| 1. |
- Bucksch, S., et al.
(author)
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The Swedish program for investigations concerning biofuels
- 1999
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In: Science of the Total Environment. - 0048-9697 .- 1879-1026. ; 235:1-3, s. 293-303
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Journal article (peer-reviewed)abstract
- As constituted today, the transport sector is not sustainable in the long-term. It is based almost entirely on non-replenishable natural resources which, when combusted, release emissions that can cause serious harm to human beings, animals and the natural environment. Therefore, in order to achieve a sustainable transport system, it is imperative to achieve a means of propulsion, which is based on renewable energy sources in every phase of production and distribution. The responsibility for developing such a sustainable transport system is an assignment, which must be approached as a common cause, involving both the official agencies of society and the business sector together with international cooperation. In 1991 the Swedish Government allocated 120 million Swedish crowns to the Swedish Transport and Communications Research Board (KFB) as funds for research, development and demonstration in the field of biofuels to be used in the transportation sector. In order to fulfil this obligation a program was presented and approved and this program for engine alcohols and biogas was carried out between the summer of 1991 and the end of 1997. The program has generated a broad spectrum of useful results showing that, in general terms, there are a number of technical problems connected to the use of biofuels. There is also a need to continue the development of both the fuels and the engines in order to take advantage of all that can be achieved concerning the use of biofuels in the transportation sector. The presentation at The Sixth International Highway and Urban Pollution Symposium will focus on a brief description of the program carried out and a presentation of the results of the field tests and the emission characterisation.
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| 2. |
- Carlsson, E., et al.
(author)
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Sequential extraction of sulfide-rich tailings remediated by the application of till cover, Kristineberg mine, northern Sweden
- 2002
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In: Science of the Total Environment. - 0048-9697 .- 1879-1026. ; 299:1-3, s. 207-226
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Journal article (peer-reviewed)abstract
- 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. © 2002 Elsevier Science B.V. All rights reserved.
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| 3. |
- Holmström, Henning, et al.
(author)
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Geochemical investigations of sulfide-bearing tailings at Kristineberg, northern Sweden, a few years after remediation
- 2001
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In: Science of the Total Environment. - 0048-9697 .- 1879-1026. ; 273:1-3, s. 111-113
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Journal article (peer-reviewed)abstract
- 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.
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| 4. |
- Holmström, Henning, et al.
(author)
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The character of the suspended and dissolved phases in the water cover of the flooded mine tailings at Stekenjokk, northern Sweden
- 2000
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In: Science of the Total Environment. - 0048-9697 .- 1879-1026. ; 247:1, s. 15-31
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Journal article (peer-reviewed)abstract
- 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.
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| 5. |
- Lindgren, Åsa
(author)
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Asphalt wear and pollution transport
- 1996
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In: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 189-190, s. 281-286
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Journal article (peer-reviewed)abstract
- Studded tires cause extensive wear of road surfaces during winter producing small particles. Besides transporting different adsorbed pollutants these particles also discharge metal ions by their own natural content. The major part (95%) of the asphalt is composed of stone fractions. The rest consists mainly of bitumen, which contains trace quantities of metals. Laboratory studies in this study have demonstrated different adsorbing properties of metal ions, as well as differences in adsorption when comparing stone materials. Two stone materials, a gabbro and a porphyry, have been tested for their adsorption properties concerning Pb, Cu, Zn and Cd. The gabbro showed better adsorption capacity than the porphyry. Gabbro has coarser grains, it is softer, and also has a higher content of most metals compared to the porphyry. In all tests lead and copper are more adsorbed than zinc and cadmium. All metal ions are released at about the same pH ({approx}4)
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| 6. |
- Müller, Barbara, et al.
(author)
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Adsorption of trace elements on pyrite surfaces in sulfidic mine tailings from Kristineberg (Sweden) : a few years after remediation
- 2002
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In: Science of the Total Environment. - 0048-9697 .- 1879-1026. ; 298:1-3, s. 1-16
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Journal article (peer-reviewed)abstract
- Laser ablation inductively coupled plasma mass spectrometry (LA ICP-MS) has been used to determine the elemental composition of the surface and interior layers of pyrite grains from the mine tailings from Kristineberg (northern Sweden) in order to determine concentration gradients between these two layers. The pyrite grains were collected from oxidized and unoxidized zones within the tailings. The aim of this study was to assess the role of pyrite surfaces as sites for the attenuation of solutes from the mine-tailings porewater. The normalized intensities of Cu, Zn, Ag, Sb, Ce, Pb and Bi are highest at the surface of each grain (within the surface layer drilled by the LA) and decrease towards the interior. The surface adsorption of Cu, Zn and Pb is more pronounced within the unoxidized than within the oxidized zone of the tailings. Copper exhibits a distinct concentration peak at the surface of the pyrite grains below the pre-remediation oxidation front. Silver, Sb, Bi, As and Au are preferably adsorbed within the uppermost layer of the oxidized zone in the tailings, where the pH is as high as 6.2. The conversion of intensity signals of the elements to concentration values in ppm was accomplished using an external calibration against an in-house pyrite standard.
