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Åhlgren, K. & Bäckström, M. (2021). Environmental impact of alum shale mining and oil and uranium production in Kvarntorp, Sweden, based on historical archives and environmental monitoring data. Gorûcie slancy, 38(4), 338-359
Open this publication in new window or tab >>Environmental impact of alum shale mining and oil and uranium production in Kvarntorp, Sweden, based on historical archives and environmental monitoring data
2021 (English)In: Gorûcie slancy, ISSN 0208-189X, E-ISSN 1736-7492, Vol. 38, no 4, p. 338-359Article in journal (Refereed) Published
Abstract [en]

Oil production (1942-1966) and uranium extraction (1953-1961) from the Alum Shale Formation in Kvarntorp, Sweden has had a great environmental impact on the area. Other industrial activities have also contributed to pollution. This study combines archive research with monitoring data and new sampling in order to assess the extent of the impact. During the production period, process water containing oil, phenols, sulfur compounds and high concentrations of iron reached the stream resulting in low water quality downstream. Also the landscape was reshaped, resulting in water filled pit lakes and a 100-meter-high shale waste deposit. Today, past alum shale activities still have an impact on the environment. Sulfate concentrations in the pit lakes are significantly higher than background values and downstream water also shows higher concentrations of elements such as nickel and uranium. The waste deposit still has a hot interior and an important question is the cooling rate and possible future leaching scenarios. Remaining hydrocarbons show today only a local impact while trace elements are transported downstream and affect a larger area.

Place, publisher, year, edition, pages
Estonian Academy Publishers, 2021
Keywords
alum shale, black shale, uranium, Kvarntorp
National Category
Environmental Sciences
Identifiers
urn:nbn:se:oru:diva-95610 (URN)10.3176/oil.2021.4.04 (DOI)000720338500004 ()2-s2.0-85123032767 (Scopus ID)
Note

Funding agency:

Kumla municipality

Available from: 2021-11-29 Created: 2021-11-29 Last updated: 2023-12-08Bibliographically approved
Åhlgren, K., Sjöberg, V., Allard, B. & Bäckström, M. (2021). Groundwater chemistry affected by trace elements (As, Mo, Ni, U and V) from a burning alum shale waste deposit, Kvarntorp, Sweden. Environmental Science and Pollution Research, 28(23), 30219-30241
Open this publication in new window or tab >>Groundwater chemistry affected by trace elements (As, Mo, Ni, U and V) from a burning alum shale waste deposit, Kvarntorp, Sweden
2021 (English)In: Environmental Science and Pollution Research, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 28, no 23, p. 30219-30241Article in journal (Refereed) Published
Abstract [en]

Worldwide, black shales and shale waste are known to be a potential source of metals to the environment. This project demonstrates ongoing weathering and evaluates leaching processes at a 100-m-high shale waste deposit closed in the 1960s. Some deep parts of the deposit are still burning with temperatures exceeding 500 °C. To demonstrate ongoing weathering and leaching, analyses of groundwater and solid samples of shale and shale waste have been undertaken. Largest impact on groundwater quality was observed downstream the deposit, where elevated temperatures also indicate a direct impact from the burning waste deposit. Groundwater quality is largely controlled by pH and redox conditions (e.g., for arsenic, nickel, molybdenum, uranium and vanadium), and the mixture of different waste materials, including pyrite (acidic leachates) and carbonates (neutralizing and buffering pH). Analyses of shale waste from the deposit confirm the expected pyrite weathering with high concentrations of iron, nickel and uranium in the leachates. No general time trends could be distinguished for the groundwater quality from the monitoring in 2004-2019. This study has shown that black shale waste deposits can have a complex long-term impact on the surrounding environment.

Place, publisher, year, edition, pages
Springer, 2021
Keywords
Black shale, Groundwater chemistry, Trace elements
National Category
Environmental Sciences
Identifiers
urn:nbn:se:oru:diva-89618 (URN)10.1007/s11356-021-12784-2 (DOI)000617854700001 ()33586108 (PubMedID)2-s2.0-85101014604 (Scopus ID)
Note

Funding Agency:

Örebro University  

Available from: 2021-02-16 Created: 2021-02-16 Last updated: 2021-11-23Bibliographically approved
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, 39(3), 481-497
Open this publication in new window or tab >>Chemistry of Acidic and Neutralized Alum Shale Pit Lakes 50 Years After Mine Closure, Kvarntorp, Sweden
Show others...
2020 (English)In: Mine Water and the Environment, ISSN 1025-9112, E-ISSN 1616-1068, Vol. 39, no 3, p. 481-497Article in journal (Refereed) Published
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 ()2-s2.0-85080921121 (Scopus ID)
Note

Funding Agencies:

Örebro University  

SAKAB-Kumla Foundation  

Available from: 2020-03-20 Created: 2020-03-20 Last updated: 2020-12-16Bibliographically approved
Åhlgren, K. (2020). Environmental impact of alum shale mining in Kvarntorp, Närke, Sweden. (Doctoral dissertation). Örebro: Örebro University
Open this publication in new window or tab >>Environmental impact of alum shale mining in Kvarntorp, Närke, Sweden
2020 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Due to scarcity of imported liquid fuel during World War II, alum shale was mined for oil production in the Kvarntorp area 1942-1966. The shale contains both organic matter (kerogen) and elevated concentrations of trace elements such as molybdenum, nickel, uranium and vanadium. Today there are several pit lakes in the area and a 100-meter-high waste deposit, Kvarntorpshögen, consisting mostly of crushed and burned shale but also some unburned crushed shale and lime waste.

