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  • 701.
    Öberg, Tomas
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Prediction of gas chromatographic separation for PBDE congeners from molecular descriptors2004Inngår i: The ESS Bulletin, ISSN 1651-5382, Vol. 2, nr 1, s. 74-90Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Polybrominated diphenyl ethers (PBDE) have been identified as environmental contaminants with a widespread distribution. The separation properties of PBDEs in high-resolution gas chromatography (HRGC) are important both for environmental analysis and for determining physical properties such as the vapour pressures. This study reports a quantitative structure-property relationship (QSPR), established between relative retention times on capillary HRGC and two constitutional structure descriptors that can perform equally well as more elaborate approaches. The simplified approach is recommended for explanatory models, while a more in-depth multivariate characterisation is suggested to assure similarity in applying prediction models.

  • 702.
    Öberg, Tomas
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Prediction of physical properties for PCB congeners from molecular descriptors2001Inngår i: Internet Journal of Chemistry, Vol. 4, nr 11Artikkel i tidsskrift (Fagfellevurdert)
  • 703.
    Öberg, Tomas
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Prediction of vapour pressures for halogenated diphenyl ether congeners from molecular descriptors2002Inngår i: Environmental Science and Pollution Research, ISSN 0944-1344, Vol. 9, nr 6, s. 405-411Artikkel i tidsskrift (Fagfellevurdert)
  • 704.
    Öberg, Tomas
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Probabilistisk riskbedömning fas 1.: Sannolikhetsbaserad uppskattning av miljö- och hälsorisker i förorenade markområden – en litteraturöversikt.2006Rapport (Annet vitenskapelig)
    Abstract [sv]

    Förorenad mark medför risker för hälsa och miljö. Litteraturöversikten redovisar hur nuvarande metodik för kvantitativa riskbedömningar kan kompletteras med en sannolikhetsbaserad – probabilistisk – ansats. Den probabilistiska metoden innebär att variabilitet (naturlig variation) och osäkerhet (okunskap) kan karakteriseras och därmed erhålls både ett bättre beslutsunderlag och kunskap om hur bedömningen ytterligare kan förfinas. Den probabilistiska metodiken har fått stor användning i USA och nu börjar den även tillämpas i flera europeiska länder.

    Probabilistiska riskbedömningar baseras i allmänhet på simuleringar av utfall från ett stort antal möjliga val av värden för ingångsvariabler och modellparametrar. Beräkningarna kan numer utföras med en vanlig persondator, men kräver en grundläggande kunskap om både teknikens möjligheter och begränsningar.

    Förorenad mark är vid sidan av kärnkraftsindustrin den viktigaste miljötillämpningen av probabilistisk riskbedömning och ett stort antal studier har publicerats för specifika objekt i Nordamerika, Europa och Asien. De avser exempelvis förorening med bly, arsenik, krom, uran, PCB, PAH, hexaklorbensen, pentaklorfenol, dioxiner och klorerade lösningsmedel. Dessa probabilistiska riskbedömningar täcker in olika exponeringssituationer inom vitt skilda verksamheter, däribland tidigare metallurgisk industri (smältverk och gruvor), tillverkningsindustri, gasverkstomter, träimpregnering, infrastruktur och deponier.

    En övergång till probabilistisk riskbedömning ställer krav på kvalitetssäkring, både avseende arbetsgången och redovisningsrutinerna. Det amerikanska naturvårdsverket (U. S. EPA) har gett ut relativt detaljerade anvisningar som i stort överensstämmer med vad som idag utgör vetenskapligt konsensus. Liknande behov av riktlinjer finns även i Europa.

    Behovet av att karakterisera variabilitet, osäkerhet och känslighet i riskbedömningsmodeller är inte annorlunda i Sverige än i Nordamerika. Dessutom behöver säkerhetsmarginalernas storlek klart kunna anges. Probabilistisk metodik kan enkelt integreras med nuvarande svenska riskbedömningsmodeller och rapporten redovisar ett beräkningsexempel för benso[a]pyren.

    Probabilistisk riskbedömning har ofta använts för att etablera platsspecifika riktvärden och det är här som en framtida användning i Sverige främst kan förutses. Rapporten pekar på behovet av ramar för att underlätta tolkning och jämförbarhet och rekommenderar att ett vägledningsdokument utarbetas. Likaså krävs utbildningsinsatser. Kurser i probabilistiska metoder finns i det ordinarie utbildningsprogrammet vid ett par högskolor, men ett behov finns även av kurser för fortbildning av redan yrkesverksamma, både som distansutbildning och kortare problembaserade kurser.

