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Sökning: AMNE:(NATURAL SCIENCES Chemistry Environmental chemistry) > Övrigt vetenskapligt > Linköpings universitet

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1.
  • Chen, Weimin (författare)
  • Optically detected magnetic resonance of defects in semiconductors
  • 2013
  • Ingår i: EPR of Free Radicals in Solids II : Trends in Methods and Applications. - Dordrecht : Springer Netherlands. - 978-94-007-4886-6 - 978-94-007-4887-3 ; s. 345-366
  • Bokkapitel (övrigt vetenskapligt)abstract
    • EPR of Free Radicals in Solids: Trends in Methods and Applications, 2nd ed. presents a critical two volume review of the methods and applications of EPR (ESR) for the study of free radical processes in solids. Emphasis is on the progress made in the developments in EPR technology, in the application of sophisticated matrix isolation techniques and in the advancement in quantitative EPR that have occurred since the 1st edition was published. Improvements have been made also at theoretical level, with the development of methods based on first principles and their application to the calculation of magnetic properties as well as in spectral simulations. EPR of Free Radicals in Solids II focuses on the trends in applications of experimental and theoretical methods to extract structural and dynamical properties of radicals and spin probes in solid matrices by continuous wave (CW) and pulsed techniques in nine chapters written by experts in the field. It examines the studies involving radiation- and photo-induced inorganic and organic radicals in inert matrices, the high-spin molecules and metal-based molecular clusters as well as the radical pro-cesses in photosynthesis. Recent advancements in environmental applications in-cluding measurements by myon resonance of radicals on surfaces and by quantitative EPR in dosimetry are outlined and the applications of optical detection in material research with much increased sensitivity reviewed. The potential use of EPR in quantum computing is considered in a newly written chapter. This new edition is aimed to experimentalists and theoreticians in research involving free radicals, as well as for students of advanced courses in physical chemis-try, chemical physics, materials science, biophysics, biochemistry and related fields.
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  • Bergbäck, Bo, et al. (författare)
  • Metals in society
  • 1997
  • Ingår i: The global environment. - Oslo : Scandinavian Science Publ.. - 3-527-28771-X - 9783527287710 (Print) - 9783527619658 (Online) ; s. 276-289
  • Bokkapitel (övrigt vetenskapligt)abstract
    • These two volumes provide an authoritative overview of all the major environmental topics. Focusing on the current 'state of the art' as well as the examination of future perspectives. The first volume spotlights the basic sciences and environmental exploitation, exploring issues such as global climates, marine pollution, tourism and the environment, chemical time bombs and the ozone layer. The second volume is devoted to preventitive strategies, technology and management. Recommended techniques for environmental monitoring, waste management, responses to oil spills, ecological engineering are described, as are environmental education and international law. Volume 2 highlights strategies for solving 'man-made' environmental problems. This reference is addressed to scientists and engineers in industry and in academia, government planners and administrators, political scientists, lawyers and economists and promotes understanding between experts in various disciplines.
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8.
  • Björn, Annika, 1972- (författare)
  • Microbial Transformation of Organotin Compounds under Simulated Landfill Conditions
  • 2007
  • Doktorsavhandling (övrigt vetenskapligt)abstract
    • Mono- and di-alkyltins are used extensively as heat stabilizers for processing of poly vinyl chloride (PVC). Tin mercaptide stabilizers are some of the most effective PVC stabilizers available. The main applications for tin stabilizers are building/construction products, such as pipes, fittings, siding and profiles (windows etc.), packaging and flexible PVC plastics. Most PVC products have been and are subjected to landfilling, when their use is terminated. The structure of the polymer itself and the substances used as additives have been a concern for environmental authorities in many countries since long, which also includes their presence in landfills. In the case of the organotin stabilizers their leaching out from (PVC) plastics into the leachate phase of landfills with the risk for further transport to ground and surface waters is in focus.The main objectives of this thesis take their start in this background and, thus, included the elucidation of whether organotin compounds (OTs) in stabilized PVC products contribute to the pool of OTs observed in landfill leachates and if these compounds are degradable by the microorganisms developing under anaerobic landfill conditions.To reach these aims and the research questions raised the forwarded PVC materials were added to muniscipal solid waste (MSW) processed in containers used to simulate the ageing of landfills under forced conditions. These include traditional landfill simulation reactors (LSRs) at a scale of ca 100 L and also at a smaller scale ca 5 L constructed for the purpose of this study, i.e. the modular environmental test system (METS). The latter were used to investigate temperature effects on the possible release of OTs