| 1. |
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| 2. |
- Aurell, Johanna, et al.
(författare)
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Effects of sulfur on PCDD/F formation under stable and transient combustion conditions during MSW incineration
- 2009
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Ingår i: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 76:6, s. 767-773
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Tidskriftsartikel (refereegranskat)abstract
- SO2 levels in the flue gas from a laboratory-scale fluidized bed reactor combusting artificial municipal solid waste (MSW) were varied (resulting in four different SO2:HCl ratios 0, 0.2, 0.7 and 2.7 (by mass)) to study the effects of sulfur on the formation of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzothiophenes (PCDTs). Sampling was performed simultaneously at three fixed points in the post-combustion zone with temperatures of 400, 300 and 200 °C, under normal combustion conditions and both during and after transient combustion conditions. The findings indicate that sulfur has a greater inhibitory effect on PCDF formation than on PCDD formation and that the PCDD/PCDF ratio in the flue gas depends on both the SO2:HCl ratio in the flue gas and memory effects arising from transient combustion conditions. The results also indicate that the relative importance of different pathways shifts in the post-combustion zone; condensation products increasing with reductions in temperature and increases in residence time. However, these changes appear to depend on the SO2:HCl ratio in the flue gas and combustion conditions. Sulfur seems to inhibit the chlorination of PCDFs. A tendency for increased SO2 levels in the flue gas to increase levels of PCDTs was also detected, but the increases were much less significant than the reductions in PCDF levels.
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| 3. |
- Berglund, Åsa M. M., 1978-, et al.
(författare)
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Effects on the food-web structure and bioaccumulation patterns of organic contaminants in a climate-altered Bothnian Sea mesocosms
- 2023
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Ingår i: Frontiers in Marine Science. - : Frontiers Media S.A.. - 2296-7745. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Climate change is expected to alter global temperature and precipitation patterns resulting in complex environmental impacts. The proposed higher precipitation in northern Scandinavia would increase runoff from land, hence increase the inflow of terrestrial dissolved organic matter (tDOM) in coastal regions. This could promote heterotrophic bacterial production and shift the food web structure, by favoring the microbial food web. The altered climate is also expected to affect transport and availability of organic micropollutants (MPs), with downstream effects on exposure and accumulation in biota. This study aimed to assess climate-induced changes in a Bothnian Sea food web structure as well as bioaccumulation patterns of MPs. We performed a mesocosms-study, focusing on aquatic food webs with fish as top predator. Alongside increased temperature, mesocosm treatments included tDOM and MP addition. The tDOM addition affected nutrient availability and boosted both phytoplankton and heterotrophic bacteria in our fairly shallow mesocosms. The increased tDOM further benefitted flagellates, ciliates and mesozooplankton, while the temperature increase and MP addition had minor effect on those organism groups. Temperature, on the other hand, had a negative impact on fish growth and survival, whereas tDOM and MP addition only had minor impact on fish. Moreover, there were indications that bioaccumulation of MPs in fish either increased with tDOM addition or decreased at higher temperatures. If there was an impact on bioaccumulation, moderately lipophilic MPs (log Kow 3.6 - 4.6) were generally affected by tDOM addition and more lipophilic MPs (log Kow 3.8 to 6.4) were generally affected by increased temperature. This study suggest that both increased temperatures and addition of tDOM likely will affect bioaccumulation patterns of MPs in shallow coastal regions, albeit with counteracting effects.
