| 1. |
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| 2. |
- Hoffland, Ellis, et al.
(författare)
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The role of fungi in weathering
- 2004
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Ingår i: Frontiers in Ecology and Environment. - 1540-9295 .- 1540-9309. ; 2:5, s. 258-264
-
Tidskriftsartikel (refereegranskat)abstract
- No rock at the Earth’s surface escapes weathering. This process is the primary source of all the essential elements for organisms, except nitrogen and carbon. Since the onset of terrestrial life, weathering has been accelerated under the influence of biota. The study of biological weathering started at the end of the 19th century. Although the role of bacteria (Eubacteria, Archaea) has attracted a lot of interest, until recently the role of fungi has largely been neglected. More recently, however, fungal weathering has become an increasingly important focus of biogeochemical research.
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| 3. |
- Olsson, Susanna, et al.
(författare)
-
Copper(II) binding to dissolved organic matter fractions in municipal solid waste incinerator bottom ash leachate
- 2007
-
Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 41:12, s. 4286-4291
-
Tidskriftsartikel (refereegranskat)abstract
- Information on Cu speciation in municipal solid waste incineration (MSWI) bottom ash leachate is needed for Cu leaching predictions and toxicity estimates. The complexation of Cu with dissolved organic matter (DOM) in leachates from a stored MSWI bottom ash was studied potentiometrically using a Cu-ion selective electrode. More than 95% of the copper was bound to DOM in the hydrophilic fraction of the leachate, indicating that the hydrophilic acids contribute to Cu complex formation. The hydrophilic acids constituted 58% of the dissolved organic carbon in the ash leachate. Comparisons between experimental results and speciation calculations with the NICA-Donnan model and the Stockholm humic model indicated differences between the ash DOM and the natural DOM for which the models have been calibrated. The ratio of carboxylic binding sites to phenolic binding sites was 2 times larger in ash DOM, and the Cu-binding affinity of the former was stronger than accounted for by the generic Cu-binding parameters. The Cu-binding affinity of the phenolic sites, on the other hand, was weaker. When these parameters were adjusted, a good description of the experimental data was obtained.
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| 4. |
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| 5. |
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| 6. |
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| 7. |
- Andersson, Petra, et al.
(författare)
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Innovativa elsystem i byggnader : konsekvenser för brandsäkerhet
- 2019
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Det sker en snabb teknikutveckling i den elektriska miljön i byggnader, framförallt i våra bostäder. Ett exempel är lokal produktion av el, där solcellsinstallationer blir alltmer populära. Sådan elproduktion medför även förändringar i övriga delar av byggnaders elektriska infrastruktur, såsom DC-nät och i vissa fall energilagring i batterisystem. Utvecklingen sker till stor del som ett svar på behovet av mer hållbara lösningar, ur ett växthuseffektperspektiv, för vår elförsörjning, och förstärks bland annat av statligt stöd och ökad tillgänglighet på marknaden.Ny elektrisk teknologi kan leda till ökad brandrisk och denna förstudie har haft som mål att undersöka denna problematik. Metoden har varit workshops med intressenter och experter inom området, intervjuer, samt litteraturstudier.Av de studerade områdena förefaller solcellsanläggningar skapa störst utmaningar i framtiden om inget görs. Detta beror dels på bristfälligt regelverk men även på att dessa system är distribuerade i byggnaderna med flera delar som kan orsaka brand och att delar är exponerade för utomhusklimat vilket får stora konsekvenser vad gäller uppkomst av fel.Brandsäkerheten i samhället har sett ur ett långt tidsperspektiv väsentligt förbättrats. Detta har huvudsakligen drivits fram med hjälp av ett förbättrat regelverk, som ofta inkluderat förbättrade provnings- och kvalificeringsmetoder. En generell observation i detta projekt är att regelverket inte hinner utvecklas i samma takt som tekniken. Detta är en ofta återkommande utmaning inom brandsäkerhet, men gäller speciellt för de teknikområden som behandlas i denna rapport där utvecklingen går mycket snabbt, och de ingående komponenterna nästan uteslutande har stor inneboende brandpotential. Rapporten konstaterar att för att skapa ett relevant regelverk behövs tillämpad forskning, så kallad prenormativ forskning, inom prioriterade områden för att besvara de frågor som ställs vid formulerandet av nya regler och standarder. Exempel på områden som bör prioriteras är 1) komplettering av det än så länge magra statistiska underlaget för bränder i solcellsinstallationer med olycksutredningar, och studier av redan befintliga olycksutredningar, 2) studier av branddynamiken i solcellsinstallationer, såväl byggnadsapplicerade som integrerade, och såväl tak- som fasadmonterade sådana, 3) studier av ljusbågars uppkomst och hur dessa kan undvikas, alternativt hur det kan undvikas att de ger upphov till bränder, 4) skapa underlag för säker installation av batterilager, samt 5) kvalitetssäkring av så kallade second-life batterier, dvs. begagnade batterier, som används i batterilager.
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| 8. |
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| 9. |
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| 10. |
- Andersson, Petra, et al.
(författare)
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Satsning mot bostadsbränder
- 2014
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Ingår i: Brandposten. ; :50, s. 18-
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Tidskriftsartikel (populärvet., debatt m.m.)
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| 11. |
- Andres, B., et al.
