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  • 1.
    Achu Nges, Ivo
    et al.
    Department of Biotechnology, Lund Univeristy.
    Björn, Annika
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Björnsson, Lovisa
    Department of Biotechnology, Lund University.
    Stable operation during pilot-scale anaerobic digestion of nutrient-supplemented maize/sugar beet silage2012In: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 118, p. 445-454Article in journal (Refereed)
    Abstract [en]

    Biogas production from maize/sugar beet silage was studied under mesophilic conditions in a continuous stirred tank reactor pilot-scale process. While energy crop mono-digestion is often performed with very long hydraulic retention times (HRTs), the present study demonstrated an efficient process operating with a 50-day HRT and a corrected total solids (TScorr) based organic loading rate of 3.4 kg/m3×d. The good performance was attributed to supplementation with both macro- and micronutrients and was evidenced by good methane yields (318 m3/ton TScorr) which were comparable to laboratory maximum expected yields plus low total volatile fatty acid concentrations (< 0.8 g/L). A viscoplastic and thixotropic digester fluid behaviour was observed, and the viscosity problems common in crop mono-digestion were not seen in this study. The effluent also complied with Swedish certification standards for bio-fertilizer for farmland application. Nutrient addition thus rendered a stable biogas process, while the effluent was a good quality bio-fertilizer.

  • 2.
    Ammenberg, Jonas
    et al.
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology. Linköping University, Biogas Research Center.
    Svensson, Bo
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Karlsson, Magnus
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Biogas Research Center.
    Svensson, Niclas
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology. Linköping University, Biogas Research Center.
    Björn, Annika
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Karlsson, Martin
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, The Institute of Technology. Linköping University, Biogas Research Center.
    Tonderski, Karin
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, The Institute of Technology. Linköping University, Biogas Research Center.
    Eklund, Mats
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology. Linköping University, Biogas Research Center.
    Biogas Research Center, BRC: Slutrapport för etapp 12015Report (Other academic)
    Abstract [en]

    Biogas Research Center (BRC) is a center of excellence in biogas research funded by the Swedish Energy Agency, Linköping University and a number of external organizations with one-third each. BRC has a very broad interdisciplinary approach, bringing together biogas-related skills from several areas to create interaction on many levels:

    • between industry, academia and society,
    • between different perspectives, and
    • between different disciplines and areas of expertise.

    BRC’s vision is:

    BRC contributes to the vision by advancing knowledge and technical development, as well as by facilitating development, innovation and business. Resource efficiency is central, improving existing processes and systems as well as establishing biogas solutions in new sectors and enabling use of new substrates.

    For BRC phase 1, the first two year period from 2012-2014, the research projects were organized in accordance with the table below showing important challenges for biogas producers and other stakeholders, and how these challenges were tackled in eight research projects. Five of the projects had an exploratory nature, meaning that they were broader, more future oriented and, for example, evaluated several different technology paths (EP1-5). Three projects focused more on technology and process development (DP6-8).

    This final report briefly presents the background and contains some information about competence centers in general. Thereafter follows more detailed information about BRC, for example, regarding the establishment, relevance, organization, vision, corner stones and development. The participating organizations are presented, both the research groups within Linköping University and the partners and members. Further on, there is a more detailed introduction to and description of the challenges mentioned in the table above and a short presentation from each of the research projects, followed by some sections dealing with fulfillment of objectives and an external assessment of BRC. Detailed, listed information is commonly provided in the appendices.

    Briefly, the fulfillment of objectives is good and it is very positive that so many scientific articles have been published (or are to be published) from the research projects and also within the wider center perspective. Clearly, extensive and relevant activities are ongoing within and around BRC. In phase 2 it essential to increase the share of very satisfied partners and members, where now half of them are satisfied and the other half is very satisfied. For this purpose, improved communication, interaction and project management are central. During 2015, at least two PhD theses are expected, to a large extent based on the research from BRC phase 1.

    In the beginning of 2014 an external assessment of BRC was carried out, with the main purpose to assess how well the center has been established and to review the conditions for a future, successful competence center. Generally, the outcome was very positive and the assessors concluded that BRC within a short period of time had been able to establish a well-functioning organization engaging a large share of the participants within relevant areas, and that most of the involved actors look upon BRC as a justifiable and well working investment that they plan to continue to support. The assessment also contributed with several relevant tips of improvements and to clarify challenges to address.

