| 1. |
- Karl, M., et al.
(författare)
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Uncertainties in assessing the environmental impact of amine emissions from a CO2 capture plant
- 2014
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Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 14:16, s. 8533-8557
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Tidskriftsartikel (refereegranskat)abstract
- In this study, a new model framework that couples the atmospheric chemistry transport model system Weather Research and Forecasting-European Monitoring and Evaluation Programme (WRF-EMEP) and the multimedia fugacity level III model was used to assess the environmental impact of in-air amine emissions from post-combustion carbon dioxide capture. The modelling framework was applied to a typical carbon capture plant artificially placed at Mongstad, on the west coast of Norway. The study region is characterized by high precipitation amounts, relatively few sunshine hours, predominantly westerly winds from the North Atlantic and complex topography. Mongstad can be considered as moderately polluted due to refinery activities. WRF-EMEP enables a detailed treatment of amine chemistry in addition to atmospheric transport and deposition. Deposition fluxes of WRF-EMEP simulations were used as input to the fugacity model in order to derive concentrations of nitramines and nitrosamine in lake water. Predicted concentrations of nitramines and nitrosamines in ground-level air and drinking water were found to be highly sensitive to the description of amine chemistry, especially of the night-time chemistry with the nitrate (NO3) radical. Sensitivity analysis of the fugacity model indicates that catchment characteristics and chemical degradation rates in soil and water are among the important factors controlling the fate of these compounds in lake water. The study shows that realistic emission of commonly used amines result in levels of the sum of nitrosamines and nitramines in ground-level air (0.6-10 pgm(-3)) and drinking water (0.04-0.25 ng L-1) below the current safety guideline for human health that is enforced by the Norwegian Environment Agency. The modelling framework developed in this study can be used to evaluate possible environmental impacts of emissions of amines from post-combustion capture in other regions of the world.
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| 2. |
- Bialk-Bielinska, A., et al.
(författare)
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Hydrolysis of sulphonamides in aqueous solutions
- 2012
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Ingår i: Journal of Hazardous Materials. - : Elsevier BV. - 0304-3894. ; 221-222, s. 264-274
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Tidskriftsartikel (refereegranskat)abstract
- Hydrolysis is one of the most common reactions controlling abiotic degradation and is one of the main paths by which substances are degraded in the environment. Nevertheless, the available information on this process for many compounds, including sulphonamides (a group of antibiotic drugs widely used in veterinary medicine), is very limited. This is the first study investigating the hydrolytic stabilities of 12 sulphonamides, which were determined according to OECD guideline 111 (1st category reliability data on the basis of regulatory demands on data quality for the environmental risk assessment of pharmaceuticals). Hydrolysis behaviour was examined at pH values normally found in the environment. This was prefaced by a discussion of the acid-base properties of sulphonamides. All the sulphonamides tested were hydrolytically stable at pH 9.0, nine (apart from sulphadiazine, sulphachloropyridazine and sulphamethoxypyridazine) were stable in this respect at pH 7.0 and two (sulphadiazine and sulphaguanidine) at pH 4.0 (hydrolysis rate <= 10%; t(0.5(25 degrees c)) > 1 year). The degradation products were identified, indicating two independent mechanisms of this process. Our results show that under typical environmental conditions (pH and temperature) sulphonamides are hydrolytically stable with a long half-life; they thus contribute to the on-going assessment of their environmental fate. (C) 2012 Elsevier B.V. All rights reserved.
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| 3. |
- Bohn, Pernille, et al.
(författare)
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Abiotic degradation of antibiotic ionophores
- 2013
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Ingår i: Environmental Pollution. - 0269-7491 .- 1873-6424. ; 182, s. 177-183
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Tidskriftsartikel (refereegranskat)abstract
- Hydrolytic and photolytic degradation were investigated for the ionophore antibiotics lasalocid, monensin, salinomycin, and narasin. The hydrolysis study was carried out by dissolving the ionophores in solutions of pH 4, 7, and 9, followed by incubation at three temperatures of 6, 22, and 28 °C for maximum 34 days. Using LC–MS/MS for chemical analysis, lasalocid was not found to hydrolyse in any of the tested environments. Monensin, salinomycin, and narasin were all stable in neutral or alkaline solution but hydrolysed in the solution with a pH of 4. Half-lives at 25 °C were calculated to be 13, 0.6, and 0.7 days for monensin, salinomycin, and narasin, respectively. Absorbance spectra from each compound indicated that only lasalocid is degraded by photolysis (half-life below 1 h) due to an absorbance maximum around 303 nm, and monensin, salinomycin, and narasin are resistant to direct photolysis because they absorb light of environmentally irrelevant wavelengths.
