| 1. |
- Alakangas, Lena, et al.
(författare)
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Changes of groundwater quality in sulphide-bearing mine-tailings as a result of remediation at Kristineberg, northern Sweden
- 2007
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Ingår i: Mining and the Environment International Conference. - : Centre for Environmental Monitoring, Laurentian University. - 9780886670726
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Konferensbidrag (refereegranskat)abstract
- 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.
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| 2. |
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| 3. |
- Alakangas, Lena, et al.
(författare)
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Estimation of temporal changes in oxidation rates of sulphides in copper mine tailings at Laver, Northern Sweden
- 2010
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 408:6, s. 1386-1302
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 4. |
- Alakangas, Lena, et al.
(författare)
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Pilot-scale studies of different covers on unoxidised sulphide-rich tailings, northern Sweden : oxygen diffusion
- 2010
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Ingår i: Mine Water and the Environment. - Ostrava : VSB - Technical University Ostrava, Faculty of Mining and Geology, Institute of Environmental Engineering. - 9788024817675 ; , s. 347-350
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Konferensbidrag (refereegranskat)abstract
- 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.
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| 5. |
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| 6. |
- Kløve, Bjørn, et al.
(författare)
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Groundwater dependent ecosystems : Part I: Hydroecological status and trends
- 2011
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Ingår i: Environmental Science and Policy. - : Elsevier BV. - 1462-9011 .- 1873-6416. ; 14:7, s. 770-781
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Tidskriftsartikel (refereegranskat)abstract
- Groundwater dependent ecosystems (GDEs) include valuable ecosystems such as springs, wetlands, rivers, lakes and lagoons. The protection of these systems and services they provide is highlighted by international agreements, i.e. Ramsar convention on wetlands, and regional legislation, i.e. the European Water Framework Directive. Groundwater provides water, nutrients and a relatively stable temperature. However, the role of groundwater in surface ecosystems is not fully understood. The ecosystem can depend on groundwater directly or indirectly, and the reliance can be continuous, seasonal or occasional. This has implications for the vulnerability of ecosystems, as some may be easily affected by external pressure. Conceptual models and quantitative assessments of how groundwater interacts with the environment are needed. GDEs are also threatened by different land use activities and climate change. Hence, we need to understand how GDEs are affected by changes in groundwater quantity and quality, as severe groundwater changes have been observed in many regions. This study examines key aspects of GDEs (hydrogeology, geochemistry and biodiversity) in order to improve conceptual understanding of the role of groundwater in such ecosystems. The status and baseline of different types of GDEs are discussed, with particular emphasis on past evidence of environmental change and potential thresholds and threats in GDEs in various parts of Europe with different land use, climate and geology
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| 7. |
- Kløve, Bjørn, et al.
(författare)
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Groundwater dependent ecosystems. Part II. Ecosystem services and management in Europe under risk of climate change and land use intensification
- 2011
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Ingår i: Environmental Science and Policy. - : Elsevier BV. - 1462-9011 .- 1873-6416. ; 14:7, s. 782-793
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Tidskriftsartikel (refereegranskat)abstract
- Groundwater in sufficient amounts and of suitable quality is essential for potable water supplies, crop irrigation and healthy habitats for plant and animal biocenoses. The groundwater resource is currently under severe pressure from land use and pollution and there is evidence of dramatic changes in aquifer resources in Europe and elsewhere, despite numerous policy measures on sustainable use and protection of groundwater. Little is known about how such changes affect groundwater dependent ecosystems (GDEs), which include various aquatic and terrestrial ecosystems above ground and inside the aquifer. Future management must take this uncertainty into account. This paper focuses on multiple aspects of groundwater science, policy and sustainable management. Examples of current management methods and practices are presented for selected aquifers in Europe and an assessment is made of the effectiveness of existing policies such as the European Water Framework Directive and the Habitat Directive in practice and of how groundwaters and GDEs are managed in various conditions. The paper highlights a number of issues that should be considered in an integrated and holistic approach to future management of groundwater and its dependent ecosystems.
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| 8. |
- Kløve, Bjørn, et al.
(författare)
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Groundwater surface water interaction in GDE
- 2012
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Rapport (populärvet., debatt m.m.)abstract
- This report reviews and discussed the interaction of groundwaterin GDEs. The report presents and integrates past and new results.Different methods used to measure groundwater interaction withecosystems are presented. Various GENESIS case studies acrossEurope to demonstrate the variable and complex role ofgroundwater in GDEs. The basis for developing conceptual for GDEsis presented. Various methods to model GDEs are discussed.
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| 9. |
- Lundberg, Angela, et al.
(författare)
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Snow and frost : implications for spatiotemporal infiltration patterns - a review
- 2016
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Ingår i: Hydrological Processes. - : Wiley. - 0885-6087 .- 1099-1085. ; 30:8, s. 1230-1250
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Tidskriftsartikel (refereegranskat)abstract
- Vast regions of the northern hemisphere are exposed to snowfall and seasonal frost. This has large effects on spatiotemporal distribution of infiltration and groundwater recharge processes as well as on the fate of pollutants. Therefore, snow and frost need to be central inherent elements of risk assessment and management schemes. However, snow and frost are often neglected or treated summarily or in a simplistic way by groundwater modellers. Snow deposition is uneven, and the snow is likely to sublimate, be redistributed and partly melt during the winter influencing the mass and spatial distribution of snow storage available for infiltration, the presence of ice layers within and under the snowpack and, therefore, also the spatial distribution of depths and permeability of the soil frost. In steep terrain, snowmelt may travel downhill tens of metres in hours along snow layers. The permeability of frozen soil is mainly influenced by soil type, its water and organic matter content, and the timing of the first snow in relation to the timing of sub-zero temperatures. The aim with this paper is to review the literature on snow and frost processes, modelling approaches with the purpose to visualize and emphasize the need to include these processes when modelling, managing and predicting groundwater recharge for areas exposed to seasonal snow and frost
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| 10. |
- Lundberg, Angela, et al.
(författare)
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Spatiotemporal Variations in Snow and Soil Frost : A Review of Measurement Techniques
- 2016
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Ingår i: Hydrology. - : MDPI AG. - 2306-5338. ; 3:3
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Tidskriftsartikel (refereegranskat)abstract
- Large parts of the northern hemisphere are covered by snow and seasonal frost. Climate warming is affecting spatiotemporal variations of snow and frost, hence influencing snowmelt infiltration, aquifer recharge and river runoff patterns. Measurement difficulties have hampered progress in properly assessing how variations in snow and frost impact snowmelt infiltration. This has led to contradicting findings. Some studies indicate that groundwater recharge response is scale dependent. It is thus important to measure snow and soil frost properties with temporal and spatial scales appropriate to improve infiltration process knowledge. The main aim with this paper is therefore to review ground based methods to measure snow properties (depth, density, water equivalent, wetness, and layering) and soil frost properties (depth, water and ice content, permeability, and distance to groundwater) and to make recommendations for process studies aiming to improve knowledge regarding infiltration in regions with seasonal frost. Ground-based radar (GBR) comes in many different combinations and can, depending on design, be used to assess both spatial and temporal variations in snow and frost so combinations of GBR and tracer techniques can be recommended and new promising methods (auocostics and self potential) are evolving, but the study design must be adapted to the scales, the aims and the resources of the study. View Full-Text
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