(författare)
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Experimental analysis of stone wool sandwich composites exposed to constant incident heat fluxes and simulated parametric fires
- 2017
-
Ingår i: 15th International Conference and Exhibition on Fire and Materials 2017. - 9781510846746 ; 2, s. 503-516
-
Konferensbidrag (refereegranskat)abstract
- An experimental analysis of the fire behavior of stone wool composites with stainless steel and gypsum plasterboard linings was performed. The focus was to characterize the micro-scale behavior of stone wool, and identify the main processes occurring in stone wool composites when exposed to heat. Thermogravimetric analysis was applied to two different wools with varying densities and binder content in air and nitrogen atmospheres at 5, 10, and 20 K/min. Results show a low percentage of mass loss that could be linked to the low fraction of organic binder contained in the wool. Intermediate-scale composite assemblies were tested using the Heat-Transfer Inducing Rate System (H-TRIS). Specimens were composed of stainless steel-stone wool, and gypsum plasterboard-stone wool. Tests were performed at (1) constant low incident heat flux (7 kW/m2), (2) constant high incident heat flux (60 kW/m2), and (3) simulated parametric incident heat exposure. The results of these tests help to identify the relevant phenomena that should be taken into account when modelling building assemblies with stone wool cores (i.e. pyrolysis and combustion of the binder, water transport through the cross-section, and burning of paper).
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| 12. |
- Andres, Blanca, et al.
(författare)
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Response of stone wool–insulated building barriers under severe heating exposures
- 2018
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Ingår i: Journal of Fire Sciences. - : SAGE Publications. - 0734-9041 .- 1530-8049. ; 36:4, s. 315-341
-
Tidskriftsartikel (refereegranskat)abstract
- This article presents the experimental results of stone wool–layered sandwich constructions, with either steel or gypsum claddings, tested under four different heating exposures: 7 kW/m2 incident radiant heat flux exposure, 60 kW/m2 incident radiant heat flux exposure, parametric time–temperature curve exposure and ISO 834 standard time–temperature exposure. The test apparatus used were a movable radiant panel system, a mid-scale furnace (1.5 m3) and a large-scale furnace (15 m3). The results show that reduced-scale tests are capable of reproducing the heat transferred through the construction at large scale provided there is limited mechanical degradation. The results indicate that the availability of oxygen is fundamental to the fire behaviour of the sandwich composites tested. Reactions occurring in stone wool micro-scale testing, such as oxidative combustion of the binder or crystallisation of the fibres, have a limited effect on the temperature increase when wool is protected from air entrainment.
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| 13. |
- Andrés Valiente, Blanca, et al.
(författare)
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Experimental and thermal analysis of wall assemblies exposed to standard and parametric fires
- 2015
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Ingår i: First International Conference on structural safety under fire and blast (CONFAB). - 9780993012129
-
Konferensbidrag (refereegranskat)abstract
- The aim of this study is to assess the effect that different fire exposures have on the behaviour of gypsum plasterboard assemblies with known fire resistance rating. For this purpose a series of fire tests were performed on commonly used wall assemblies. Four different small scale samples were tested under ISO 834 and HCC standard fire curves. Additionally, one assembly was tested in an enclosure, with a pool fire used as a heat source. The results show that although there is a higher temperature exposure in HCC, the time criterion for standard classification is fulfilled in the small scale tests. A steeper rise of the temperature on the unexposed side for the HCC appears after 65 minutes in the worst case. In the pool fire test the highest temperature values measured on the unexposed side are closer to the values obtained in the HCC test, while the lower are below the ISO 834 results. 2D-heat transfer analysis was conducted on one of the assemblies tested. The aim was to evaluate if empirical thermal properties commonly assumed to model ISO 834 fire exposures are adequate for modelling other temperature-time exposures. The results show a need of further investigation on the thermal properties.
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| 14. |
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| 15. |
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| 16. |
- Arwidsson, Zandra, et al.
(författare)
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Remediation of heavy metal contaminated soil washing residues with amino polycarboxylic acids
- 2010
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Ingår i: Journal of Hazardous Materials. - : Elsevier BV. - 0304-3894 .- 1873-3336. ; 173:1-3, s. 697-704
-
Tidskriftsartikel (refereegranskat)abstract
- Removal of Cu, Pb, and Zn by the action of the two biodegradable chelating agents [S,S]-ethylenediaminedisuccinic acid (EDDS) and methylglycinediacetic acid (MGDA), as well as citric acid, was tested. Three soil samples, which had previously been treated by conventional soil washing (water), were utilized in the leaching tests. Experiments were performed in batches (0.3 kg-scale) and with a WTC-mixer system (Water Treatment Construction, 10 kg-scale). EDDS and MGDA were most often equally efficient in removing Cu, Pb, and Zn after 10-60 min. Nonetheless, after 10 d, there were occasionally significant differences in extraction efficiencies. Extraction with citric acid was generally less efficient, however equal for Zn (mainly) after 10 d. Metal removal was similar in batch and WTC-mixer systems, which indicates that a dynamic mixer system could be used in full-scale. Use of biodegradable amino polycarboxylic acids for metal removal, as a second step after soil washing, would release most remaining metals (Cu, Pb and Zn) from the present soils, however only after long leaching time. Thus, a full-scale procedure, based on enhanced metal leaching by amino polycarboxylic acids from soil of the present kind, Would require a pre-leaching step lasting several days in order to be efficient. (C) 2009 Elsevier B.V. All rights reserved.