  • 705.
    Öberg, Tomas
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Production of halogenated aromatics from waste incineration – indicator parameters and operational control1987Inngår i: Proceedings från Swedish Flame Days, Studsvik, 8-9 september, 1987, 1987Konferansepaper (Annet vitenskapelig)
  • 706.
    Öberg, Tomas
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Replacement of PCBs (polychlorinated biphenyls) and HCB (hexachlorobenzene): the Swedish experience1996Inngår i: Alternatives to persistent organic pollutants: the Swedish input to the IFCS expert meeting on persistent organic pollutants in Manila, the Philippines, 17-19 June 1996, Solna: Kemikalieinspektionen , 1996Kapittel i bok, del av antologi (Annet vitenskapelig)
    Abstract [en]

    The total import to Sweden of PCB between 1957-1980 has been estimated to 8,000-10,000 metric tonnes. A substantial part of the import, probably more than 50% was re-exported in goods. The use of PCB in Sweden has been restricted since 1972, and in 1978 it was decided that no new permits to use PCB in new products should be issued. Remaining part in the power sector of the industry has also been removed. Transformers or capacitors containing PCB and with a higher rating than two kilovoltamperes (reactive) may not be used after the 31st of December 1994.

    PCB containing transformers were never manufactured in Sweden. The problem with PCB filled transformers and contaminated transformer oils has therefore been less severe, compared to many other industrialized countries. The main chemical alternative to PCB in transformers is mineral oil with different additives.

    PCB was used in the manufacture of capacitors in Sweden before 1978. The use for this purpose accounted for about 80% of the import of PCB. Chemical alternatives for PCB as capacitor fluid include a multitude of chemical compounds. The capacitor fluid most frequently used today in Sweden is a mixture of methyl(phenylmethyl)benzene and methylbis(phenylmethyl)benzene.

    PCB was used in different building materials as a plasticiser. Chemical alternatives include chlorinated paraffins and phthalates. Chlorinated paraffins are however replaced due to environ-mental concerns, and it has also been decided to phase out the phthalates. Substantial amounts of PCB, an estimated 190-650 metric tonnes, still remain in buildings. It is obvious that measures to deal with these problems may cost many times more than the replacement already accomplished.

    Destruction capability and capacity are keys to a successful and final solution to the PCB problem. The destruction cost is also the major cost factor in the replacement. 17,667 metric tonnes of PCB containing waste was received by SAKAB, the Swedish hazardous waste treatment plant, between 1987-1995. This gives an idea of how much PCB wastes that have to be handled.

    Minor amounts of HCB (hexachlorobenzene) has been used in some parts of the Swedish industry. HCB has not been manufactured in Sweden and previous use has been replaced. Estimates of the international production are contradictory. It therefore seems premature to neglect HCB as an organic micro-pollutant of environmental concern.

  • 707.
    Öberg, Tomas
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Socio-economic analysis in the REACH regulation: Impact assessment to support risk management2014Konferansepaper (Annet vitenskapelig)
  • 708.
    Öberg, Tomas
    European Chemicals Agency (ECHA), Helsinki, Finland.
    Substitution of chemicals based on assessment of hazard, risk and impact2014Inngår i: Journal of Risk Research, ISSN 1366-9877, E-ISSN 1466-4461, Vol. 17, nr 5, s. 565-568Artikkel i tidsskrift (Annet vitenskapelig)
  • 709.
    Öberg, Tomas
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Under strecket: Gruvinspektören som uppfann naturen2016Inngår i: Svenska Dagbladet, Kulturdelen, nr 18 oktober, s. 24-24Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
  • 710.
    Öberg, Tomas
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Validering av prediktionsmodeller för NOx-mätning1996Rapport (Annet vitenskapelig)
    Abstract [sv]

    Indirekt bestämning NOx-utsläpp med hjälp av prediktionsmodeller kan godtas för bestämning av miljöavgift. Kraven på tillförlitlighet förutsätts bli likartade som för mätutrustningar. Rapporten redovisar hur prediktionsmodeller bör utformas för att motsvara dessa krav.

    Ett stort antal anläggningar i USA använder redan nu prediktionsmodeller för att bestämma utsläppet av kväveoxider. De förslag till valideringskrav som har föreslagits är likartade som för mätutrustningar. Modellen skall upprättas utifrån mätdata från jämförande mätningar där olika driftsinställningar provas. Verifieringen genomförs likartat, med ett specificerat prestandakrav för precision och riktighet.

    I Sverige är detaljerade kvalitetskrav för prediktionsmodeller ännu inte fastställda. Följande punkter måste dock beaktas:

    - Ingångsdata för modelluppbyggnad.

    - Modellverifiering - rekalibrering.

    - Prestanda och definition av kalibreringsområde.

    - Kontroll av giltighet och signalvalidering.

    En genomgång av resultat från två genomförda projekt visar att indirekt bestämning av kväveoxider är tekniskt möjlig.

