| 1. |
- Jonsson, Sofia, 1973-, et al.
(författare)
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Degradation of polycyclic aromatic hydrocarbons (PAHs) in contaminated soils by Fenton's reagent : a multivariate evaluation of the importance of soil characteristics and PAH properties
- 2007
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Ingår i: Journal of Hazardous Materials. - : Elsevier BV. - 0304-3894 .- 1873-3336. ; 149:1, s. 86-96
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we investigated how the chemical degradability of polycyclic aromatic hydrocarbons (PAHs) in aged soil samples from various contaminated sites is influenced by soil characteristics and by PAH physico-chemical properties. The results were evaluated using the multivariate statistical tool, partial least squares projections to latent structures (PLS). The PAH-contaminated soil samples were characterised (by pH, conductivity, organic matter content, oxide content, particle size, specific surface area, and the time elapsed since the contamination events, i.e. age), and subjected to relatively mild, slurry-phase Fenton's reaction conditions. In general, low molecular weight PAHs were degraded to a greater extent than large, highly hydrophobic variants. Anthracene, benzo(a)pyrene, and pyrene were more susceptible to degradation than other, structurally similar, PAHs; an effect attributed to the known susceptibility of these compounds to reactions with hydroxyl radicals. The presence of organic matter and the specific surface area of the soil were clearly negatively correlated with the degradation of bi- and tri-cyclic PAHs, whereas the amount of degraded organic matter correlated positively with the degradation of PAHs with five or six fused rings. This was explained by enhanced availability of the larger PAHs, which were released from the organic matter as it degraded. Our study shows that sorption of PAHs is influenced by a combination of soil characteristics and physico-chemical properties of individual PAHs. Multivariate statistical tools have great potential for assessing the relative importance of these parameters.
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| 2. |
- Andersson, Agneta, et al.
(författare)
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Projected future climate change and Baltic Sea ecosystem management
- 2015
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Ingår i: Ambio. - : Springer. - 0044-7447 .- 1654-7209. ; 44:Supplement 3, s. S345-S356
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Tidskriftsartikel (refereegranskat)abstract
- Climate change is likely to have large effects on the Baltic Sea ecosystem. Simulations indicate 2-4 degrees C warming and 50-80 % decrease in ice cover by 2100. Precipitation may increase similar to 30 % in the north, causing increased land runoff of allochthonous organic matter (AOM) and organic pollutants and decreased salinity. Coupled physical-biogeochemical models indicate that, in the south, bottom-water anoxia may spread, reducing cod recruitment and increasing sediment phosphorus release, thus promoting cyanobacterial blooms. In the north, heterotrophic bacteria will be favored by AOM, while phytoplankton production may be reduced. Extra trophic levels in the food web may increase energy losses and consequently reduce fish production. Future management of the Baltic Sea must consider the effects of climate change on the ecosystem dynamics and functions, as well as the effects of anthropogenic nutrient and pollutant load. Monitoring should have a holistic approach, encompassing both autotrophic (phytoplankton) and heterotrophic (e.g., bacterial) processes.
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| 3. |
- Miller, Aroha, et al.
(författare)
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Comparing temporal trends of organochlorines in guil-lemot eggs and Baltic herring : Advantages and disadvantages for se-lecting sentinel species for environmental monitoring
- 2014
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Ingår i: Marine Environmental Research. - : Elsevier BV. - 0141-1136 .- 1879-0291. ; 100, s. 38-47
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Tidskriftsartikel (refereegranskat)abstract
- Within Europe, the Marine Strategy Framework Directive (MSFD) is aimed at addressing the chemical status and quality of the marine environment. One of the main goals is to achieve Good Environmental Status (GES) in the marine environment. Environmental monitoring of biota e.g., Baltic herring and guillemot eggs, is conducted annually in Sweden to follow temporal changes in environmental contaminants. To determine the suitability of guillemot eggs as a sentinel species for investigating GES, we compared temporal trends of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in these two species from single sampling sites within Sweden.Lipid content from guillemot eggs was consistently high and stable (yearly mean for >40 years, ∼12%) compared to that of herring (yearly mean for >20 years, ∼3%). A significant decreasing trend of ΣPCDD/F in TEQ WHO1998 was observed in guillemot eggs, but no trend was seen in herring. CB118 significantly decreased in both species, but in the last 10 years this decrease was not significant in herring. A number of advantages, such as high lipid content in the egg and a low coefficient of variation make guillemot suitable as a sentinel species. The advantages and disadvantages of using either guillemot eggs or Baltic herring are compared.