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| 17. |
- Arwidsson, Zandra, et al.
(författare)
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Remediation of Metal Contaminated Soil by Organic Metabolites from Fungi I—Production of Organic Acids
- 2008
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Ingår i: Water, Air and Soil Pollution. - Berlin, Germany : Springer. - 0049-6979 .- 1573-2932. ; 205:1-4, s. 215-226
-
Tidskriftsartikel (refereegranskat)abstract
- Investigations were made on living strains offungi in a bioremediation process of three metal (lead)contaminated soils. Three saprotrophic fungi (Aspergillusniger, Penicillium bilaiae, and a Penicillium sp.) wereexposed to poor and rich nutrient conditions (no carbonavailability or 0.11 M D-glucose, respectively) andmetal stress (25 μM lead or contaminated soils) for5 days. Exudation of low molecular weight organicacids was investigated as a response to the metal andnutrient conditions. Main organic acids identified wereoxalic acid (A. niger) and citric acid (P. bilaiae).Exudation rates of oxalate decreased in response tolead exposure, while exudation rates of citrate were lessaffected. Total production under poor nutrient conditionswas low, except for A. niger, for which nosignificant difference was found between the poor andrich control. Maximum exudation rates were 20 μmoloxalic acid g^−1 biomass h^−1 (A. niger) and 20 μmolcitric acid g^−1 biomass h^−1 (P. bilaiae), in the presenceof the contaminated soil, but only 5 μmol organic acidsg^−1 biomass h^−1, in total, for the Penicillium sp. Therewas a significant mobilization of metals from the soilsin the carbon rich treatments and maximum release ofPb was 12% from the soils after 5 days. This was notsufficient to bring down the remaining concentration tothe target level 300 mg kg^−1 from initial levels of 3,800,1,600, and 370 mg kg^−1in the three soils. Target levelsfor Ni, Zn, and Cu, were 120, 500, and 200 mg kg^−1,respectively, and were prior to the bioremediationalready below these concentrations (except for Cu Soil1). However, maximum release of Ni, Zn, and Cu was28%, 35%, and 90%, respectively. The release of metalswas related to the production of chelating acids, but alsoto the pH-decrease. This illustrates the potential to usefungi exudates in bioremediation of contaminated soil.Nonetheless, the extent of the generation of organicacids is depending on several processes and mechanismsthat need to be further investigated.
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| 18. |
- Arwidsson, Zandra, et al.
(författare)
-
Remediation of soils and sludges containing organic contaminants as well as metals – soil-wash procedures combining biodegradation, chemical complexation and mechanical separation of particulate matter
- 2009
-
Konferensbidrag (refereegranskat)abstract
- Soil contamination is an urgent issue world wide. More than 83,000 contaminated sites have been identified in Sweden alone, of which approximately some 4,000 require treatment in the near future. Most of the sites carry a mixture of contaminants, metals as well as persistent organics. Most soil remediation efforts are made ex situ, which means that the soil or sludge is dug up and transported to a facility for treatment, or simply for deposition. The aim of the present project is to design a strategy for ex situ treatment of soils with mixed contaminants. A variety of soils and sludges from different sites (around 10), essentially all with organic as well as inorganic (metallic) contaminants, have been selected for experimental studies in laboratory and pilot scale: Military sites (metals, explosives), wood preservation sites (PAHs, As, metals), industrial sites (metals, hydrocarbons, mercury, dioxins and others). Of particular importance in the present study are:Metals – Pb, Cu, Zn, Cr, Hg, as well as As Organics – PAHs, nitro aromatics, dioxinsA number of processes are selected and applied: •Biodegradation - use of commercially available cultures, as well as bacteria cultivated from the contaminated site itself •Mobilisation of organics - use of surface active agents •Mobilisation of metals - use of (1) complexing microbial metabolites produced in the soil (by fungii in paricular), (2) complexing agents generated by degradation of natural organic products (polyhydroxy carboxylic acids), and (3) artificial complexing agents (polyamino carboxylic acids).Biodegradation is performed in batches (anaerobic in most cases), while release and mobilisation of contaminants from soil aggregates are achieved during soil-wash performed in a dynamic system where wash solution is forced through the soil under high pressure (the WTC-process). The efficiency of biodegradation and subsequent soil-wash under various conditions is evaluated from chemical analysis, but also by several ecotoxicological tests. Some results are given that illustrates suitable strategies for treatment of mixed contaminated soil from real sites (soil) as well as for treatment of residues from industrial production (sludges etc).
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| 19. |
- Audouin, L., et al.
