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| 2. |
- Elgh-Dalgren, Kristin, et al.
(författare)
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Anaerobic bioremediation of a soil with mixed contaminants : Explosives degradation and influence on heavy metal distribution, monitored as changes in concentration and toxicity
- 2009
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Ingår i: Water, Air and Soil Pollution. - Dordrecht : Springer Netherlands. - 0049-6979 .- 1573-2932. ; 202:1-4, s. 301-313
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Tidskriftsartikel (refereegranskat)abstract
- Two soils with explosives and metals were evaluated for the degradation efficiency of explosives by native microorganisms under anaerobic conditions. The commercially available method Daramend®, amended with zero-valent iron (ZVI), was compared with a horse-manure amended compost and a treatment with ZVI alone. In a moderately contaminated soil, Daramend® and ZVI treatment gave significantly higher removal rates compared to compost and control treatments (Tukey’s test, P<0.05). The largest overall decrease in ecotoxicity, measured with bioluminescent bacteria (Vibrio fischeri), was achieved with ZVI-treatment. In a more contaminated soil no degradation of contaminants and no decline in soil toxicity could be distinguished after the same time period. Problems with establishment of anaerobic conditions during parts of the remediation process and low microbial activity due to acute toxicity of contaminants are plausible explanations. Redistribution that could potentially lead to mobilization of the co-contaminant Pb was not observed in either of the soils during the biological treatments.
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| 3. |
- Grahn, Evastina, et al.
(författare)
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Historical pollution of seldom monitored trace elements in Sweden : Part B: sediment analysis of silver, antimony, thallium and indium
- 2006
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Ingår i: Journal of Environmental Monitoring. - 1464-0325 .- 1464-0333. ; 8:7, s. 732-744
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Tidskriftsartikel (refereegranskat)abstract
- Sediment cores from four boreal and remote lakes in a south to north transect in central Sweden were analysed for acid leachable silver, antimony, thallium and indium in the solid sediment phase and the corresponding porewater. Dating of the cores was made by their content of acid leachable lead and the 206Pb/207Pb ratio, in one lake also by 210Pb. The impact of diagenesis on element redistribution in the sediments was included and found to be minor except for thallium. The results show lowered concentrations towards the north and most intense accumulation after the Second World War, which is taken as evidence for atmospheric deposition being the primary source. Indium has declining concentrations in recent strata while silver and antimony increase. Thallium has lowered acid-leachable concentrations in recent strata. For all metals the impact of domestic industrialisation as well as the early industrialisation of central Europe is discernible. Only thallium appears to reach a geological background at depths that correspond to the late 18th century. For the other metals elevated levels are concluded.
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| 4. |
- Grahn, Evastina, 1968-
(författare)
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Lake sediment as environmental archive : natural and anthropogenic influence on the chronology of trace elements
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The focus of this thesis is the historical pollution of some seldom-monitored trace elements (SMTEs; Ag, Be, Ga, In, Sb and Tl) that have been involuntarily released for several thousands of years but whose usage have increased during the industrial era. Sediment cores from four rural lakes in a south to north transect in central Sweden, and two urban lakes have been used as environmental archives for chronological studies. The historical development of the SMTEs is put in perspective of frequently monitored elements (Cd, Cu, Pb and Zn) that serve as a well-known anthropogenic signal. Dating of the sediments is made with 210Pb, 137Cs and 239,240Pu as well as acid leachable lead and the 206Pb/207Pb ratio. The impact of diagenetic redistribution is included, when necessary. The results show that site-specific reference concentrations are required in order to estimate the present pollution as well as its historical development. Atmospheric deposition is the principal pathway of transport in rural lakes and the concentrations are lowered towards the north. It is not possible from this material, however, to separate the direct deposition on the lake surfaces from the contribution from their catchments. From 21Pb, acid-leachable Pb and the 206Pb/207Pb ratio a minimum of four periods of pollution can be discerned. For the SMTEs the quantitatively most important period of pollution took place from the Second World War until present. The growth of the domestic industrialisation as well as the early industrialisation of central Europe and the British Isles are also distinguishable. The pollution history of Ag, In and Sb goes back for several centuries as a result of metal processing whereas the levels of thallium mainly increase as a result of industrialisation. For Ag and Tl in-sediment diagenetic redistribution limits the precision of the historical estimate. The preliminary interpretation of 137Cs and 239,240Pu indicates that they are less suitable as chronological markers in the system studied. The urban impact on the trace metal sediment content in the urban lakes was lower than expected, except for Au. There is a large impact from hydrological conditions on the studied system why further investigations are recommended.