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| 4. |
- Alling, Vanja, 1978-
(författare)
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Terrestrial organic carbon dynamics in Arctic coastal areas : budgets and multiple stable isotope approaches
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Arctic rivers transport 31-42 Tg organic carbon (OC) each year to the Arctic Ocean, which is equal to 10% of the global riverine OC discharge. Since the Arctic Ocean only holds approximately 1% of the global ocean volume, the influence of terrestrially derived organic carbon (OCter) in the Arctic Ocean is relatively high. Despite the global importance of this region the behavior of the, by far largest fraction of the OCter, the dissolved organic carbon (DOC) in Arctic and sub-arctic estuaries is still a matter of debate. This thesis describes data originating from field cruises in Arctic and sub-arctic estuaries and coastal areas with the aim to improve the understanding of the fate of OCter in these areas, with specific focus on DOC. All presented studies indicate that DOCter and terrestrially derived particulate organic carbon (POCter) are subjected to substantial degradation in high-latitude estuaries, as shown by the non-conservative behavior of DOC in the East Siberian Arctic Shelf Seas (ESAS) (paper I) and the even more rapid degradation of POC in the same region (paper II). The removals of OCter in Arctic shelf seas were further supported by multiple isotope studies (paper III and IV), which showed that a use of 13C/12C in both OC and DIC, together with 34S/32S is a powerful tool to describe the sources and fate of OCter in estuaries and coastal seas. High-latitude estuaries play a key role in the coupling between terrestrial and marine carbon pools. In contrast to the general perception, this thesis shows that they are not only transportation areas for DOCter from rivers to the ocean, but are also active sites for transformation, degradation and sedimentation of DOCter, as well as for POCter. In a rapidly changing climate, the importance of these areas for the coupling between inorganic and organic carbon pools cannot be underestimated.
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| 5. |
- Dimarogona, M., et al.
(författare)
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Lignin boosts the cellulase performance of a GH-61 enzyme from Sporotrichum thermophile
- 2012
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Ingår i: Bioresource Technology. - : Elsevier BV. - 0960-8524 .- 1873-2976. ; 110, s. 480-487
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Tidskriftsartikel (refereegranskat)abstract
- An enzyme belonging to the glycoside hydrolase family 61 from the thermophilic fungus Sporotrichum thermophile, was functionally expressed in the methylotrophic yeast Pichia pastoris under the transcriptional control of the alcohol oxidase (AOX1) promoter. The enzyme hydrolyzed barley beta-glucan, carboxymethyl cellulose, lichenan, wheat arabinoxylan and birchwood xylan showing optimal activity at pH 8 and 65 degrees C. A 2:1 mixture of Celluclast 1.5 L and StCel61a was capable of increasing the degree of spruce conversion by 42%. The use of substrates with varying lignin content permitted the detection of a dependence of the enhancing capacity of StCel61a on the radical scavenging capacity of the different lignocellulosics. In the presence of a reductant, StCel61a boosted the efficiency of a mixture of purified cellulases (EGII, CBHI, beta-GLUC) by 20%. The synergistic activity exhibited by StCel61a and its dependence on reducing substances provide guidelines for process design towards the production of economically viable bioethanol.
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| 6. |
- Mauerhofer, Volker
(författare)
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Lose less instead of win more : The failure of decoupling and perspectives for competition in a degrowth economy
- 2013
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Ingår i: Environmental Values. - 0963-2719 .- 1752-7015. ; 22:1, s. 43-57
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Tidskriftsartikel (refereegranskat)abstract
- This paper aims to provide a comprehensive explanation for the likely failure in the decoupling of economic growth from environmental degradation, and also intends to offer perspectives on the new role of competition in a steady state or a degrowth economy. The analysis is based on five different scenarios, and uses the European Union as an example. It is concluded that we must prepare ourselves for a potential incompatibility between sustainability and economic growth. In this respect one can say that the current EU situation is in some ways already quite close to an economic system without growth, although far from sustainable as yet. Two of the four perspectives developed, regarding the new role of competition in an economy without growth, indicate an increase of direct and indirect competition over resources. The other two perspectives point out that regulatory public intervention as well as financial intervention will increase in order to ensure that - despite the revised role of competition - the poorest are still given a chance to develop (e.g. through basic minimum incomes), even in a degrowth economy.
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| 7. |
- Hylander, Kristoffer, et al.
