

Place, publisher, year, edition, pages
Freiberg: TU Bergakademie Freiberg, Institute of Mining and Special Civil Engineering, 2016
Keywords
Alum shale, Kvarntorp, Shale oil, Sulphur isotopes
National Category
Environmental Sciences
Research subject
Enviromental Science
Identifiers
urn:nbn:se:oru:diva-58801 (URN)000402663400060 ()978-3-86012-533-5 (ISBN)
Conference
Annual Meeting of the International-Mine-Water-Association (IMWA 2016), Leipzig, Germany, July 11-15, 2016
Available from: 2017-07-26 Created: 2017-07-26 Last updated: 2019-03-26Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-7680-1117

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