    Rapporten avslutas med ett förslag till "översättning" av Naturvårdsverkets nuvarande prestandakrav för mätinstrument. Det viktigaste prestandakraven för prediktionsmodellerna vid jämförande mätningar är att den systematiska skillnaden liksom standardavvikelsen högst får uppgå till 10% av kalibreringsområdet och högst 10 ppm tg.

  • 711.
    Öberg, Tomas
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Virtual screening for environmental pollutants: structure-activity relationships applied to a database of industrial chemicals2006Inngår i: Environmental Toxicology and Chemistry, ISSN 0730-7268, E-ISSN 1552-8618, Vol. 25, nr 4, s. 1178-1183Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The current risk paradigm calls for individual consideration and evaluation of each separate environmental pollutant, but this does not reflect accurately the cumulative impact of anthropogenic chemicals. In the present study, previously validated structure-activity relationships were used to estimate simultaneously the baseline toxicity and atmospheric persistence of approximately 50,000 compounds. The results from this virtual screening indicate fairly stable statistical distributions among small anthropogenic compounds. The baseline toxicity was not changed much by halogen substitution, but a distinct increase seemed to occur in the environmental persistence with increased halogenation. The ratio of the atmospheric half-lives to the median lethal concentrations provides a continuous scale with which to rank and summarize the incremental environmental impacts in a mixture-exposure situation. Halogenated compounds as a group obtained a high ranking in this data set, with well-known pollutants at the very top: DDT metabolites and derivatives, polychlorinated biphenyls, diphenyl ethers and dibenzofurans, chlorinated paraffins, chlorinated benzenes and derivatives, hydrochlorofluorocarbons, and dichlorononylphenol. Environmentally friendly chemicals that obtained the lowest rank are nearly all hydroxylated and water-soluble. Virtual screening can assist with "green chemistry" in designing safe and degradable products and enable assessment of the efficiency in chemicals risk management.

  • 712.
    Öberg, Tomas
    et al.
    Studsvik AB, Nyköping 61182, Sverige.
    Aittola, Jussi-Pekka
    Bergström, Jan
    Chlorinated aromatics from the combustion of hazardous waste1985Inngår i: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 14, nr 2, s. 215-221Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The production and emission of chlorinated aromatics from a hazardous waste incinerator were shown to be influenced by the operating conditions. The emissions of chlorinated benzenes, PCDD and PCDF show statistically significant correlations to the chlorine input. Different substance groups also correlate, and the results presented correspond well with a general formation mechanism of chlorophenols via chlorobenzenes as indicated by others.

  • 713.
    Öberg, Tomas
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Allhammar, Göran
    Chlorinated aromatics from metallurgical industries: Process factors influencing production and emissions1989Inngår i: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 19, nr 1-6, s. 711-716Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The emission and production of chlorinated aromatics from metallurgical industries, e g scrap-metal re-melting, show substantial variations due to a number of process factors. The data evaluated indicates clearly that the production of chlorinated aromatics is combustion controlled.