from different types of PVC materials. The capacity by microorganisms in landfill environments were used to investigate their capacity to degrade or transform organotin stabilizer compounds focused on in this thesis. Differences in this capacity in relation to the ageing of landfills and exposure to the alkyltin stabilizers were studied with microorganisms sampled from LSRs spiked with PVC over time and from landfill site.Access to sensitive and reliable equipment and analytical protocols for the analysis of OTs and their transformation intermediates and end products are prerequisites for this kind of studies. This necessitated an adoption and adaptation of analytical methods for the low concentrations occurring in the environment. Two methods were established and well served the requirements.Indeed OTs migrated out from especially flexible PVC materials, while rigid PVC was less prone for OT release as judged from the METS simulations. The METS studies showed that the OT release increase substantially at higher temperatures and especially so when the temperature was higher than the glass transition of the PVC.materials.The organotin stabilizers were transformed, partly or completely degraded, by anaerobic microorganisms derived from landfill environments. Upon prolonged exposure to OTs leaching from PVC in LSR simulations the microorganisms displayed a higher efficiency in degradation of the leached OTs. The microorganisms would methylate inorganic tin and metyltin present in the MSW material as well as perform dealkylation depending on the tin concentrations prevailing. During these studies it was discovered that the organotin stabilzers were inhibiting the methanogens and fermentative bacteria, which lead to a retardation of the anaerobic mineralisation of the MSW in the assays. An in depth study revealed that the OTs themselves but also their ligands and degradation products from these together effected the inhibition.However, given the extent of leaching in relation to the water flows in landfills, the concentrations will mainly be too low to pose any risks to the surrounding environment.
9.
  • Hörsing, Maritha, 1970-, et al. (författare)
  • Effects of Temperature and Landfill Ageing on leaching and Degradation of Phtalates from a Poly(vinyl chloride) Carpet under Simulated Landfill Conditions
  • ????
  • Annan publikation (övrigt vetenskapligt)abstract
    •  Phthalic ether esters are a group of chemicals used in the manufacture of PVC plastics, often as plasticizing additives, hence they may leach from the material and/or finished products before, during and after their use. This article presents results from laboratory-scale investigations of the fates of di-2-ethylhexyl phthalate (DEHP) and benzyl-butyl phthalate (BBP) under simulated landfill conditions, in custom-designed incubation units filled with model municipal solid waste. More specifically, the effects of temperature and landfill degradation phase on both the leaching and degradation potential of the two phthalates from a PVC carpet were examined, by measuring them in samples from units maintained at 20, 37, 55 and 70°C as they progressed through anaerobic acidogenic and methanogenic landfill phases. The results show that both BBP and DEHP leached from the carpet. For DEHP there was a clear temperature effect, and the highest losses were observed at 70°C, while for BBP slight increases in losses with temperature were observed from 20 to 55°C, and from 55 to 70°C, but the largest losses were seen at 37°C, probably due to biodegradation. Further degradation of the leached phthalates occured at all temperatures. Apparent degradation products observed included phthalic acid (PA) and mono (2-ethylhexyl)-, monobutyl- and monobenzyl-phthalate. In all cases the biological degradation of the phthalates occurred mainly after the systems switched to methanogenic conditions. The rate-limiting step of degradation in the 20 and 37°C units seemed to be the transformation of the monoesters, which tended to accumulate more than PA, while at 55 and 70°C PA accumulated to a higher extent.
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10.
  • Hörsing, Maritha, 1970-, et al. (författare)
  • Investigation of the transformation potential of some ether derivatives of tetrabromobisphenol A and dimethyl ether of bisphenol A under methanogenic conditions
  • ????
  • Annan publikation (övrigt vetenskapligt)abstract
    • This study focused on transformation of the flame retardant tetrabromobisphenol A (TBBPA) and ether derivatives thereof during incubation under methanogenic conditions using landfill waste as inoculum. Bisphenol A dimethyl ether was also investigated in that context. Glass wool was placed in the incubation flasks to increase the surface area for adsorption of target compounds and thereby maximize exposure to the microbial population. A uniform analytical protocol for extraction of the silica surface and the aqueous phase was developed to suit all the targets. Overall recoveries were lowest for the dimethylated ethers and highest for TBBPA-dihydroxyethylether. TBBPA decreased to below detection limit within 35 days, but neither BPA nor the methyl ether of TBBPA was confirmed as a transformation product. The dimethylated ethers of BPA and TBBPA disappeared within 14 and 51 days, respectively, and BPA, but not TBBPA, proved to be a transformation product. No losses were observed for the most hydrophobic target TBBPA-dibromopropyl ether during the time frame of the transformation study (i.e., 51 days).
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