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| 4. |
- Bjurlid, Filip, 1978-
(författare)
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Polybrominated dibenzo-p-dioxins and furans : from source of emission to human exposure
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Brominated flame retardants (BFRs), which are ubiquitous in modern life and the environment, are the major source for polybrominated dibenzo-p-dioxins and furans (PBDD/Fs). The knowledge about PBDD/Fs is lim-ited compared to other environmental pollutants, even though PBDD/Fs show similar toxicity as polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) which are considered to be among the most toxic man-made substances. The aim of the thesis was to provide a better understanding of PBDD/Fs by investigating the occurrence and distribution of PBDD/Fs in the following matrices: soot and gas from an accidental fire site which is a typical source of emission, blubber from marine mammals living in both far remote areas as well as areas close to anthropogenic sources, and finally in human milk from ten nursing mothers.PBDD/Fs was detected in blubber from pilot whales sampled around Faroe Islands, which proved the occurrence in marine mammals in a far remote area. The findings of PBDD/Fs in blubber from Baltic ringed seals showed slightly higher concentrations compared to the pilot whales, which is expected since the Baltic Sea in among the world’s most contam-inated water areas. In the pilot whales and the ringed seals, the average contribution from PBDD/Fs to the total (PCDD/F+PBDD/F) Total Equiv-alent Quantity (TEQ) was low, (1-8%). In gas and soot samples from the accidental fire site, PBDD/Fs were detected in all samples and the contri-bution of PBDD/Fs to the total TEQ was close to 100%. In the human milk samples, PBDD/Fs were detected in all samples and the average con-tribution of PBDD/Fs to the total TEQ was 40%. The results indicate that PBDD/Fs are of concern for human exposure, and should be monitored together with PCDD/Fs in future studies. Moreover, the occurrence at ac-cidental fire sites indicate that PBDD/Fs are a source for occupational ex-posure for firefighters and other professionals. The impact from PBDD/Fs on marine mammalians seems to be of less concern.
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| 5. |
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| 6. |
- Holmgren, Tomas, 1969-, et al.
(författare)
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A generic emission model to predict release of organic substances from materials in consumer goods
- 2012
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 437, s. 306-314
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Tidskriftsartikel (refereegranskat)abstract
- Organic chemicals may be released when consumer goods are used, contributing to environmental and human levels of potentially hazardous chemicals. A generic model was developed to predict emissions of organic chemicals from various materials in consumer products. The model involved three modules, which each predict a key parameter needed to calculate the mass of individual chemicals emitted. Partition coefficients between a material and the surrounding air were predicted using Abraham solvation parameters, diffusion coefficients in materials were calculated using the Piringer equation, and convective mass transfer coefficients were evaluated by applying the Chilton–Colburn analogy. The calculated emission rates from predicted parameters were evaluated and agreed well with literature data. The release of plasticizers from vinyl flooring used in Sweden was calculated to demonstrate the utility of the generic model. The estimated emitted masses of di(2-ethylhexyl)phthalate (DEHP), di-iso-nonylphthalate (DINP), and 1,2-cyclohexanedicarboxylic acid di-iso-nonyl ester (DINCH) in 2012 were 210 kg, 40 kg, and 3.6 kg respectively. Emissions from vinyl flooring were estimated for the period 1990 to 2035 and it was shown that the recent substitution of DEHP with DINP will help to reduce plasticizer emissions. Model calculations for alternative plasticizers revealed that DINCH would yield similar emissions to DINP, whereas use of diethyl hexyl-iso-sorbide or diethyl hexyl adipate would result in higher emissions.
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| 7. |
- Holmgren, Tomas, 1969-, et al.