  • 714.
    Öberg, Tomas
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Bergbäck, Bo
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    A review of probabilistic risk assessment of contaminated land2005Inngår i: Journal of Soils and Sediments, ISSN 1439-0108, E-ISSN 1614-7480, Vol. 5, nr 4, s. 213-224Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background, Aims and Scope. The management and decisions concerning restoration of contaminated land often require in-depth risk analyses. An environmental risk assessment is generally described as proceeding in four separate steps: hazard identification, dose-response assessment, exposure assessment, and risk characterization. The risk assessment should acknowledge and quantify the uncertainty in risk predictions. This can be achieved by applying probabilistic methods which, although they have been available for many years, are still not generally used. Risk assessment of contaminated land is an area where probabilistic methods have proved particularly useful. Many reports have appeared in the literature, mostly by North American researchers. The aim of this review is to summarize the experience gained so far, provide a number of useful examples, and suggest what may be done to promote probabilistic methods in Europe and the rest of the world. Methods. The available literature has been explored through searches in the major scientific and technical databases, WWW resources, textbooks and direct contacts with active researchers. A calculation example was created using standard simulation software. Results and Discussion. Uncertainty and variability are part of every risk assessment. Much work on risks from contaminated soil has focussed on exposure, and choice and structure of the exposure model is then a basic uncertainty factor. Other factors, e.g. parameter uncertainty, are easier to characterize. Variability can be separated into inter-individual, spatial and temporal components. Both uncertainty and variability in the exposure variables can be investigated using Monte Carlo simulation methods. These simulations enable not only the estimation of the probability for a given risk or exposure, but also add information on the sensitivity of the various input variables. This will assist the assessor in further refining the risk analysis. The large number of applications published encompasses soil contamination by lead, arsenic, chromium, uranium, polychlorinated biphenyls (PCB), polycyclic aromatic hydrocarbons (PAH), hexachlorobenzene, pentachlorophenol and chlorinated solvents. Probabilistic risk assessments have been used in widely different settings, such as the metallurgical industry (mining and smelting operations), manufacturing, gas plants, wood impregnation, infrastructure, and waste landfills. Site-specific remediation goals can be specified using probabilistic methods, and a guideline document has been issued within the US Superfund programme. The usability of probabilistic risk assessment is illustrated by a calculation example. The current Swedish generic guideline value for benzo[a]pyrene in contaminated soil, with ingestion of vegetables as the major route of exposure, is compared with a probabilistic estimate. The toxicological reference value corresponds well with the upper 95th percentile of the estimated variability in intake, but does not account for uncertainty in the partition coefficients. Conclusions and Outlook. The probabilistic approach to risk assessment has proved its value in characterizing variability and uncertainty, and thereby contributing to a more informed and transparent decision-making process. The management of contaminated land is a major environmental application for probabilistic risk assessments. A substantial number of studies have been published and the method is now well established in the scientific community. This development has progressed further in the United States than elsewhere, but similar applications are now being reported from Europe and Asia. Probabilistic risk assessment is used to derive soil guideline values in the United Kingdom, and other countries may be anticipated to follow. However, efficient use of probabilistic methods for risk assessment of contaminated land requires certain components. There is a requirement for quality assurance and transparency that can be met by guidelines specifying data requirements and which items to report on. Both federal and state governments in the United States have issued such guidelines, and we see a similar need from a European perspective. A second component, necessary for a successful implementation of probabilistic methods, is education. We have ourselves developed undergraduate curricula, but we also see a need for continuous education of risk assessors and decision makers. The third component required is case studies, showing how probabilistic risk assessment can be implemented successfully in the cleanup of contaminated land. Most published studies originate from the United States, so here too there is a need for the rest of the world to catch up. In addition to the three components mentioned, there is an obvious need to develop and improve methods and practice of risk communication.

  • 715.
    Öberg, Tomas
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Bergbäck, Bo
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Filipsson, Monika
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Catalytic effects by metal oxides on the formation and degradation of chlorinated aromatic compounds in fly ash.2008Inngår i: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 71, nr 6, s. 1135-43Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Polychlorinated benzenes, dibenzo-p-dioxins (PCDD), and dibenzofurans (PCDF) may be formed below the combustion temperature in fly ash from municipal solid waste incinerators (MSWI). Copper catalyzes this formation, possibly by the Deacon reaction. Many other elements are also Deacon catalysts or promoters, and here we report results from a statistically designed experiment with 15 metal oxides added to fly ash and heated at 300 degrees C for 2h in an air atmosphere. A resolution IV fractional factorial design with four replicates was completed in 36 runs with the oxides of magnesium, yttrium, titanium, vanadium, niobium, chromium, molybdenum, tungsten, manganese, iron, cobalt, nickel, copper, zinc, and tin. All samples were analyzed for chlorinated benzenes and the results were evaluated by analysis of variance. The addition of copper significantly increased the amounts of the chlorinated benzenes, while cobalt, chromium and vanadium decreased the net formation. The oxides of zinc and iron seemed to have a slightly positive and negative effect respectively. The findings in this study seem to corroborate our previously reported results regarding the different catalytic effects of copper and chromium, and lack of a significant effect by nickel. Besides chromium, it also identifies cobalt and vanadium as potent catalysts for oxidative degradation of the chlorinated aromatic compounds found in MSWI fly ash.

  • 716.
    Öberg, Tomas
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Bergbäck, Bo
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Öberg, Erik
    Different catalytic effects by copper and chromium on the formation and degradation of chlorinated aromatic compounds in fly ash.2007Inngår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 41, nr 10, s. 3741-3746Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Fly ash from municipal solid waste incineration may catalytically enhance the formation and degradation of chlorinated aromatic compounds. The activities of three Deacon catalysts in this process were investigated in a statistically designed experiment. Chlorides of copper, chromium, and nickel were added to fly ash samples and the resulting samples heated at 300 degrees C for 2 h in an air atmosphere. The addition of copper increases the formation of all chlorinated aromatic compounds except the low chlorinated congeners of polychlorinated dibenzo-p-dioxins and dibenzofurans. The addition of chromium decreased the formation of most chlorinated aromatic compounds except the highest chlorinated species, where it was without effect. The addition of nickel did not show any significant effect. The outcome of the experiment can be interpreted as two competing processes: the chlorination of aromatic rings and the oxidation of carbon-carbon and carbon-oxygen bonds. The delicate balance between chlorination and oxidation could probably be further exploited to minimize both the emissions and the net production of chlorinated aromatic compounds from combustion.