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| 4. |
- Olofsson, Ulrika, 1967-
(författare)
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Removal processes in sewage treatment plants : Sludge quality and treatment efficiency of structurally diverse organic compounds
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Large and ever-increasing numbers of chemicals, including large quantities of a broad spectrum of organic compounds are used in modern society. More than 30 000 of the more than 100 000 chemical substances registered in the EU are estimated to be daily used, of which many will be discharged into the waste-streams handled by municipal sewage treatment plants (STPs). The main objective of the work underlying this thesis was to improve understanding of the relationships between the characteristics of sewage contaminants and their sewage treatment efficiency. Further objectives were to examine the relationships between socio-economic uses of chemicals and sludge quality, and the effects of regulatory actions on sludge quality. The quality of the sewage sludge and the levels and distribution patterns of the sludge contaminants, both within and between the STPs, seem to remain quite constant over time. The overall findings indicate that the levels of contaminants in sewage sludge seem to be largely independent of the location, size and treatment techniques applied at the STPs, and generally, of the types of human activity connected to them. The total and relative concentrations of the sludge contaminants were found to be fairly constant on a dry weight basis, with some exceptions, indicating that the pollutants originate from broad usage and diffuse dispersion rather than (industrial) point sources. The proportion of cyclic methylsiloxanes recovered in sludge seems to strongly depend on their vapour pressure, which decreases with the number of siloxane units. The higher water solubility and biodegradability of organophosphorus flame retardants and plasticizers than polybrominated diphenyl ethers (PBDEs) were also reflected in lower percentages (relative to their national use) found in sludge. Significant time-trends in levels of a-third of the sludge contaminants included in the annual national measurement program were detected over a period of seven years. The levels of compounds displaying significant time-trends generally decreased following declines in the quantities used nationally. However, a quarter of these compounds showed increasing trends, of which the linear methylsiloxanes followed the same trend as used quantities. The decaBDE was also found to be increasing in sludge, probably as a result of the phase-out of pentaBDE and octaBDE. The results indicate that the STP removal efficiency of anthropogenic substances, in Sweden, is generally good and that STPs, at least those in cold climates, do not efficiently remove certain polar contaminants. A non-targeted screening (by use of environmetrics and GCxGC-TOFMS) was performed and found to fulfil the objective to assess the STP removal efficiency, with emphasis to systematically analyse which compound classes that are not efficiently removed using the current STP technology. Many polar aromatic compounds were identified to be poorly removed. The acquired data on levels, profiles and variations in sludge contaminants (sludge quality) extend both the available information and understanding of the degree and nature of sludge contamination, which should help attempts to track changes in its contaminants and revisions, if necessary, of guideline values. This thesis also contributes to improve the knowledge base for the development of future STP technologies, and that archived sewage sludge can be used in retrospective analysis of new and emerging pollutants.
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| 5. |
- Wingfors, Håkan, 1970-
(författare)
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Pollutant profiles as tools for characterisation of environmental exposure
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis is concerned with measurements of persistent organic pollutants (POPs) in environmental samples. The POPs consist of several groups of compound with many isomers, hence analysing POPs in a complex environment is a This thesis is concerned with measurements of persistent organic pollutants (POPs) in environmental samples. The POPs consist of several groups of compound with many isomers, hence analysing POPs in a complex environment is a challenging task. Studies of the abundance or dynamics of such substances in the environment require careful consideration of several key steps. The environmental and analytical problems must be correctly defined, suitable analytes, sampling strategies and techniques must be selected, the chemical analyses must be reproducible and accurate, and the data evaluation protocols must be rigorous and appropriate.The aim of this thesis was to evaluate the use of pollutant profiles in order to assess complex patterns of environmental exposure. When combined with multivariate data analysis (MVDA) a maximum of information may be extracted from analytical data. Nevertheless, good quality data is essential for correct evaluation of the environmental phenomena under investigation. The precision and accuracy of a solid phase assisted liquid extraction method was therefore assessed by comparison to a reference method. The validated method was used in two human exposure studies. The concentrations of PCBs and dioxins were determined in human tissues from general populations in Sweden and Spain. Although it was concluded that the populations were exposed to similar degree to PCBs and dioxins, principal component analysis (PCA) showed that the compound profiles differed between the populations. PCA was also used to differentiate between occupationally exposed workers and matched controls and between exposed workers with recent and earlier exposure. In addition, the analysis indicated that the differences in PCB patterns in workers with recent and earlier exposure were related to differences in the metabolic degradation rates of individual PCBs. The PCA model was further used to select PCB congeners that were representative of each group.Finally, the emission of polycyclic aromatic hydrocarbons (PAHs) in a traffic tunnel was estimated by measuring 29 individual PAHs. The sampling periods were chosen to reflect a maximum variation in the traffic composition. An excellent prediction of the percentage of heavy-duty vehicles was obtained using partial least squares (PLS) regression. It was shown by PCA that it might be possible to predict source compositions at other locations with the aid of multivariate statistical tools. Thus, properly gathered pollutant profiles and MVDA may be combined to extract a large amount of significant information from environmental source and exposure data.
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