    This report is written in Swedish, but for each research project there will be reports and/or scientific papers published in English.

    The work presented in this report has been financed by the Swedish Energy Agency and the participating organizations.

  • 3.
    Björn, Annika
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Biodegradation of organotin stabilisers in landfills2000Conference paper (Other academic)
  • 4.
    Björn, Annika
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Leaching of Organotin Stabilizers from PVC under Prevailing Landfill Conditions2010In: Advances in Chemistry Research, Volyme 3 / [ed] James C. Tayler, New York: Nova Science Publishers, Inc , 2010, Volume 3Chapter in book (Other academic)
    Abstract [en]

    This book presents original research results on the leading edge of chemistry research. Each article has been carefully selected in an attempt to present substantial research results across a broad spectrum.

  • 5.
    Björn, Annika
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Microbial Transformation of Organotin Compounds under Simulated Landfill Conditions2007Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    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.

    List of papers
    1. Impacts of Temperature on the Leaching of Organotin Compounds From Poly(vinyl chloride) Plastics: A Study Conducted Under Simulated Landfill Conditions
    Open this publication in new window or tab >>Impacts of Temperature on the Leaching of Organotin Compounds From Poly(vinyl chloride) Plastics: A Study Conducted Under Simulated Landfill Conditions
    Show others...
    2007 (English)In: Journal of Vinyl and Additive Technology, ISSN 1083-5601, Vol. 13, no 4, p. 176-188Article in journal (Refereed) Published
    Abstract [en]

    The aim of the study was to investigate whether organotin-stabilized poly(vinyl chloride) (PVC) products could contribute to the pool of organotins observed in landfill leachates, and if the possible release could be related to different temperatures and landfill degradation phases. Small-scale anaerobic reactors filled with generic household waste, a mixture of inocula, and different PVC plastics were used in the study and incubated at 20, 37, 55, and 70°C. The reactor units incubated at temperatures of 20-55°C underwent the anaerobic degradation phases that are characteristic for the aging of landfilled waste material. There were, however, differences in the duration of the phases as well as in the total biogas production among the units. Under methanogenic conditions greater losses of organotin compounds were observed as compared to acidogenic conditions. It was shown that the release of organotin stabilizers increases considerably at temperatures above the glass transition of the PVC products. A dealkylation from di- into monoalkyltin species was observed, as well as a possible methylation of inorganic tin. However, the main part of the organotins was adsorbed into the solid waste matrix.

    National Category
    Environmental Sciences
    Identifiers
    urn:nbn:se:liu:diva-12773 (URN)10.1002/vnl.20131 (DOI)
    Available from: 2007-12-04 Created: 2007-12-04 Last updated: 2009-04-23Bibliographically approved
    2. Effects of an organotin stabilizer on anoxic degradation of organic matter
    Open this publication in new window or tab >>Effects of an organotin stabilizer on anoxic degradation of organic matter
    2003 (English)In: Journal of Water Management and Research / Vatten: Tidskrift för vattenvård, ISSN 0042-2886, Vol. 59, p. 271-277Article in journal (Refereed) Published
    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:liu:diva-12774 (URN)
    Available from: 2007-12-04 Created: 2007-12-04 Last updated: 2009-04-28
    3. Transformation of methyltin chlorides and stannic chloride under simulated landfill conditions
    Open this publication in new window or tab >>Transformation of methyltin chlorides and stannic chloride under simulated landfill conditions
    2011 (English)In: Waste Management & Research, ISSN 0734-242X, E-ISSN 1096-3669, Vol. 29, no 12, p. 1327-1336Article in journal (Refereed) Published
    Abstract [en]

    There is increasing concern regarding the fate of methyltins in the environment, particularly since large amounts of polyvinyl chloride (PVC) plastics are deposited in landfills. The potential transformation of methyltin chlorides and stannic chloride in landfills was investigated, by incubating the target substances at concentrations relevant to landfill conditions (100 and 500 mu g Sn L(-1)). The amounts of methane formed in all treatment bottles, and controls, were measured to evaluate the general microbial activity of the inocula and possible effects of methyltins on the degradation of organic matter. The methyltins and stannic chloride were found to have no significant inhibitory effects on the activity of landfill micro-organisms, and the methanol used to disperse the tin compounds was completely degraded. In some experimental bottles, the methanol degradation gave rise to larger methane yields than expected, which was attributed to enhanced degradation of the waste material. Alkyltin analyses showed that monomethyltin trichloride at an initial concentration of 500 mu g Sn L(-1) promoted methylation of inorganic tin present in the inoculum. No methylation activities were detected in the incubations with 100 mu g Sn L(-1) methyltin chlorides (mono-, di- or tri-methyltin), but demethylation occurred instead. Levels of soluble inorganic tin increased during the incubation period, due partly to demethylation and partly to a release of tin from the waste inocula.