  • 717.
    Öberg, Tomas
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Bergström, Jan
    Combustion test data from a Swedish hazardous waste incinerator1986Inngår i: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 15, nr 9-12, s. 2045-2048Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Here we present results from our tests with PCB-incineration at the SAKAB hazardous waste incinerator in Norrtorp, Sweden. Combustion tests were made with PCB both as a fluid (Arochlor 1242) and as a contaminant of solid waste (Arochlor 1016 in capacitors). A general conclusion was that the incineration of considerable amounts of PCB did not effect the production of PCDD and PCDF in this combustion plant.

  • 718.
    Öberg, Tomas
    et al.
    STUDSVIK AB, S-61182 NYKOPING, SWEDEN .
    Bergström, Jan
    Dioxins from Scandinavian waste combustion plants1986Inngår i: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 15, nr 9-12, s. 2041-2044Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A large quantity of emission data for PCDD and PCDF have been reported to date. Less information is available concerning the controlling parameters for the production of chlorinated aromatics from waste combustion. Here we report results and conclusions from investigations carried out in the Scandinavian countries to date.

  • 719.
    Öberg, Tomas
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Bergström, Jan
    Emission and chlorination pattern of PCDD/PCDF predicted from indicator parameters1987Inngår i: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 16, nr 6, s. 1221-1230Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The emission and chlorination pattern of polychlorinated dioxins and dibenzofurans from waste combustion shows a close covariation with that of chlorinated benzenes and phenols. This covariation can be utilized to predict the emission levels of specific isomers as well as the pattern of congeners.

  • 720.
    Öberg, Tomas
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Bergström, Jan
    Halogenated aromatics from waste incineration – indicator parameters1987Inngår i: American Flame Research Committee, 1987Konferansepaper (Annet vitenskapelig)
  • 721.
    Öberg, Tomas
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Bergström, Jan
    Hexachlorobenzene as an indicator of dioxin production from combustion1985Inngår i: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 14, nr 8, s. 1081-1086Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The production of polychlorinated dioxins and dibenzofurans shows a strong correlation with the production of hexachlorobenzene. Hexachlorobenzene can be used as an indicator for the production of chlorinated aromatics.

  • 722.
    Öberg, Tomas
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Bergström, Jan
    Indicator Parameters for PCDD/PCDF1989Inngår i: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 19, nr 1-6, s. 337-344Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Relations between different chlorinated aromatics have been evaluated in 66 samples from various industrial activities. For municipal waste combustion partial least squares modelling with latent variables (PLS) can explain 86 % of the variance in PCDD/PCDF from the isomerspecific analytical data for chlorinated benzenes and phenols.

  • 723.
    Öberg, Tomas
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Bergström, Jan
    Indicator parameters for PCDD/PCDF: plant specific models1992Inngår i: Organohalogen Compounds, ISSN 1026-4892, Vol. 8, s. 197-200Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Previously presented results have shown that the emissions of PCDD/PCDF can be modelled and predicted from less costly and more precise isomerspecific analyses of different chlorinated benzenes and phenols. The new results we report here comes from a study aimed to further utilize these possibilities and develop specific models for each plant to accomplish maximum precision and accuracy in the calibration process. Plant specific models have been developed for two municipal waste combustion (MWC) facilities and one metallurgic industry.

  • 724.
    Öberg, Tomas
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Bergström, Jan
    Organiska mikroföroreningar från stålverk1988Rapport (Annet vitenskapelig)
    Abstract [sv]

    Miljökonsulterna har på uppdrag av Jernkontoret värderat mätningarna av organiska mikroföroreningar från nio svenska stålverk utförda under tiden 1985 till och med 1987.

    Mätningarna utgör enbart kortvariga stickprov. Så finns t ex utsläppet till luft av polycykliska aromatiska kolväten, PAH, endast dokumenterade med 13 analyserade prov. För TCDD-ekvivalenter är antalet redovisade prov 18 stycken. Intervallet mellan de högsta och lägsta uppmätta utsläppen är för PAH 8 till 920 mg/ton stål och för TCDD-ekivalenter <0.3 till 9 µg/ton. Det är därför inte möjligt att ur mätresultaten beräkna ett realistiskt värde för normalutsläpp från stålverken idag.

    Det föreligger en tydlig samvariation av mängden PAH och klorerade aromater i utsläppet från de olika stålverken. Det är därför rimligt att utgå från att bildning och destruktion av föroreningarna är i huvudsak förbränningsstyrda förlopp. Mätresultaten styrker därmed att utsläppen kan minimeras genom relativt enkla insatser för att höja oxidationsnivån genom efterförbränning av processgaserna.