The aim of this study was to get a better understanding of the environmental impact of alum shale mining with focus on trace metal release. During the production era, the surroundings were highly affected by both sulphur rich flue gas emissions and bad water quality in downstream waters. The former mining activities show impact also today, with higher concentrations in downstream water than upstream the area. Analyses and leaching tests of solid samples have shown pyrite weathering in shale and unburned shale waste with release of for example nickel and uranium.

Analyses of groundwater in eleven wells around the deposit show ongoing leaching of both shale waste generating a circumneutral leachate and unprocessed shale leading to acidic leachates.

All pit lakes in contact with alum shale waste or the shale horizon show elevated sulphate concentrations indicating pyrite weathering, although only one is still acidic today. Also Norrtorpssjön was acidic until a pH rise due to adjacent dumping of alkaline waste. The pH increase was followed by a decrease in aluminium, cobalt, magnesium and nickel.

Surface water analysis show that the waste deposit is estimated to contribute with less than a fifth of the mass transport whereas the western pit lakes contribute with the largest part.

Place, publisher, year, edition, pages
Örebro: Örebro University, 2020. p. 80
Series
Örebro Studies in Chemistry, ISSN 1651-4270 ; 27
Keywords
alum shale, black shale, oil shale, Kvarntorp, uranium, surface water, groundwater, open pits
National Category
Other Chemistry Topics
Identifiers
urn:nbn:se:oru:diva-87667 (URN)978-91-7529-362-2 (ISBN)
Public defence
2021-01-08, Örebro universitet, Forumhuset, Hörsal F, Fakultetsgatan 1, Örebro, 09:15 (English)
Opponent
Supervisors
Available from: 2020-11-27 Created: 2020-11-27 Last updated: 2020-12-18Bibliographically approved
Åhlgren, K., Sjöberg, V. & Bäckström, M. (2020). Estimating Release of Trace Elements from an Area with Historical Open Pit Mining of Alum Shale Using Mass Transport and Element/Sulfate Ratios Calculations. Environments, 7(11), Article ID 100.
Open this publication in new window or tab >>Estimating Release of Trace Elements from an Area with Historical Open Pit Mining of Alum Shale Using Mass Transport and Element/Sulfate Ratios Calculations
2020 (English)In: Environments, E-ISSN 2076-3298, Vol. 7, no 11, article id 100Article in journal (Refereed) Published
Abstract [en]

Alum shale was mined for oil and uranium production in Kvarntorp, Sweden, 1942-1966. Remnants such as pit lakes, exposed shale and a 100-meter-high waste deposit with a hot interior affect the surrounding environment, with elevated concentrations of, e.g., Mo, Ni and U in the recipient. Today most pit lakes are circumneutral while one of the lakes is still acidic. All pit lakes show signs of sulfide weathering with elevated sulfate concentrations. Mass transport calculations show that for elements such as uranium and molybdenum the western lake system (lake Soderhavet in particular) contributes the largest part. For sulfate, the two western lakes contribute with a quarter each, the eastern lake Norrtorpssjon about a third and a serpentine pond system receiving water from the waste deposit contributes around 17%. Except for a few elements (e.g., nickel 35%), the Serpentine system (including the waste deposit area) is not a very pronounced point source for metal release compared to the pit lakes. Estimates about future water runoff when the deposit has cooled down suggest only a slight increase in downstream water flow. There could possibly be first flush effects when previous hot areas have been reached by water.

Place, publisher, year, edition, pages
MDPI, 2020
Keywords
alum shale, black shale, Kvarntorp, trace elements, sulfate, weathering, uranium
National Category
Environmental Sciences
Identifiers
urn:nbn:se:oru:diva-88063 (URN)10.3390/environments7110100 (DOI)000592812100001 ()2-s2.0-85097077569 (Scopus ID)
Available from: 2020-12-15 Created: 2020-12-15 Last updated: 2023-02-20Bibliographically 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
Åhlgren, K. & Bäckström, M.Environmental impact from alum shale mining, oil and uranium production in Kvarntorp, Sweden, based on historical archives and environmental monitoring data.
Open this publication in new window or tab >>Environmental impact from alum shale mining, oil and uranium production in Kvarntorp, Sweden, based on historical archives and environmental monitoring data
(English)Manuscript (preprint) (Other academic)
National Category
Other Chemistry Topics
Identifiers
urn:nbn:se:oru:diva-88101 (URN)
Available from: 2020-12-16 Created: 2020-12-16 Last updated: 2020-12-16Bibliographically approved
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Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-7680-1117

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