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| 7. |
- Rodushkin, Ilia, et al.
(author)
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Application of double focusing sector field ICP-MS for multielemental characterization of human hair and nails : Part I: Analytical methodology
- 2000
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In: Science of the Total Environment. - 0048-9697 .- 1879-1026. ; 250:1-3, s. 83-100
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Journal article (peer-reviewed)abstract
- The capabilities of double focusing sector field inductively coupled plasma mass spectrometry (ICP-SMS) for the determination of 71 elements in hair and nails were studied. A microwave-assisted digestion procedure with nitric acid and hydrogen peroxide as well as direct sampling of the nails by laser ablation (LA) have been tested. Examples of spectral interferences are given and different correction procedures are discussed. Method detection limits below ng g-1 were obtained for 39 elements investigated by using high-purity reagents and by taking special care to prevent contamination during preparation. However, these detection limits were insufficient for detection of some platinum group elements in the majority of the samples. The accuracy of the analytical procedure was estimated by analysis of the GBW07601 certified reference material as well as by participation in an interlaboratory comparison program. The reproducibility was assessed from replicate analysis (including sample preparation) and was found to be, as average values for all elements, 9-10% R.S.D. and 18-19% R.S.D. for hair and nails, respectively. Contribution from exogenous deposition was evaluated by analyzing samples before and after washing, as well as by studying spatial element distribution along hair and nails. It was found that even after sample washing, many elements are enriched in the surface of the nail.
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| 8. |
- Rodushkin, Ilia, et al.
(author)
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Application of double focusing sector field ICP-MS for multielemental characterization of human hair and nails : Part II: A study of the inhabitants of northern Sweden
- 2000
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In: Science of the Total Environment. - 0048-9697 .- 1879-1026. ; 262:1-2, s. 21-36
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Journal article (peer-reviewed)abstract
- Double-focusing sector-field, inductively coupled plasma-mass spectrometry was used for the determination of 71 elements in scalp hair and fingernail samples from an urban population group living in the north-east of Sweden. Samples (n=114 for hair and n=96 for nails) were taken from subjects without known occupational exposure to metals. From these results, concentration ranges were calculated and compared with published intervals. Statistical analysis was used to elucidate differences according to sex, age and smoking habit. It was found that significant correlations exist between different elements in hair and nails, as well as between hair and nail concentrations for several elements. Strong positive correlation for Hg, Cd, Pb, Sb and Bi levels between these media confirms that both can be used for exposure assessment for these elements. Several examples on the use of distribution patterns for the rare-earth elements (REE) and of Pb isotope ratios for assessment of exposure are given.
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| 9. |
- Rodushkin, Ilia, et al.
(author)
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Application of double focusing sector field ICP-MS for multielemental characterization of human hair and nails : Part III: Direct analysis by laser ablation
- 2003
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In: Science of the Total Environment. - 0048-9697 .- 1879-1026. ; 305:1-3, s. 23-39
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Journal article (peer-reviewed)abstract
- The capabilities of laser ablation double focusing sector field inductively coupled plasma mass spectrometry for the determination of 55 elements in nails and hair were studied. Quantification was performed by external calibration using in-house matrix-matched standards in tablet form following correction for variations in ablation efficiency by internal standardization using a matrix element (S). For nails, intra-individual long- and short-term chronological variations as well as depth distribution patterns were studied. For the majority of elements tested, significant enrichment was found in the surface of the nail. Element distributions along a hair strand were investigated with a spatial resolution of 2.5 mm.
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| 10. |
- Rodushkin, Ilia, et al.
(author)
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Multi-element analysis of wild berries from northern Sweden by ICP techniques
- 1999
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In: Science of the Total Environment. - 0048-9697 .- 1879-1026. ; 231:1, s. 53-65
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Journal article (peer-reviewed)abstract
- In this study, the abundances of 60 chemical elements were determined in berries of blueberry (Vaccinium myrtillus) and lingonberry (Vaccinium vitis-idaea) by a combination of inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma double focusing sector field mass spectrometry (ICP-SMS). Samples of both species were collected at 35 sites in northern Sweden. The sites are related to four zones representing areas affected by different types of human activity as well as an adjacent reference area. Special care was taken to keep sample contamination during sampling and sample preparation as low as possible. Different approaches such as use of an internal quality control sample, spike recovery tests and comparison between different analytical techniques, were used to ensure the quality of the results. Variations in element concentrations within individual sampling sites were estimated, based upon in-site duplicate sampling and analysis. The contribution from surface contamination to total berry concentrations was assessed by analysis of samples before and after rinsing with water. A comparison of the two species showed that, in spite of very similar concentrations for the majority of the elements, the highest Tl, Sr and Ba values were found in lingonberry while the highest Cl and Re concentrations were found in blueberry. The highest total concentrations of Ag, As, Be, Bi, Br, Cd, Hg, I, Ni, Pb, Sb and Tl were found in berries from mining areas, whereas those of Li, V, Hf, W, Ta and REE were found in the vicinity of high-traffic roads.
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