    Place, publisher, year, edition, pages
    Sage Publications, 2011
    Keywords
    Landfill; methylation; methyltin chlorides; municipal solid waste; polyvinyl chloride; transformation
    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:liu:diva-12775 (URN)10.1177/0734242X10397088 (DOI)000297518600011 ()
    Available from: 2007-12-04 Created: 2007-12-04 Last updated: 2017-12-14
    4. Degradation of Organotin Stabilizers
    Open this publication in new window or tab >>Degradation of Organotin Stabilizers
    Manuscript (Other academic)
    Identifiers
    urn:nbn:se:liu:diva-12776 (URN)
    Available from: 2007-12-04 Created: 2007-12-04 Last updated: 2010-01-13
    5. Environmental analysis of organotin compounds in municipal solid waste by use of gas chromatography and atomic emission detection
    Open this publication in new window or tab >>Environmental analysis of organotin compounds in municipal solid waste by use of gas chromatography and atomic emission detection
    Manuscript (Other academic)
    Identifiers
    urn:nbn:se:liu:diva-12777 (URN)
    Available from: 2007-12-04 Created: 2007-12-04 Last updated: 2010-01-13
  • 6.
    Björn, Annika
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Miljövetenskap i sitt sammanhang2009In: Att lära för det okända - Miljövetarprogrammets jubileumsskrift, Linköping: LiU-Tryck , 2009, 1, p. 25-30Chapter in book (Refereed)
  • 7.
    Björn, Annika
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Reflektioner kring problembaserat lärande (PBL) som arbetsform på lab - erfarenheter från kursen "Vad är ett miljöproblem?".2003In: Från målbeskrivning till kunskapskontroll: 7:e universitetspedagogiska konferensen vid Linköpings universitet, Linköping: Centrum för undervisning och lärande (CUL) , 2003Conference paper (Refereed)
  • 8.
    Björn, Annika
    et al.
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Borgström, Ylva
    Pöyry Sweden AB, Norrköping, Sweden.
    Ejlertsson, Jörgen
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Karlsson, Anna
    Scandinavian Biogas Fuels AB, Stockholm, Sweden.
    Nilsson, Fredrik
    Pöyry Sweden AB, Norrköping, Sweden.
    Svensson, Bo
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Biogasproduktion inom svensk pappers- och massaporduktion : Syntes av möjligheter och begränsningar samt teknisk utvärdering: Bilaga 2 Etablering/effektivisering av biogasproduktion inom svensk pappers- och massaindustri2016Report (Other academic)
    Abstract [sv]

    Linköpings Universitet har tillsammans med Pöyry och Scandinavian Biogas Fuels drivit projektet ”Etablering/effektivisering av  biogasproduktion inom svensk pappers- och massaproduktion”. Potentialen hos det organiska materialet i avloppsvatten från svensk pappers- och massaindustri (PMI) till biogasproduktion skattades vid projektstart till 100 milj. Nm3 metan per år (1 TWh). Denna rapport är en syntes av resultaten från projektet med syfte att ge visa hur de genererade resultaten kan omsättas i teknisk praktik med tillhörande ekonomiska insatser. Syftet är att ge underlag och stöd till PMI-branschen och externa intressenter, som överväger att implementera biogasproduktion inom PMI.

    Substraten för biogasproduktion som återfinns i pappers- och massaindustrins avloppsvatten och slam kännetecknas av stora volymer med låga COD-halter. Detta kräver rötningstekniker, som tillåter mycket korta uppehållstider jämfört med mer traditionellt utformade biogasanläggningar för att inte tankstorleken ska bli för stor. Två tekniker, som utvecklats inom projektet, klarar detta: EGSB (expanded granular sludge bed) och CSTR (completely stirred tank reactor) med slamåterföring. Dessa tekniker har därför utvärderats för tre olika typbruk, ett CTMP-bruk, ett TMP-bruk och ett sulfatmassabruk. Resultaten från dessa experimentella studier är utgångspunkten för i utvärderingen i föreliggande rapport. För varje processkoncept har en grov kostnadsuppskattning (±20 %) gjorts för den investering som krävs för biogasproduktion.