(författare)
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Quantifying differences between computational results and measurements in the case of a large-scale well-confined fire scenario
- 2011
-
Ingår i: Nuclear Engineering and Design. - : Elsevier BV. - 1872-759X .- 0029-5493. ; 241:1, s. 18-31
-
Tidskriftsartikel (refereegranskat)abstract
- The objective of this work was to quantify comparisons between several computational results and measurements performed during a pool fire scenario in a well-confined compartment. This collaborative work was initiated under the framework of the OECD fire research program and involves the most frequently used fire models in the fire community, including field and zone models. The experimental scenario was conducted at the French Institut de Radioprotection et de Surete Nucleaire (IRSN) and deals with a full-scale liquid pool fire in a confined and mechanically ventilated compartment representative for nuclear plants. The practical use of different metric operators and their ability to report the capabilities of fire models are presented. The quantitative comparisons between measurements and numerical results obtained from "open" calculations concern six important quantities from a safety viewpoint: gas temperature, oxygen concentration, wall temperature, total heat flux, compartment pressure and ventilation flow rate during the whole fire duration. The results indicate that it is important to use more than one metric for the validation process in order to get information on the uncertainties associated with different aspects of fire safety. (C) 2010 Elsevier B.V. All rights reserved.
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| 20. |
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| 21. |
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| 22. |
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| 23. |
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| 24. |
- Axelsson, Jesper, et al.
(författare)
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Use of CFD models for development of test methods
- 2001
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Ingår i: Interflam 2001. International Interflam Conference. 9th proceedings. Vol. 1. September 17-19.. - : Interscience communications Ltd.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 25. |
- Barton, John, et al.
(författare)
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The effect of oxygen concentration on selected industrial products in the open controlled atmosphere cone calorimeter
- 2022
-
Ingår i: Fire and Materials. - : Wiley. - 0308-0501 .- 1099-1018. ; 46:4, s. 617-627
-
Tidskriftsartikel (refereegranskat)abstract
- Past research on the effect of oxygen concentration on the heat release rate and carbon monoxide yield has focused on materials in isolation and there is a lack of research that studies end-use products. This paper investigates the effect of oxygen concentration on the heat release rate per unit area (HRRPUA) and carbon monoxide yield for two different cables and a mineral oil used as an operating fluid for vacuum pumps. A standard cone calorimeter was used to conduct the tests at an ambient oxygen concentration of 21% and an open controlled atmosphere cone calorimeter (OCACC) was used for the tests conducted below 21%. The OCACC allows cone calorimeter tests to be run at different oxygen concentrations by attaching a chamber to the standard cone calorimeter. The effects of oxygen concentration on the HRRPUA and carbon monoxide yield for the cables were limited when there was flaming over the entire exposed surface area. For the mineral oil, there was a large decrease in the HRPPUA at a reduced oxygen concentration, but the carbon monoxide yield appeared to be unaffected.
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| 26. |
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| 27. |
- Bhargava, Abhishek, et al.
(författare)
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Performance analysis of a heat transfer and sub-grid chemical reaction distributed activation energy model for fire simulations
- 2019
-
Ingår i: Journal of Fire Sciences. - : SAGE Publications. - 0734-9041 .- 1530-8049. ; 37:1, s. 18-46
-
Tidskriftsartikel (refereegranskat)abstract
- A heat transfer and sub-grid chemical reaction kinetic model for solid phase combustion of a charring polymer is presented based on distributed reactivity modeling approach. The model is used to compute flammability parameters of a polymer sheet of a given thickness to simulate test results of a cone calorimeter experiment. Comparison of model simulations with cone calorimeter test data shows that it gives reasonable prediction of mass loss rate, heat release rate, and total heat released of poly-vinyl chloride (PVC) and ethyl vinyl acetate–aluminum tri-hydroxide (EVA-ATH). The solution of governing equations with the current form of distributed reactivity modeling model poses numerical challenges due to appearance of a double integral in the chemical reaction model. Hence, an analytical approximation has been derived to solve mass and energy conservation equations representing the model. Simulation results indicate that with the approximated form of the distributed reactivity modeling model, along with the input parameters retrieved from literature, the model shows comparatively good predictions for EVA-ATH for mass loss rate, heat release rate, and total heat released, but calculates under-predicted values for PVC.
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| 28. |
- Bhargava, Abhishek, et al.
(författare)
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Pyrolysis modeling of PVC and PMMA using a distributed reactivity model
- 2016
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Ingår i: Polymer Degradation and Stability. - : Elsevier BV. - 0141-3910. ; 129, s. 199-211
-
Tidskriftsartikel (refereegranskat)abstract
- The thermal decomposition kinetics of poly(vinyl chloride) (PVC) and poly(methyl methacrylate) (PMMA) was studied by thermogravimetry using non isothermal experiments. A detailed kinetic analysis was done using the isoconversional methods (model-free) (including Friedman, Kissinger-Akhaira-Sunose (KAS) and Kissinger methods) and distributed reactivity model (model-fitting). The overall aim was to retrieve kinetic parameters of the model describing the differential thermogravimetric (DTG) curve. For distributed reactivity models, both double and multi-Gaussian methods were used to explain the thermal decomposition process in these polymers. Apparent kinetic parameters were retrieved using optimization calculations with a newly developed computer code using MATLAB® involving pattern search algorithm. Modeling results were compared with the experimental data obtained in a simultaneous thermal analyzer (STA). Agreement between experimental tests and simulations showed good results for fire modeling applications for these polymers.
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| 29. |
- Bhargava, Abhishek, et al.