(författare)
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Effects of Coffee Management on Deforestation Rates and Forest Integrity
- 2013
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Ingår i: Conservation Biology. - : Wiley. - 0888-8892 .- 1523-1739. ; 27:5, s. 1031-1040
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Tidskriftsartikel (refereegranskat)abstract
- Knowledge about how forest margins are utilized can be crucial for a general understanding of changes in forest cover, forest structure, and biodiversity across landscapes. We studied forest-agriculture transitions in southwestern Ethiopia and hypothesized that the presence of coffee (Coffea arabica)decreases deforestation rates because of coffee's importance to local economies and its widespread occurrence in forests and forest margins. Using satellite images and elevation data, we compared changes in forest cover over 37 years (1973-2010) across elevations in 2 forest-agriculture mosaic landscapes (1100 km(2) around Bonga and 3000 km(2) in Goma-Gera). In the field in the Bonga area, we determined coffee cover and forest structure in 40 forest margins that differed in time since deforestation. Both the absolute and relative deforestation rates were lower at coffee-growing elevations compared with at higher elevations (-10/20% vs. -40/50% comparing relative rates at 1800 m asl and 2300-2500 m asl, respectively). Within the coffee-growing elevation, the proportion of sites with high coffee cover (>20%) was significantly higher in stable margins (42% of sites that had been in the same location for the entire period) than in recently changed margins (0% of sites where expansion of annual crops had changed the margin). Disturbance level and forest structure did not differ between sites with 30% or 3% coffee. However, a growing body of literature on gradients of coffee management in Ethiopia reports coffee's negative effects on abundances of forest-specialist species. Even if the presence of coffee slows down the conversion of forest to annual-crop agriculture, there is a risk that an intensification of coffee management will still threaten forest biodiversity, including the genetic diversity of wild coffee. Conservation policy for Ethiopian forests thus needs to develop strategies that acknowledge that forests without coffee production may have higher deforestation risks than forests with coffee production and that forests with coffee production often have lower biodiversity value. Efectos de la Administracion Cafetalera sobre las Tasas de Deforestacion y la Integridad de los Bosques Resumen El conocimiento sobre como se utilizan los margenes de los bosques puede ser crucial para el entendimiento general de los cambios en la cubierta boscosa, la estructura de los bosques y la biodiversidad en el paisaje. Estudiamos transiciones bosque-agricultura en el suroeste de Etiopia y partimos de la hipotesis de que la presencia del cafe (Coffea arabica) disminuye las tasas de deforestacion por la importancia del cafe para las economias locales y su ocurrencia extensa en los bosques y los margenes de estos. Usando imagenes de satelite e informacion de elevacion, comparamos los cambios en la cubierta boscosa a traves de 37 anos (1973-2010) a lo largo de elevaciones en 2 paisajes mosaico de bosque y sembradios (1100 km(2) alrededor de Bonga y 3000 km(2) en Goma-Gera). En el campo en el area de Bonga determinamos la cobertura de cafe y la estructura del bosque en 40 margenes de bosque que difirieron en el tiempo desde la deforestacion. Tanto la tasa absoluta como la relativa de deforestacion fueron mas bajas en las elevaciones donde se cultiva cafe comparadas con las de elevaciones mas altas (-10/20% vs. -40/50% comparando tasas relativas en 1800 msnm y 2300-2500 msnm, respectivamente). Dentro de la elevacion donde se cultiva cafe, la proporcion de sitios con una alta cobertura de cafe (>20%) fue significativamente mas alta en los margenes estables (42% de los sitios que habian estado en la misma localidad durante el periodo entero) que en los margenes con cambios recientes (0% de los sitios donde la expansion anual de cultivos habian alterado el margen). El nivel de perturbacion y de estructura del bosque no difirio entre los sitios con 30% o 3% de cafe. Sin embargo, un creciente cuerpo de literatura sobre los gradientes de administracion del cafe en Etiopia reportan los efectos negativos del cafe sobre la abundancia de especies especialistas de bosques. Aunque sea cierto que la presencia de cafe disminuye la conversion de bosque a sembradios de cosecha anual, existe el riesgo de que la intensificacion de la administracion de cafe todavia amenace la biodiversidad del bosque, incluyendo la diversidad genetica del cafe silvestre. La politica de conservacion para los bosques etiopes entonces debe desarrollar estrategias que reconozcan que los bosques sin produccion cafetalera pueden tener riesgos mayores de deforestacion que los bosques con produccion cafetalera y que los bosques con produccion cafetalera seguido tienen un valor bajo de biodiversidad.
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| 8. |
- Kalmykova, Yuliya, 1981, et al.