(författare)
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Measurement and modelling of organophosphates leaching from concrete to water
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Organophosphate triesters used as additives in materials are leaching into the environment and have been found as pollutants in both water and sewage samples. Concrete is one of the most commonly used materials in the world and often contains tributyl phosphate (TBP) and triisobutyl phosphate (TiBP) as anti-foaming agents. In the present study, leaching of TBP and TiBP from concrete to water was measured over 16 weeks under laboratory conditions. The release was initially high (TBP 2900 ± 1060 10 μg/m2h; TiBP 8500 ± 800 μg/m2h), and then dropped to a low stable level over a six-week period. A generic model was developed to predict leaching of organic compounds to water. Three types of diffusion were modelled, dissolution from the surface, diffusion in cracks and pores, and diffusion in micro-pores in the concrete. The former type was assessed using the Nernst-Brunner dissolution and Fickian diffusion theory. The latter types required the use of three modules to model diffusion, solubilisation and 15 convective mass transfer processes separately. The boundary layer solubilisation was modelled using the Abraham solubility equation and solvation parameters taken from literature data. The results showed that the initial release of organophosphates from concrete to water can be significant (in some cases, >40% of the additive leaches out over the first few weeks) and that the long-term release of organophosphates from concrete constructions to the surrounding water can be accurately modelled. The model was applied to 20 estimate the release of TiBP to river water from the foundation of a bridge, resulting in a total loss of 2% of the additive over 8 years, with seasonal fluctuations in loss rate following changes in temperature and water flow. Due to the generic nature of the model, it can also be used to assess the leaching of other additives from concrete constructions to aquatic environments.
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| 8. |
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| 9. |
- Miller, Aroha, et al.
(författare)
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Temporal trends in dioxins (polychlorinated dibenzo-p-dioxin and dibenzofurans) and dioxin-like polychlorinated biphenyls in Baltic herring (Clupea harengus)
- 2013
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Ingår i: Marine Pollution Bulletin. - : Elsevier BV. - 0025-326X .- 1879-3363. ; 73:1, s. 220-230
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Tidskriftsartikel (refereegranskat)abstract
- Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyl (dl-PCBs) concentrations in Baltic herring (Clupea harengus) have been relatively stable since the mid to late 1990s. It is unclear why concentrations in Baltic herring are not following the observed decreases in other environmental matrices. Here, changes in long-term temporal trends in Baltic herring were examined. A number of biological variables were examined alongside the temporal trends to investigate whether fish biology e.g., growth (length, weight, age), lipid content, reproductive phase or fishing date may provide an explanation for the temporal trends observed. Significant (p < 0.05) decreasing trends were observed for PCDD/F toxic equivalents (TEQ(PCDD/F)) at three of the four sites (lipid weight (lw) and wet weight (ww), Swedish west coast lw only); however, other TEQ values e.g., TEQ(PCDD), TEQ(PCDF), TEQ(dl-PCB), TEQ(PCDD/F+dl-PCB) were inconsistent, decreasing at some sites but not others. In the most recent 10 years of data, fewer significant decreases were seen overall. Over the examined time period, significant decreases (Bothnian Bay, p < 0.01, southern Baltic Proper, p < 0.02) and increases (Swedish west coast, p < 0.02) in lipid content, growth dilution or lack thereof, and significant changes in age were observed. However herring were not randomly selected which biases this result. Continual efforts to decrease PCDD/F and dl-PCB emissions and to locate/reduce hotspots are necessary, while bearing in mind that herring biology may be impeding faster decreases of these chemicals.
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| 10. |
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| 11. |
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| 12. |
- Nording, Malin, 1976-, et al.
(författare)
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Evaluation of the structure/cross-reactivity relationship of polycyclic aromatic compounds using an enzyme-linked immunosorbent assay kit
- 2003
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Ingår i: Analytica Chimica Acta. - : Elsevier. - 0003-2670 .- 1873-4324. ; 487:1, s. 43-50
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Tidskriftsartikel (refereegranskat)abstract
- A commercially available enzyme-linked immunosorbent assay (ELISA) kit, the PAH soil test, was evaluated with regard to cross-reactivity. Phenanthrene in methanol was used as reference substance. Anthracene, naphthalene and fluorene were chosen as representatives of the 16 US-EPA priority-pollutant polycyclic aromatic hydrocarbons (PAHs). In addition, a number of polycyclic aromatic compounds (PACs), including methyl-, phenyl-, and carbonyl-PAHs, as well as NSO-heterocyclic PACs, found at former industrial sites, were chosen for elucidation of structure/cross-reactivity relationships. The study emphasizes the importance of a priori knowledge of sample composition for accurate interpretation of test results.