  • 725.
    Öberg, Tomas
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Darnerud, Per-Ola
    Hajslova, Jana
    Miljögifter i fisk 2001/2002: Vänern och Vättern.2003Rapport (Annet vitenskapelig)
    Abstract [sv]

    Vätternvårdsförbundet och Vänerns vattenvårdsförbund har genomfört en undersökning av miljögifter i fisk som omfattar 38 kemiska ämnen och ämnesgrupper samt "dioxiner" (PCDD/PCDF) och PCB (polyklorerade bifenyler). I undersökningen ingår dels ämnen från den normala livsmedelskontrollen, dels de ämnen som anges i EUs vattendirektiv. Analyserna av "EU-ämnena" har genomförts med stöd från Naturvårdsverket som är delfinansiär av projektet. De fiskarter som har undersökts är lax (Vänern), öring, röding (Vättern) och lake. Undersökningen ger därmed en relativt heltäckande bild av föroreningssituationen vad gäller fisk i Sveriges två största insjöar.

    Analyserna av samlingsprov har utförts av Livsmedelsverket, Umeå universitet och ALcontrol AB. De flesta av de analyserade föroreningarna saknades helt i fiskproven. När det gäller allmänna miljöföroreningar så är det främst mjukgörare, ytaktiva ämnen och några enkla lösningsmedel som har detekterats. Däremot saknas spår av de flesta avvecklade och nu godkända icke-klorerade bekämpningsmedel, dock med tennorganiska föreningar som ett viktigt undantag.. Samma iakttagelse är även giltig för icke-klorerade polycykliska aromatiska kolväten (PAH). Av redovisning framgår att det främst är långlivade klororganiska föreningar som kan påvisas hos de flesta fiskarterna.

    En tydlig minskning av klororganiska föreningarna skedde under 1970- och början av 1980-talet. Sedan dess har nivåerna legat relativt stabila. Kvicksilver, PCDD/PCDF och dioxinlika PCB är de ämnesgrupper som ligger högst i relation till de nivåer som har angetts som tolerabla från ett folkhälsoperspektiv. Det finns därför skäl att koncentrera undersökningsinsatserna till dessa grupper av miljöföroreningar. Klart är dock att medelhalten av PCDD/PCDF i fet fisk från Vänern och Vättern ligger under EUs nuvarande gränsvärde på 4 pg/g färskvikt.

    Långlivade klorerade miljögifter fortsätter alltså att vara ett bekymmer, men när de gäller bekämpningsmedel så är det inte längre ett nationellt problem. Den statistiska utvärderingen av föroreningsmönstret tyder på att både klorerade bekämpningsmedelsrester och PCB kan härröra från långväga transport eller från någon typ av "depåer" (ifrån tidigare utsläpp och användning). Däremot samvarierar PCDD, PCDF och hexaklorbensen inbördes, men endast i begränsad utsträckning med de övriga miljöföroreningarna. Då alla tre substansgrupperna kan bildas i högtemperaturprocesser så är det inte en orimlig hypotes att dessa föroreningar främst har sitt ursprung i närområdet.

  • 726.
    Öberg, Tomas
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Deming, Stanley. N.
    Find optimum operating conditions fast2000Inngår i: Chemical engineering progress, ISSN 0360-7275, E-ISSN 1945-0710, Vol. 96, nr 4, s. 53-59Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In today's world of intense financial competition, chemical processes must be optimized quickly if they are to become successful. These successful processes must continue to be operated optimally if they are to retain their competitive edge. In this article, we discuss statistically-based optimization strategies that can be used to achieve these two goals of achieving and maintaining optimized processes.

  • 727.
    Öberg, Tomas
    et al.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Iqbal, Muhammad Sarfraz
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    The chemical and environmental property space of REACH chemicals2012Inngår i: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 87, nr 8, s. 975-981Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The European regulation on chemicals, REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals), came into force on 1 June 2007. With pre-registration complete in 2008, data for these substances may provide an overview of the expected chemical space and its characteristics. In this paper, using various in silico computation tools, we evaluate 48782 neutral organic compounds from the list to identify hazardous and safe compounds. Two different classification schemes (modified Verhaar and ECOSAR) identified between 17% and 25% of the compounds as expressing only baseline toxicity (narcosis). A smaller portion could be identified as reactive (19%) or specifically acting (2.7%), while the majority were non-assigned (61%). Overall environmental persistence, bioaccumulation and long-range transport potential were evaluated using structure-activity relationships and a multimedia fugacity-based model. A surprisingly high proportion of compounds (20%), mainly aromatic and halogenated, had a very high estimated persistence (> 195 d). The proportion of compounds with a very high estimated bioconcentration or bioaccumulation factor (> 5000) was substantially less (6.9%). Finally, a list was compiled of those compounds within the applicability domain of the models used, meeting both persistence and bioaccumulation criteria, and with a long-range transport potential comparable to PCB. This list of 68 potential persistent organic pollutants contained many well-known compounds (all halogenated), but notably also five fluorinated compounds that were not included in the EINECS inventory. This study demonstrates the usability of in silico tools for identification of potentially environmentally hazardous chemicals.