(författare)
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Pyrolysis modeling of pvcusing distributed activation energy model-micro scale testing
- 2017
-
Ingår i: Proceedings of the International Conference on Applications of Structural Fire Engineering, ASFE 2015. - : Czech Technical University in Prague - Central Library. - 2336-7318. - 9788001061947
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Konferensbidrag (refereegranskat)abstract
- Polyvinyl chloride (PVC) is a common thermoplastic whichfinds widespread applications in the construction industry for usage inceiling linings, flooring materials, electrical cables and roofing materials. Several fire requirements are put on these types of applications. For fire safety engineering and product development, thermo-chemical decomposition modeling of PVC isrequired. The FIRETOOLS project investigates the possibilities to predict real scale fire behavior of building products, content and barriers by means of using material data on successively increasing scale. This paper focuses on the material modeling and studiesthe thermo-chemical decomposition of PVC using Distributed Activation Energy Model (DAEM).
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| 30. |
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| 31. |
- Blomqvist, Per, et al.
(författare)
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An experimental study of spontaneous ignition in storages of wood pellets
- 2007
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Ingår i: 10th International Conference - Fire and Materials 2007.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This article focuses on experimental studies of self-heating characteristics of wood pellets. Controlled experiments have been conducted in physical scales from 1 dm3 to 4 m3 with wood pellets. Basket tests have been conducted according to the "crossing-point method" to derive kinetic data on the exothermic reactions responsible for self-heating and eventually spontaneous ignition. The kinetic data was used in the planning of the large-scale experiments for predictions of approximate critical temperatures. The experiments in the 1 m3 scale were set-up basically as an enlargement of the basket tests to obtain validation experiments with controlled boundary conditions in a reasonable large scale. Several experiments were conducted and spontaneous ignition was seen in the centre of the pellet bulk at an ambient temperature of 115C. The close to real-scale experiments with 4 m3 wood pellets filled in a 6 m high silo were not strictly self heating experiments, instead a core shaped heating element was allowed to initiate the pyrolysis in the pellets. Heat and gas production and transportation from the growing pyrolysis zone were mapped with a large number of measurement points in the pellets bulk and in the top of the silo. The experimental work conducted gave kinetic data on the exothermic reactions in wood pellets, insight in self heating processes, a link between different experimental scales and knowledge regarding possibilities for detection of fires in storages of wood pellets.
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| 32. |
- Blomqvist, Per, et al.
(författare)
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Biofuels
- 2005
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Ingår i: 2nd International Symposium on Tunnel Safety & Security..
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Konferensbidrag (refereegranskat)
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| 33. |
- Blomqvist, Per, et al.
(författare)
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Fires in storages of biofuels
- 2007
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Ingår i: Fire and Materials 2007 Proceedings.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 34. |
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| 35. |
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| 36. |
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| 37. |
- Bray, Robert John, et al.
(författare)
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A comparison of carbon monoxide yields and particle formation at various global equivalence ratios in vitiated and under-ventilated conditions
- 2023
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Ingår i: Fire Safety Journal. - 0379-7112. ; 141
-
Tidskriftsartikel (refereegranskat)abstract
- There have been previous studies comparing experimental methods for the purpose of capturing gaseous yields at a range of global equivalence ratios. However, no work has investigated the capability of the open controlled atmosphere cone calorimeter for collecting such data where its two modes of operation are directly compared. The aim of this study is to compare carbon monoxide yields collected using vitiated and under-ventilated modes of atmospheric control in order to identify the preferable method of replicating carbon monoxide yields reported from larger scale enclosure fire experiments. Cone irradiances of 30, 50 and 65 kW/m2 were applied to PMMA and plywood samples. Vitiated tests were conducted using a mixed air/diluent gas, with an inflow rate of either 100, 150 or 180 L/min, resulting in a reduced oxygen concentration of 17.5 vol. %. Under-ventilated tests were conducted using flow rates of 5, 10 and 20 L/min in an air atmosphere. Particle formations and emissions were also measured using a particle analyser and have been reported herein. Results indicate that the under-ventilated mode of equivalence ratio control offers a more promising method of capturing species yields with favourable comparisons to other bench scale methods.
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| 38. |
- Bray, Robert John, et al.
(författare)
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Burning material behaviour in hypoxic environments : An experimental study examining a representative storage arrangement of acrylonitrile butadiene styrene, polyethylene bubble wrap, and cardboard layers as a composite system
- 2022
-
Ingår i: Fire and Materials. - : Wiley. - 0308-0501 .- 1099-1018. ; 46:1, s. 313-328
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Tidskriftsartikel (refereegranskat)abstract
- Cone calorimeter and controlled atmosphere cone calorimeter experiments were conducted on various samples. The intent of the tests was to examine the behavior of uniform and composite samples in a range of thicknesses, irradiances, and oxygen concentrations. Single, uniform layers of acrylonitrile butadiene styrene (ABS) were compared to a composite mix, comprising of ABS with a surface layer of cardboard and a secondary layer of polyethylene bubble wrap (intended to represent a potential storage arrangement). The horizontal samples have been tested at irradiances of 25 and 50 kW/m2 and oxygen concentrations of 20.95%, 17%, and 15% to examine a range of significant variables. Results for the uniform arrangement indicated various correlations, previously observed in the works of others, such as the relationships typically described between applied heat flux, ignitability, heat release rate and the effect of the introduction of hypoxic conditions. However, results were shown to change significantly when samples were arranged to feature composite layers. A hypothesized cause of the behavioral change, namely the soot and char residual introduced from the incomplete combustion of the cardboard layer, highlights further important variables that require consideration in material testing under hypoxic conditions. Such variables, namely specific material behaviors and sample orientation, must be sufficiently captured in the design methodologies of systems reliant upon the introduction of hypoxic conditions. It is concluded that sufficiently capturing a wider range of variables in burning materials under hypoxic conditions will introduce further design resilience and help optimize fire protection/prevention methods.