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| 13. |
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| 14. |
- Norman Haldén, Anna, et al.
(författare)
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Retention and maternal transfer of brominated dioxins in zebrafish (Danio rerio) and effects on reproduction, aryl hydrocarbon receptor-regulated genes, and ethoxyresorufin-O-deethylase (EROD) activity
- 2011
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Ingår i: Aquatic Toxicology. - Oxford : Elsevier. - 0166-445X .- 1879-1514. ; 102:3-4, s. 150-161
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Tidskriftsartikel (refereegranskat)abstract
- Brominated dioxins have recently been detected in Baltic Sea biota. Due to their similarities to the highly toxic chlorinated dioxins, concern has been raised about their potential biological effects. The present study investigated retention and effects of brominated dioxins in adult zebrafish, as well as maternal transfer and effects on offspring. We exposed adult zebrafish for nine weeks via feed to 2,3,7,8-tetrabromodibenzo-p-dioxin (TBDD) or to a mixture of brominated dioxins (Baltic Sea mixture), which was designed to reflect relative concentrations found in Baltic Sea biota. We studied spawning success, gonad morphology, hepatic vitellogenin gene expression, and offspring early life-stage development to investigate effects on zebrafish reproduction. Hepatic ethoxyresorufin-O-deethylase (EROD) activity and hepatic expression of a number of aryl hydrocarbon receptor (AHR)-regulated genes were studied to investigate if the brominated dioxins can activate gene transcription through the AHR pathway in zebrafish. In addition, glutathione reductase activity and expression of genes involved in adaptive responses to intracellular stress were studied to investigate potential stress effects of brominated dioxins. After nine weeks of exposure, all brominated dioxins spiked to the feed were detected in female fish and transferred to eggs. Exposure to the Baltic Sea mixture and TBDD clearly induced AHR-regulated genes and EROD activity. Exposure to TBDD reduced spawning success, altered ovarian morphology and reduced hepatic vitellogenin gene expression, which implies that TBDD has a similar effect pattern as the chlorinated analogue. Overall, our results show that dietary exposure to sublethal concentrations of brominated dioxins may impair reproductive physiology in fish and induce AHR-regulated genes. (C) 2011 Elsevier B.V. All rights reserved.
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| 15. |
- Olofsson, Ulrika, 1967-, et al.
(författare)
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Behavior and fate of anthropogenic substances at a Swedish sewage treatment plant
- 2010
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Ingår i: Water Science and Technology. - : IWA Publishing. - 0273-1223 .- 1996-9732. ; 62:12, s. 2880-2888
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Tidskriftsartikel (refereegranskat)abstract
- The behavior and fate of anthropogenic substances during sewage treatment were investigated at a sewage treatment plant (STP) in Sweden which uses mechanical, chemical, and biological methods for sewage treatment and anaerobic digestion of sludge. Influent and effluent water, and sludge from two specific treatment sites were sampled. Mass balances were calculated from measured concentrations of various substances and estimates of the mass flows (water, solids) throughout the process. The results show that the metals (As, Cd, Cr, Hg, Pb) and the majority of PCBs, PCDD/Fs, and PBDEs enter and leave the STP bound to particles. Triclosan and di-(2-ethylhexyl)phthalate adsorb to sludge to a high degree, while the metals (Co, Cu, Ni, Zn) and organophosphate esters seem to pass through the STP unaffected by the process. Generally, the STP was better in removing lipophilic than water soluble compounds. Most of the substances end up in anaerobically digested sludge in almost the same concentrations as in primary sludge. A fugacity based STP model was evaluated for its ability to predict the behavior and fate of the substances and was found feasible for lipophilic compounds. It did however produce poor predictions for water soluble compounds such as organophosphate esters (overestimated) and antibacterial agents (underestimated).
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| 16. |
- Olofsson, Ulrika, 1967-, et al.