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| 5. |
- Grahn, Evastina, et al.
(författare)
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Sediment reference concentrations of seldom monitored trace elements (Ag, Be, In, Ga, Sb, Tl) in four Swedish boreal lakes : comparison with commonly monitored elements
- 2006
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 367:2-3, s. 778-790
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents reference and recent acid-leachable concentrations of some seldom monitored trace elements (SMTE; Ag, Be, Ga, In, Sb and Tl) in sediments from four boreal oligotrophic lakes in a south to north transect in Sweden. For comparison commonly monitored trace elements (As, Cd, Co, Cr, Cu, Ni, Pb and Zn) are included as well as those of relevance for redistribution processes (Al, Ca, Fe, Mg and Mn). Pore water pH and the corresponding solid/solution distribution coefficients (Kd) indicated that redistribution of the elements due to acidification is minor. The depth of impact was defined as the level in the sediment where the mean values became constant on successive exclusion of metal concentrations in overlying strata. Reference concentrations were calculated below the depth of impact. The present concentration changes are estimated by the ratio between the average concentration above the depth of impact and the reference concentration. Reference concentration ranges for the SMT-elements are (mg/kg, dry wt.): Ag 0.16–0.66; Be 1.6–3.7; Ga 2.0–5.1; In 0.05–0.22; Sb 0.05–0.11 and Tl 0.17–0.70. The concentration ratios for these elements ranged in the two most southern lakes from 1.5 to 4.5 and in the two northern ones from 0.6 to 1.6. A high correlation between Kd for the SMT-elements, and iron, except for Sb and Tl, infer that the biogeochemistry of iron is quantitatively important for the accumulation of these elements. The reference concentration ranges for the commonly monitored trace elements are (mg/kg, dry wt.): As 7.0–29.6; Cd 0.33–0.98; Co 5.7–23.8; Cr 15.2–26.1; Cu 27.6–58.4; Ni 5.4–20.8; Pb 44–96. The corresponding concentration ratios were 1.2–18 (second highest 3.9) in the two most southern lakes and 0.8–1.6 in the two northern ones. Declining ratios were found from south to north, most obvious for cobalt and zinc. The copper ratios did not show a regional pattern, partly because of the impact from old mine waste. Increased concentrations of Ag, Be, Ga, In, Sb and Tl in recent sediments up to 4.5 times the reference levels in combination with the geographical pattern infer an elevated loading of these elements.
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| 6. |
- Greis, Christina, 1975-, et al.
(författare)
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Determination of plutonium in environmental samples with quadrupole ICP-MS
- 2008
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Ingår i: Journal of Radioanalytical and Nuclear Chemistry. - Berlin : Springer. - 0236-5731 .- 1588-2780. ; 275:1, s. 55-70
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Tidskriftsartikel (refereegranskat)abstract
- A method for rapid determination of plutonium isotopes in environmental samples with ultrasonic nebulisation and quadrupole ICP-MS detection was established. Techniques for sample dissolution, pre-concentration and chemical separation were evaluated and the optimal scheme outlined. Comparisons with α-spectrometry and high resolution ICP-MS confirmed the suitability of the method when applied to different environmental matrices within the global fallout concentration range in the northern hemisphere as well as more contaminated sites. Operational detection limits were 0.5–1.5 fg/l for fresh waters and 0.03–0.1 ng/kg for lake sediments and saline marsh sediments.
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| 7. |
- Greis, Christina, 1975-, et al.
(författare)
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Plutonium remobilization in a humic-rich lake
- 2007
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Ingår i: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 277:1, s. 265-268
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Tidskriftsartikel (refereegranskat)abstract
- Fresh water from Lake Svartsjön, Sweden, was collected and four fractions were prepared: (1) adsorption on DEAE, (2) flocculation with Ca2+, (3) co-precipitation with Fe hydrous oxide and (4) co-precipitation with Mn hydrous oxide. The plutonium level in the lake is 65 fg/l (222 μBq/l), measured by ICP-QMS and ICP-SFMS. Pronounced accumulation in fractions (1) (34%) and (2) (66%), combined with observed levels of organic matter indicate that plutonium is predominantly associated with organic matter. Measurements of isotopic ratios indicate that 77% of the plutonium originates from weapons testing and the remaining appears to originate from the Chernobyl accident.