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| 39. |
- El Houssami, Mohamad, et al.
(författare)
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EUFireStat Project - Final report
- 2022
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- EU FireStat project brings together the knowledge and experience of nine different international fire safety institutions. The project maps the existing fire data collected across Member States and proposed meaningful data sets to allow decisions on fire safety at Member State and at EU level. This project was carried out by a consortium composed of nine international fire safety institutions: Efectis, NFPA, DBI, University of Edinburgh, BAM, VFDB, CTIF, Unviersity of Lund and EuroFSA Further information: https://eufirestat-efectis.com/
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| 40. |
- 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
-
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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| 41. |
- Elgh-Dalgren, Kristin, et al.
(författare)
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Bioremediation of a soil industrially contaminated by wood preservatives : degradation of polycyclic aromatic hydrocarbons and monitoring of coupled arsenic distribution
- 2011
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Ingår i: Water, Air and Soil Pollution. - Dordrecht : Springer Netherlands. - 0049-6979 .- 1573-2932. ; 214:1-4, s. 275-285
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Tidskriftsartikel (refereegranskat)abstract
- Two commercially available aerobic bioremediation methods (Daramend® and BioSan) were utilized to study the aerobic biodegradation of polycyclic aromatic hydrocarbons (PAH) and the effect of the simultaneously present arsenic. The soil was collected at an old wood preservation site and the initial PAH16-concentration was 46 mg/kg, with mainly high molecular weight congeners. The As-concentration was105 mg/kg with low availability as assessed with sequential extraction. To enahce the availability of PAH, the effect of a non-ionic surfactant was evaluated. Degradation of both low and high molecular weight PAH was observed, however after 30 weeks, the degradation was generally low and no treatment was significantly better than the others. The treatments had, on the other hand, an effect on As-distribution, with increased As-concentration in the available fraction after treatment. This may be due to both the microbial activity and the presence of anoxic micro sites in the soil. The overall efficiency of the biological treatment was further evaluated using the standardized ecotoxicity test utilizing Vibrio fischeri (Microtox®). The toxicity test demonstrated that the bioremediation led to an increase in toxicity, especially in treatments receiving surfactant. The surfactant implied an increase in contaminant availability but also a decrease in surface tension, which might have contributed to the overall toxicity increase.
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| 42. |
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| 43. |
- Elgh-Dalgren, Kristin, 1980-, et al.
(författare)
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Laboratory and pilot scale soil washing of PAH and arsenic from a wood preservation site : Changes in concentration and toxicity
- 2009
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Ingår i: Journal of Hazardous Materials. - Amsterdam : Elsevier. - 0304-3894 .- 1873-3336. ; 172:2-3, s. 1033-1040
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Tidskriftsartikel (refereegranskat)abstract
- Soil washing of a soil with a mixture of both polycyclic aromatic hydrocarbons (PAH) and As was evaluated in laboratory and pilot scale, utilizing both single and mixtures of different additives. The highest level of decontamination was achieved with a combination of 0.213 M of the chelating agent MGDA and 3.2xCMC* of a nonionic, alkyl glucoside surfactant at pH 12 (Ca(OH)2). This combination managed to reach Swedish threshold values within 10 min of treatment when performed at elevated temperature (50°C), with initial contaminant concentrations of As = 105±4 mg/kg and US-EPA PAH16 = 46.0±2.3 mg/kg. The main mechanisms behind the removal were the pH-effect for As and a combination of SOM-ionization as a result of high pH and micellar solubilization for PAHs. Implementation of the laboratory results utilizing a pilot scale equipment did not improve the performance, which may be due to the shorter contact time between the washing solution and the particles, or changes in physical characteristics of the leaching solution due to the elevated pressure utilized. The ecotoxicological evaluation, Microtox®, demonstrated that all soil washing treatments increased the toxicity of soil leachates, possibly due to increased availability of contaminants and toxicity of soil washing solutions to the test organism.
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| 44. |
- Elgh-Dalgren, Kristin, et al.
(författare)
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Re-cycling of remediated soil : evaluation of leaching tests as tools for characterization
- 2011
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Ingår i: Waste Management. - : Pergamon Press. - 0956-053X .- 1879-2456. ; 31:2, s. 215-224
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Tidskriftsartikel (refereegranskat)abstract
- In Sweden, leaching tests with deionized water (D.W.) are frequently utilized in risk assessment, but implementation of these results to evaluate the risk of spreading in the environment is difficult. One problem is that most leaching procedures only consider heavy metals release, whereas organic pollutants are left out. The aim of the present study was to assess the possible pollutant mitigation in four remediated soils, three with heavy metals and one with polycyclic aromatic hydrocarbons (PAH), utilizing three different leaching solutions: D.W., a weak ionic solution (0.001 M CaCl2) and an artificially made soil water (ASW). In general, batch leaching implied larger contaminant removal than column leaching, possibly due to the more rough treatment of the soil particles, and guidelines would at times be exceeded by batch leaching but not column leaching. Utilization of CaCl2 was found to release much less heavy metal than D.W., whereas the metals mobilized by ASW were removed from solution by the filtration of soil leachates. Low molecular weight PAH was most efficiently mobilized by CaCl2, while D.W. worked better for high molecular weight PAH. Despite very low initial PAH-concentrations, tap- and groundwater criteria were exceeded by all leaching solutions.