  • 728.
    Öberg, Tomas
    et al.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Iqbal, Muhammad Sarfraz
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    The REACH space of organic chemistry and hazard properties.2011Inngår i: Presentation vid 6th International Symposium on Computational Methods in Toxicology and Pharmacology Integrating Internet Resources (CMTPI-2011) i Maribor, 3-7 september, 2011., 2011Konferansepaper (Annet vitenskapelig)
  • 729.
    Öberg, Tomas
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Liu, Tao
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Global and local PLS regression models to predict vapor pressure2008Inngår i: QSAR & combinatorial science (Print), ISSN 1611-020X, E-ISSN 1611-0218, Vol. 27, nr 3, s. 273-279Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The vapor pressure is a key property in determining the distribution and fate of environmentally relevant compounds, but experimental determinations are only available for alimited number of the chemicals in current commercial use. Despite experimental efforts there is a need for estimation methods. The liquid or subcooled liquid vapor pressures at 298.15 K were collected from the literature for a diverse set of 1340 organic compounds. Theoretical molecular descriptors were derived after optimization to low-energy conformations and used to investigate the performance of global and local Quantitative Structure – Property Relationships (QSPR). A global PLSR model with ten latent variables was found to be optimal. The predictive performance of this model, within the domain of applicability, was estimated at n=420, Q2Ext0.980, and RMSEP=0.410 (log Pa). This model can be used in conjunction with other estimation models to assess the potential for a long range atmospheric transport.

     

  • 730.
    Öberg, Tomas
    et al.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Liu, Tao
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Updating existing QSAR models: selection and weighting of new data2010Inngår i: Journal of Cheminformatics, ISSN 1758-2946, E-ISSN 1758-2946, Vol. 2, nr Suppl 1, s. P19-Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    Computational chemistry and quantitative structure-activity relationships (QSAR) are foreseen to be extensively used in the implementation of the new REACH regulation for chemicals in Europe. However, for some compound groups the data are too few in number to permit both calibration and testing of a new model. Usage and previously developed or updated models are then viable alternatives.Perfluorocarboxylic acids (PFCAs) and fluoroteleomer alcohols (FTOHs) are two groups of environmentally relevant compounds, with unique physical and chemical properties. The subcooled liquid vapour pressure (pL) is one such property, where experimental determinations are limited and far from consistent [1]. Updating is, however, challenging when the new compounds are far outside of the original calibration domain space. But by carefully selecting and weighting only three new compounds, we have been able to update a previously developed general QSAR model [2], to cover the new domain while maintaining predictive performance for the earlier calibration and test data. The optimal weighting scheme was determined from the sample leverages and residuals in the calibration phase [3].The performance of this re-calibrated model greatly surpassed previous modelling attempts [4], when applied to an external test set of two PFCAs and four FTOHs with pL in the range 0.2-200 Pa; with Q2Ext = 0.994 and RMSEP = 0.190 units of log Pa. The domain coverage also increased from 1% to 51%, for 426 perfluoroalkylated compounds selected from the REACH registration list, the PhysProp database, and the OECD 2006 survey [5]. Selection and weighting of new calibration data can thus facilitate the extension and use of existing QSAR models. This investigation was supported by the EU FP7 project CADASTER (grant agreement no. 212668).

  • 731.
    Öberg, Tomas
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Neuer-Etscheidt, Katja
    Nordsieck, Hermann
    Zimmermann, Ralf
    Dioxin surrogates: a comparison of approaches2002Inngår i: Organohalogen Compounds, ISSN 1026-4892, Vol. 59, s. 37-44Artikkel i tidsskrift (Fagfellevurdert)
  • 732.
    Öberg, Tomas
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Peltola, Pasi
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Increased deposition of polychlorinated biphenyls (PCBs) under an AC high voltage power line2009Inngår i: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 43, nr 39, s. 6168-6174Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    There is considerable public concern regarding the potential risks to health of electromagnetic fields in general and high-voltage power lines in particular. As epidemiological findings are not supported by a clearly defined mechanism of direct magnetic field interactions with the human body, potential indirect effects are of interest. It has been suggested that an increased exposure to chemical pollutants could occur near high-voltage power lines due to formation and deposition of charged aerosols. The current study reports empirical evidence that seems to support this hypothesis. The deposition of 18 congeners of polychlorinated biphenyls (PCBs) was studied by collecting samples of pine needles under a 400 kV AC power line and at reference sites in the vicinity. Compared to the reference sites, the average deposition of PCB congeners under the power line was almost double. This difference between the two groups of samples was statistically significant. While it is premature to draw any conclusions regarding the human exposure near high-voltage power lines, the issue deserves attention and further investigations