(författare)
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Sorption and degradation of petroleum hydrocarbons, polycyclic aromatic hydrocarbons, alkylphenols, bisphenol A and phthalates in landfill leachate using sand, activated carbon and peat filters
- 2014
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Ingår i: Water Research. - : Elsevier BV. - 0043-1354 .- 1879-2448. ; 56, s. 246-257
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Tidskriftsartikel (refereegranskat)abstract
- Landfill leachates are repeatedly found contaminated with organic pollutants, such as alkylphenols (APs), phthalates and polycyclic aromatic hydrocarbons (PAHs) at levels exceeding water quality standards. It has been shown that these pollutants may be present in the colloidal and truly dissolved phase in contaminated water, making particle separation an inefficient removal method. The aim of this study was to investigate sorption and degradation of petroleum hydrocarbons (PHCs), selected APs, bisphenol A (BPA), phthalates and PAHs from landfill leachate using sand, granulated activated carbon (GAC) and peat moss filters. A pilot plant was installed at an inactive landfill with mixed industrial and household waste and samples were collected before and after each filter during two years.Leachate pre-treated in oil separator and sedimentation pond failed to meet water quality standards in most samples and little improvement was seen after the sand filter. These techniques are based on particle removal, whereas the analysed pollutants are found, to varying degrees, bound to colloids or dissolved. However, even highly hydrophobic compounds expected to be particle-bound, such as the PHCs and high-molecular weight PAHs, were poorly removed in the sand filter. The APs and BPA were completely removed by the GAC filter, while mass balance calculations indicate that 50–80% of the investigated phenols were removed in the peat filter. Results suggest possible AP degradation in peat filters. No evidence of phthalate degradation in the landfill, pond or the filters was found. The PHCs were completely removed in 50% and 35% of the measured occasions in the GAC and peat filters, respectively. The opposite trend was seen for removal of PAHs in GAC (50%) and peat (63%). Oxygenated PAHs with high toxicity were found in the leachates but not in the pond sediment. These compounds are likely formed in the pond water, which is alarming because sedimentation ponds are commonly used treatment techniques. The oxy-PAHs were effectively removed in the GAC, and especially the peat filter. It was hypothesized that dissolved compounds would adsorb equally well to the peat and GAC filters. This was not completely supported as the GAC filter was in general more efficient than peat.
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| 9. |
- Nyström, Magnus, et al.
(författare)
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Confronting Feedbacks of Degraded Marine Ecosystems
- 2012
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Ingår i: Ecosystems. - : Springer Science and Business Media LLC. - 1432-9840 .- 1435-0629. ; 15:5, s. 695-710
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Tidskriftsartikel (refereegranskat)abstract
- In many coastal areas, marine ecosystems have shifted into contrasting states having reduced ecosystem services (hereafter called degraded). Such degraded ecosystems may be slow to revert to their original state due to new ecological feedbacks that reinforce the degraded state. A better understanding of the way human actions influence the strength and direction of feedbacks, how different feedbacks could interact, and at what scales they operate, may be necessary in some cases for successful management of marine ecosystems. Here we synthesize interactions of critical feedbacks of the degraded states from six globally distinct biomes: coral reefs, kelp forests, seagrass beds, shallow soft sediments, oyster reefs, and coastal pelagic food webs. We explore to what extent current management captures these feedbacks and propose strategies for how and when (that is, windows of opportunity) to influence feedbacks in ways to break the resilience of the degraded ecosystem states. We conclude by proposing some challenges for future research that could improve our understanding of these issues and emphasize that management of degraded marine states will require a broad social-ecological approach to succeed.
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| 10. |
- Klett, Matilda, et al.
(författare)
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Non-uniform aging of cycled commercial LiFePO4//graphite cylindrical cells revealed by post-mortem analysis
- 2014
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Ingår i: Journal of Power Sources. - : Elsevier BV. - 0378-7753 .- 1873-2755. ; 257, s. 126-137
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Tidskriftsartikel (refereegranskat)abstract
- Aging of power-optimized commercial 2.3 Ah cylindrical LiFePO4//graphite cells to be used in hybrid electric vehicle is investigated and compared for three different aging procedures; (i) using a simulated hybrid electric vehicle cycle within a narrow SOC-range, (ii) using a constant-current cycle over a 100% SOC-range, and (iii) stored during three years at 22 degrees C. Postmortem analysis of the cells is performed after full-cell electrochemical characterization and discharge. EIS and capacity measurements are made on different parts of the disassembled cells. Material characterization includes SEM, EDX, HAXPES/XPS and XRD. The most remarkable result is that both cycled cells displayed highly uneven aging primarily of the graphite electrodes, showing large differences between the central parts of the jellyroll compared to the outer parts. The aging variations are identified as differences in capacity and impedance of the graphite electrode, associated with different SEI characteristics. Loss of cyclable lithium is mirrored by a varying degree of lithiation in the positive electrode and electrode slippage. The spatial variation in negative electrode degradation and utilization observed is most likely connected to gradients in temperature and pressure, that can give rise to current density and potential distributions within the jellyroll during cycling. (C) 2014 Elsevier B.V. All rights reserved.
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