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| 45. |
- Elgh-Dalgren, Kristin, 1980-
(författare)
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Remediation of materials with mixed contaminants : treatability, technology and final disposal
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Contaminated soils are a large issue worldwide and much effort has been made to find efficient remediation methods. At many contaminated sites, mixtures of different contaminants with different properties are present, which may lead to additional problems, and thus additional costs, during the remediation process. This thesis presents the results from soil remediation of two mixed contaminated soils, containing explosives and heavy metals and polycyclic aromatic hydrocarbons (PAH) and arsenic, respectively. The results demonstrate that bioremediation may be an efficient method for moderate explosives concentration, but that too high contaminant concentrations may prevent the biodegradation, measured by both chemical and ecotoxicological analyses. If the contaminant concentration is very high, soil washing with alkaline pH (~12, NaOH) may be a good alternative, which was observed to remove both explosives and heavy metals. For a PAH and arsenic contaminated soil, little degradation of organics was observed during the bioremediation. However, the arsenic present was re-distributed in the soil, which could potentially lead to increased availability and thus increased risk for contaminant spreading. Soil washing at alkaline pH (~12-13; Ca(OH)2) with a combination of a biodegradable non-ionic surfactant and a biodegradable chelating agent, executed at high temperature (50°C), reached treatment goals for both arsenic and PAH after 10 min treatment. Measurement of ecotoxicity using Microtox® demonstrated that remaining surfactant in the soil may lead to increased toxicity despite lower contaminant concentrations. Soil is a basically non-renewable resource and thus re-cycling of remediated soil ought to be commonly occurring. Yet, the re-cycling of remediated masses has so far been limited in Sweden, mainly because of the risk of spreading of pollutant remains. However, a recent proposition from the Swedish EPA opens for re-cycling, even though the thresholds are very conservative. Risk assessment of the remediated soil includes the utilization of leaching tests to estimate the risk of spreading of remaining pollutants. A comparison of the leaching from four remediated soils using three different leaching solutions reveals that leaching of both heavy metals and PAH occurs. In addition, differences between different legislations were observed, which could imply that the same soil could be re-cycled in one country (the Netherlands) but not another (Sweden).
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| 46. |
- Elgh-Dalgren, Kristin, 1980-, et al.
(författare)
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Simultaneous remediation of explosives and lead from contaminated soil by pH-adjustment
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Soil washing with pH-adjusted water was evaluated in two soils containing different concentrations of heavy metals and explosives. Overall, the most efficient treatment was with water adjusted to pH 12 by NaOH. For explosives, pH 12 removed significantly higher amounts (P<0.05) of RDX and TNT compared to pH 4 (adjusted with HNO3) and distilled water in a moderately contaminated soil (230 mg HMX/kg, 1340 mg RDX/kg, 450 mg TNT/kg). In a more highly contaminated soil (6080 mg HMX/kg, 28740 mg RDX/kg, 3120 mg TNT/kg), the pH 12-treatment was the most efficient for removal of TNT and 2,4-DNT. Explosives removal increased with treatment time, probably due to the kinetically slow processes underlying the explosives degradation. Mobilization of heavy metals was strongly dependent on pH, with pH 12 mobilizing more than pH 3. In addition, the change in distribution coefficient (Kd) was more pronounced for local contaminants Pb and Cd in comparison with Cu and Zn, which were present in background concentrations.
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| 47. |
- Finlay, Roger, et al.
(författare)
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The role of fungi in biogenic weathering in boreal forest soils
- 2009
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Ingår i: Fungal Biology Reviews. - : Elsevier. - 1749-4613 .- 1878-0253. ; 23:4, s. 101-106
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Tidskriftsartikel (refereegranskat)abstract
- In this article we discuss the possible significance of biological processes, and of fungi in particular, in weathering of minerals. We consider biological activity to be a significant driver of mineral weathering in forest ecosystems. In these environments fungi play key roles in organic matter decomposition, uptake, transfer and cycling of organic and inorganic nutrients, biogenic mineral formation, as well as transformation and accumulation of metals. The ability of lichens, mutualistic symbioses between fungi and photobionts such as algae or cyanobacteria, to weather minerals is well documented. The role of mycorrhizal fungi forming symbioses with forest trees is less well understood, but the mineral horizons of boreal forests are intensively colonised by mycorrhizal mycelia which transfer protons and organic metabolites derived from plant photosynthates to mineral surfaces, resulting in mineral dissolution and mobilisation and redistribution of anionic nutrients and metal cations. The mycorrhizal mycelia, in turn provide efficient systems for the uptake and direct transport of mobilised essential nutrients to their host plants which are large sinks. Since almost all (99.99. %) non-suberised lateral plant roots involved in nutrient uptake are covered by ectomycorrhizal fungi, most of this exchange of metabolites must take place through the plant-fungus interface. This idea is still consistent with a linear relationship between soil mineral surface area and weathering rate since the mycelia that emanate from the tree roots will have a larger area of contact with minerals if the mineral surface area is higher. Although empirical models based on bulk soil solution chemistry may fit field data, we argue that biological processes make an important contribution to mineral weathering and that a more detailed mechanistic understanding of these must be developed in order to predict responses to environmental changes and anthropogenic impact. © 2010 The British Mycological Society.