  • 733.
    Öberg, Tomas
    et al.
    ENVIRONM CONSULTANTS STUDSVIK, S-61182 NYKOPING, SWEDEN .
    Warman, Kristofer
    Bergström, Jan
    Brominated aromatics from combustion1987Inngår i: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 16, nr 10-12, s. 2451-2465Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The production of brominated aromatics from combustion was shown to be influenced by the operating conditions. Brominated aromatics also showed high yields compared to their chlorinated analogues.

  • 734.
    Öberg, Tomas
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Warman, Kristofer
    Bergström, Jan
    Bromine and waste incineration: an environmental risk?1990Inngår i: Organohalogen Compounds, ISSN 1026-4892, Vol. 2, s. 339-342Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Process factors influencing the production of brominated aromatics in waste incinerators are bromine load and combustion quality. Emission measurements do not indicate unacceptable environmental risks from controlled combustion and advanced flue gas cleaning.

  • 735.
    Öberg, Tomas
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Warman, Kristofer
    Bergström, Jan
    Distribution of toxic coplanar PCBs and PCDD/PCDF in pine needles from the Swedish environment: evaluation of data and source identification1990Inngår i: Organohalogen Compounds, ISSN 1026-4892, Vol. 1, s. 449-452Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Environmental samples from different areas of Sweden indicate a widespread contamination of toxic coplanar PCBs. Uncontrolled combustion (e.g. fires) is a likely source.

  • 736.
    Öberg, Tomas
    et al.
    Miljökonsulterna i Studsvik AB (Environmental Consultants).
    Warman, Kristofer
    Miljökonsulterna i Studsvik AB (Environmental Consultants).
    Bergström, Jan
    Miljökonsulterna i Studsvik AB (Environmental Consultants).
    Production of chlorinated aromatics in the post-combustion zone and boiler1989Inngår i: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 19, nr 1-6, s. 317-322Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The production of halogenated aromatics has been investigated in the SAKAB hazardous waste incinerator, Norrtorp, Sweden. The measurement results show that there is a substantial net production of chlorinated aromatics in the boiler.

  • 737.
    Öberg, Tomas
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Öhrström, T.
    Chlorinated aromatics from combustion: influence of chlorine, combustion conditions and catalytic activity2003Inngår i: Environmental Science & Technology, ISSN 0013-936X, Vol. 37, nr 17, s. 3995-4000Artikkel i tidsskrift (Fagfellevurdert)
  • 738.
    Öberg, Tomas
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Öhrström, Tomas
    Bergström & Öhrström.
    Bergström, Jan
    Bergström & Öhrström.
    Metal catalyzed formation of chlorinated aromatic compounds: a study of the correlation pattern in incinerator fly ash.2007Inngår i: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 67, nr 9, s. S185-S190Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Chlorinated aromatics are unintentionally formed and released from combustion and other thermal processes involving organic matter and chlorine. The catalytic activity of incinerator fly ash in the low-temperature formation of chlorinated aromatics has been demonstrated in both laboratory experiments and full-scale trials. Copper has been shown to be an effective catalyst, but several other transition metals possess a similar activity. Here results are reported from a series of full-scale combustion trials with different fractions of household and industrial wastes, with waste from forestry as a reference fuel. The composition of elements and chlorinated aromatics in the fly ash was evaluated with principal component analysis and partial least squares regression. The observed correlation pattern indicates that metals other than copper are of equal importance for the catalytic activity. Chromium and nickel are two of these metals, which may contribute to the de novo formation of chlorinated benzenes, phenols, PCDD and PCDF.

  • 739.
    Öberg, Tomas
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Öhrström, Tomas
    Bergström, Jan
    The correlation pattern of fly ash components: Chromium as a potential catalyst in the thermal formation of chlorinated aromatic compounds2004Inngår i: Environmental Chemistry, ISSN 1448-2517, E-ISSN 1449-8979, Vol. 1, nr 1, s. 18-21Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Chlorinated aromatic compounds are unintentionally released from combustion sources into the environment. This thermal formation is catalyzed by fly ash components and much interest has been focussed on the role of copper. This study report results from a series of 16 full-scale trials with different fuel compositions. The correlation pattern of fly ash components seem to suggest that the catalytic effect may be due also to other metal oxychlorination catalysts. Chromium shows particularly strong and statistically significant correlations with many of the chlorinated phenols, benzenes, dibenzo-p-dioxins (PCDDs), and dibenzofurans (PCDFs).

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