(författare)
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Comprehensive mass flow analysis of Swedish sludge contaminants
- 2013
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 90:1, s. 28-35
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Tidskriftsartikel (refereegranskat)abstract
- A screening of metals, persistent organic pollutants, pharmaceuticals and personal care products (PPCPs),and other organic contaminants in sludge from seven Swedish sewage treatment plants (STPs) was performed in this study. This extensive screening provides information on mass flows of 282 compounds used in the Swedish society to sewage sludge. It reveals constant relative contaminant concentrations (ng-mg kg‑1 d.w.), except for some pesticides and perfluorinated compounds, indicating that these originate from broad usage and diffuse dispersion rather than (industrial) point sources. There was a five order of magnitude difference in the sum concentrations of the most and least abundant species (metals and polychlorinated dibenzo-p-dioxins and -furans, respectively). Lower total concentrations were found in sludge from STPs processing primarily food industry or household sewage. Proportions of the amounts used (in Sweden) found in sludge were lower for compounds that are present in consumer goods or are diffusely dispersed into the environment (0.01-1% recovered in sludge) than for compounds used as detergents or PPCPs (17–63%). In some cases, the recovery seemed to be affected by evaporation (e.g. octamethylcyclotetrasiloxane) or biotransformation (e.g. adipates) losses, while polychlorinated alkanes and brominated diphenyl ethers were recovered to disproportionately high degree (ca. 4%); likely due to incomplete statistics for imported goods.
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| 17. |
- Olofsson, Ulrika, 1967-, et al.
(författare)
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Time-trends of metals and organic contaminants in sewage sludge
- 2012
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Ingår i: Water Research. - : Elsevier. - 0043-1354 .- 1879-2448. ; 46:15, s. 4841-4851
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Tidskriftsartikel (refereegranskat)abstract
- The occurrence of chemicals in sludge from sewage treatment plants (STPs) is of concern for human health and the environment, especially since STPs are considered to be major secondary sources of many toxic chemicals into the environment. Land application of sewage sludge is an attractive option for sludge management, as it consists of nutrients and organic matter. However, before sludge can be used for this purpose, the content of hazardous substances needs to be reduced to levels considered safe. Legislations and regulations are put in place to minimize the release of harmful chemicals into the environment, e.g. via sewage sludge. Temporal trends analysis of sludge contaminants can be used to assess the effectiveness of such actions. Such analyses can be performed retrospectively, using sludge stored in environmental specimen banks, to investigate new or emerging environmental contaminants. The present study provides data from time-trend analyses of metals, persistent organic pollutants, pharmaceuticals, personal care products, and other organic compounds in sludge from Swedish STPs (based on seven years of measurements). The analysis showed that sludge is a suitable matrix for time-trend studies and it can take on average 12 years (range, 5-26 years) to track an annual change of ±10% (with a power of 80%). Statistically significant trends were found for 18 out of the 77 compounds subjected to analysis, of which 75% showed decreasing trends. Triclosan and the antibiotic norfloxacin followed the same trend as the national recorded usage and decreased annually by 65% and 60%, respectively. The opposite was true for the methylsiloxanes, which showed an annual average increase of about 30%. A downward trend (about 20% year−1) was observed for the polybrominated diphenylethers (PBDEs 154 and 183), while PBDE 209 increased by 16%. Further measurements are required to determine if the substitution of PBDEs by chlorinated paraffins or organophosphorus compounds have resulted in increased concentrations of the latter in sludge.
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| 18. |
- Olofsson, Ulrika, 1967-, et al.