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| 48. |
- Flecknoe-Brown, Konrad Wilkens, et al.
(författare)
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Experimental and numerical investigation on fire behaviour of foam/fabric composites
- 2017
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Ingår i: 15th International Conference and Exhibition on Fire and Materials 2017. - 9781510846746 ; 1, s. 240-253
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Konferensbidrag (refereegranskat)abstract
- Upholstered furniture is a major contributor to the fuel load in a fire compartment. Modelling the fire behaviour of upholstered furniture would support performance based fire safety engineering, by allowing the specification of realistic fire scenarios. Modelling upholstered furniture composites in cone calorimeter test conditions is undertaken to validate fundamental assumptions about the fire behaviour of these combinations, without including complexities of a real sized system (e.g. constructional details of mattresses or sofas). Kinetic parameters were taken from micro combustion calorimeter tests and thermal properties were taken from literature and optimised using individual material cone calorimeter tests. A novel methodology of sample preparation was proposed for the cone calorimeter tests in an attempt to increase the one dimensionality of heat transfer. Modelling showed mixed results when compared with experiments. The results also indicated the models incapacity to capture material-material interactions, such as melting of polyester on the top of flexible polyurethane slab or shielding created by cotton residue to protect flexible polyurethane slab from heat exposure.
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| 49. |
- Flecknoe-Brown, Konrad Wilkens, et al.
(författare)
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Obtaining additional smoke characteristics using multi-wavelength light transmission measurements
- 2015
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Ingår i: Fire and Materials 2015 - 14th International Conference and Exhibition, Proceedings. ; , s. 136-148
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Konferensbidrag (refereegranskat)abstract
- The characteristics of smoke are highly dependent on the materials undergoing thermal decomposition and the environment in which this decomposition takes place. With the rising complexity in dedicated fire simulation tools, there is a need for increased information on the composition and properties of smoke in order to develop/validate and extend the fire safety engineering community's smoke and visibility prediction capabilities. Today, the most common method for the measurement of smoke production potential used in standardized material/product testing comprises of an optical system that measures the attenuation of a light source, by the smoke, over a known path-length. Based on this measurement, properties related to the overall smoke production potential of a material/product can be derived which are then used for material/product safety classifications. The downside to this method, although dynamic and robust, is that it provides only a measure of the amount of smoke being produced; it does not give any further information about additional characteristics of the measured smoke such as particle sizes. In this study, a method based on differences in the scattering and absorption by smoke of various wavelengths of light is examined. This methodology, which requires both a specific experimental approach and theoretical calculations, may potentially provide supplementary smoke characteristics in addition to smoke production measurements. A numerical optimisation routine is developed using Mie scattering theory that aims, in conjunction with experimental data, to provide estimates of mean smoke particle sizes and particle refractive index; which describes how a particle scatters and absorbs incoming light, both useful parameters for detailed smoke and visibility simulations. Initial numerical results give promising indications for the applicability of the method. The specific design requirements for an experimental methodology requiring the implementation of optical transmission measurements at a number of different wavelength light sources are also discussed, with conclusions, future work and recommendations given.
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| 50. |
- Fujii, Kazumichi, et al.
(författare)
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Biodegradation of low molecular weight organic compounds and their contribution to heterotrophic soil respiration in three Japanese forest soils
- 2010
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Ingår i: Plant and Soil. - : Springer Science and Business Media LLC. - 0032-079X .- 1573-5036. ; 334:1-2, s. 475-489
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Tidskriftsartikel (refereegranskat)abstract
- Low molecular weight (LMW) organic compounds in soil solution could be important substrates for heterotrophic soil respiration. The importance of LMW organic compound mineralization in heterotrophic soil respiration needs to be confirmed for different types of soils. The concentrations of LMW organic compounds in soil solution and mineralization kinetics of C-14-radiolabelled glucose, acetate, oxalate and citrate were studied in three Japanese forest soils (Andisol, Spodosol and Inceptisol) with varying adsorption capacities. Based on those results, the fluxes of LMW organic compound mineralization and their magnitude relative to heterotrophic soil respiration were quantified. Monosaccharides and organic acids comprised on average 5.9-11.2% and 0.9-1.4% of dissolved organic carbon in soil solution, respectively. Monosaccharide mineralization make up 49-74% of heterotrophic (basal) soil respiration at the soil-profile scale, while organic acid mineralization accounts for between 5% (Andisol) and 47-58% (Spodosol and Inceptisol) of heterotrophic soil respiration. The mineralization of LMW organic compounds is a substantial fraction of heterotrophic soil respiration regardless of soil type, owing to their rapid and continuous production and consumption. The specific contribution of organic acid mineralization to heterotrophic soil respiration varies depending on soil adsorption capacities, namely iron and aluminum oxides.
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