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| 8. |
- Greis, Christina, 1975-
(författare)
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Rapid analysis of actinide isotopes using quadrupole ICP-MS for emergency preparedness and environmental monitoring
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Transuranium elements in the environment are mainly derived from nuclear weapons testing and the nuclear fuel cycle. Of growing concern are illicit nuclear trafficking and the threat of terror acts. The development of rational methods, for environmental monitoring and for tracing sources of nuclear and radioactive materials in the environment, is constantly required. Traditionally, the actinides have been determined by radiometric techniques. These analyses can be time consuming for elements at low concentrations and with long half-lives. This thesis addresses the determination of actinides, especially plutonium, in environmental samples with ICP-QMS (inductively coupled plasma quadrupole mass spectrometry). The ICP-QMS instrument was equipped with an USN (ultrasonic nebuliser), which proved to be a successful combination for the determination of plutonium at low concentrations in acidified solutions after separation with anion exchange. The detection limit for plutonium was in the range 10-30 pg/l with a RSD of 1-10%. The suitability of chemical separation was evaluated for anion exchange, liquid-liquid-extraction and extraction chromatography. The outlined procedure, including sample dissolution, chemical separation and analysis, for determination of actinides in environmental matrices proved to be accurate and reliable. Quality assurance of the procedure was performed during an intercomparison exercise and with reference materials. The detection accuracy has also been validated with α-spectrometry and ICP-SFMS. The procedure has been applied to saline sediments and fresh water sediments as well as several fresh water matrices.
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| 9. |
- Karlsson, Stefan, et al.
(författare)
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Historical pollution of seldom monitored trace elements in Sweden - Part A : sediment properties and chronological indicators
- 2006
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Ingår i: Journal of Environmental Monitoring. - 1464-0325 .- 1464-0333. ; 8:7, s. 721-731
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Tidskriftsartikel (refereegranskat)abstract
- Sediment cores from four small oligotrophic boreal lakes, with minor acidification, in remote regions of central Sweden were used for historical interpretation of their metal content, with focus on Cu, Cd, Pb and Zn in Lake Stensjön, which has the longest sediment record (at least two centuries according to 210Pb dating). Comparison is made with the other three lakes. Major and trace elements in lake water, porewater and the acid-leached (HNO3) solid sediment phase was analysed with ICP-MS. In addition, general lake water chemistry, TOC and principal anions were measured in the aqueous phases. Redistribution processes were interpreted from geochemical modelling. The solid/solution distribution of pe/pH sensitive elements, indicates a minor diagenetic redistribution and the concentration profiles are therefore suitable for chronological evaluation. The ratios of Al, Ti, Sc and V, indicated a qualitative shift of sedimenting material a century ago, which did not have any impact on the retention of trace elements. Lead had a concentration profile, supported by the 206Pb/207Pb ratio, where it was possible to distinguish preindustrial conditions, early industrialisation in Europe, industrialisation in Sweden, and the use of leaded petrol after the Second World War. Cadmium showed a similar concentration pattern. The zinc profile resembled that of cadmium, but with less enrichment. Local lithogenic sources are believed to be quantitatively important. The solid/solution distribution (Kd) was independent of depth for all four elements. The sediment concentrations of copper and zinc are not related to early industrialisation but its concentration has doubled since the Second World War.
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| 10. |
- Karlsson, Stefan, et al.
(författare)
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Sediment chronologies of As, Bi, and Ga in Sweden - impact of industrialisation
- 2007
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Ingår i: Journal of Environmental Science and Health. Part A. - : Informa UK Limited. - 1093-4529 .- 1532-4117. ; 42:2, s. 155-164
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Tidskriftsartikel (refereegranskat)abstract
- The acid-leachable amount and pore water concentration of As, Bi and Ga in sediment cores from four remote lakes in a south to north transect in Sweden were used to recapitulate the pollution history of the elements. The diagenetic impact on the element distribution was elucidated from their solid/solution partition and relationships to elements indicative for diagenesis. Dating was made by their acid-leachable lead content in combination with the Pb-206/Pb-207 ratio. In one of the lakes this approach was validated against dating with Pb-210. The impact of diagenesis on the sediment distribution of theses elements was found to be low enough for a chronological interpretation of the sediment profiles, as evidenced by their ratios to elements indicative of the geological background. A closer examination of the diagenetic impact would however be required if a more detailed chronology is desired. This study has demonstrated that atmospheric deposition of arsenic, bismuth and gallium contributes to the sediment inventory of these elements. The major part of the deposition of arsenic and bismuth took place after the Second World War. For gallium no concentrations exceeding background were detected before circa 1930. Increased levels of arsenic are traceable to circa 1850. For bismuth increased levels are concluded to extend before 1790, i.e., background concentrations were not reached in the present cores. For all elements the atmospheric deposition has been lower towards the north.
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