(författare)
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Use of non-targeted environmetrics and comprehensive two-dimensional gas chromatography to assess sewage treatment plant removal efficiencies of structurally diverse organic contaminants
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- This study provides a new tool for the systematic and comprehensive screening of chemicals present in sewage and simultaneous assessment of sewage treatment plant (STP) removal efficiencies. Flow proportional samples were collected from a Swedish municipal STP, subjected to non-discriminating extraction and clean-up, and analyzed by comprehensive two-dimensional gas chromatography mass spectrometry (GCxGC-MS). Comparative environmetrics were used for outlier screening and removal efficiency assessment. The overall removal efficiency was good, but about 200 compounds were poorly extracted (<65%), of which 68 were tentatively identified based on their mass spectra and GC retention behavior. Most of the poorly extracted compounds were found in the aqueous phase of the effluent, with concentrations ranging from 0.2 to 12 000 ng L-1. Two amides (carbamazepine and diethyltoluamide (DEET)) were completely dissolved and not removed at all during treatment. Most of the compounds were aromatic (68%) or S,N,O-heterocyclic (31%) and chemically rather stable. All the compounds contained polar functional groups or moieties, which increase their water solubility and make them more prone to pass the STP unaffected. The new approach was used to identify new and emerging compounds, and generate information that could be used to improve current or design new STP treatment technologies.
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| 19. |
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| 20. |
- Wang, Shu Min, 1963, et al.
(författare)
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Growth of dilute nitrides and 1.3 μm edge emitting lasers on GaAs by MBE
- 2011
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Ingår i: Physica Status Solidi (B): Basic Research. - : Wiley. - 1521-3951 .- 0370-1972. ; 248:5, s. 1207-1211
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we report recent progresses on growth of dilute nitrides and 1.3 mu m lasers on GaAs using molecular beam epitaxy at Chalmers University of Technology, Sweden. Intense long wavelength light emission up to 1.71 mu m at room temperature has been achieved by using the N irradiation method and the low growth rate. It is also demonstrated that incorporation of N in relaxed InGaAs buffer grown on GaAs strongly enhances the optical quality of metamorphic InGaAs quantum wells. With the optimized growth conditions and the laser structures, we demonstrate 1.3 mu m GaInNAs edge emitting lasers on GaAs with state-of-the-art performances including a low threshold current density, a high-characteristic temperature, a 3 dB bandwidth of 17 GHz and uncooled operation at 10 Gbit/s up to 110 degrees C. The laser performances are comparable with the best reported data from the InGaAsP lasers on InP and is superior to the InAs quantum dot lasers on GaAs.
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| 21. |
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| 22. |
- Zhang, Wen, et al.
(författare)
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Evaluation of five filter media in column experiment on the removal of selected organic micropollutants and phosphorus from household wastewater
- 2019
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Ingår i: Journal of Environmental Management. - : ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD. - 0301-4797 .- 1095-8630. ; 246, s. 920-928
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Tidskriftsartikel (refereegranskat)abstract
- A bench-scale column experiment was performed to study the removal of 31 selected organic micropollutants (MPs) and phosphorus by lignite, xyloid lignite (Xylit), granular activated carbon (GAC), Polonite (R) and sand over a period of 12 weeks. In total 29 out of the 31 MPs showed removal efficiency > 90% by GAC with an average removal of 97 +/- 6%. Xylit and lignite were less efficient with an average removal of 80 +/- 28% and 68 +/- 29%, respectively. The removal efficiency was found to be impacted by the characterization of the sorbents and physicochemical properties of the compounds, as well as the interaction between the sorbents and compounds. For instance, Xylit and lignite performed well for relatively hydrophobic (log octanol/water partition coefficient (K-ow) >= 3) MPs, while the removal efficiency of moderately hydrophilic, highly hydrophilic and negatively charged MPs were lower. The organic sorbents were found to have more functional groups at their surfaces, which might explain the higher adsorption of MPs to these sorbents. The removal of several MPs improved after four weeks in sand, Xylit, GAC and lignite which may be related to increased biological activity and biofilm development. GAC and sand had limited ability to remove phosphorus (12 +/- 27% and 14 +/- 2%, respectively), while the calcium-silicate material Polonite (R) precipitated phosphorus efficiently and increased the total phosphorus removal from 12% to 96% after the GAC filter.
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