    En EGSB på ett TMP-bruk med ett totalavlopp på 1500 m3/h, där hela blekeriavloppet från peroxidblekningen och en del av det övriga avloppet behandlas i en 4000 m3 reaktor förväntas ge 2,5 milj Nm3 metan/år. Investeringskostnaden för anläggningen uppskattas till 75 milj. SEK (±20 %).

    En EGSB på ett CTMP-bruk med ett totalavlopp på 170 m3/h där hela avloppet behandlas i en 3000 m3 reaktor förväntas ge 1,8 milj Nm3 metan/år. Investeringskostnaden för anläggningen uppskattas till 64 milj. SEK (±20%).

    En CSTR med slamåterföring som körs på bioslam från ett sulfatmassabruk där ett bioslamflöde på 46 m3/h behandlas i en 4000 m3 reaktor förväntas ge 1,0 milj Nm3 metan/år. I denna design är strategin för den aeroba bioreningen ändrad för att producera ett bioslam optimerat för att ge högsta möjliga biogaspotential. Detta innebär produktion av större mängd slam, som i största mån kan rötas till metan, dvs mängd metan per mängd rötat organiskt material samtidigt som COD-reduktionen i vattenreningen bibehålls. Investeringskostnaden för anläggningen uppskattas till 32 milj. SEK (±20%).

    Baserat på de COD-kvantiteter som når de luftade dammarna inom PMIs vattenreningssystem förbrukas årligen ca 0,8 TWh el. Införande av biogasproduktion i massaindustrins spillvattenrening skulle reducera mängden COD med mellan 30-50%, vilket får till följd att den årliga elförbrukningen i samband med den aeroba reningen går ner med ca 0,2-0,4 TWh. Detta innebär alltså ett energitillskott av 0,9 – 1,1 TWh givet att hela den tillgängliga biogaspotentialen skulle byggas ut. Till detta kommer eventuella vinster relaterade till slamhanteringen.

  • 9.
    Björn, Annika
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Ejlertsson, Jörgen
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Svensson, Bo H.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Anaerobic biodegradation of organotin stabilisers – Degradation capacity of landfill microorganisms2002In: Second Intercontinental Landfill Research Symposium (ICLRS), October 13-16, 2002. Asheville, North Carolina, USA, 2002Conference paper (Refereed)
  • 10.
    Björn, Annika
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Ekstrand, Eva-Maria
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Larsson, Madeleine
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Truong, Xu-Bin
    Cardell, Lina
    Borgström, Ylva
    Ejlertsson, Jörgen
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Svensson, Bo H.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Nilsson, Fredrik
    Karlsson, Anna
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    The methane potential of Swedish pulp and paper industry - A screening of wastewater effluents2012In: International Conference on Applied Energy 2012, 2012Conference paper (Other academic)
  • 11.
    Björn, Annika
    et al.
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Hörsing, Maritha
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Karlsson, Anna
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Mersiowsky, Ivo
    Hamburg, Germany.
    Ejlertsson, Jörgen
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Impacts of temperature on the leaching of organotin compounds from poly(vinyl chloride) plastics – A study conducted under simulated landfill conditions. Journal of Vinyl and Additive Technology 2007In: Journal of Vinyl & Additive Technology, ISSN 0193-7197, E-ISSN 1548-0577, Vol. 13, no 4, p. 176-188Article in journal (Refereed)
    Abstract [en]

    The aim of the study was to investigate whether organotin-stabilized poly(vinyl chloride) (PVC) products could contribute to the pool of organotins observed in landfill leachates, and if the possible release could be related to different temperatures and landfill degradation phases. Small-scale anaerobic reactors filled with generic household waste, a mixture of inocula, and different PVC plastics were used in the study and incubated at 20, 37, 55, and 70°C. The reactor units incubated at temperatures of 20–55°C underwent the anaerobic degradation phases that are characteristic for the aging of landfilled waste material. There were, however, differences in the duration of the phases as well as in the total biogas production among the units. Under methanogenic conditions greater losses of organotin compounds were observed as compared to acidogenic conditions. It was shown that the release of organotin stabilizers increases considerably at temperatures above the glass transition of the PVC products. A dealkylation from di- into monoalkyltin species was observed, as well as a possible methylation of inorganic tin. However, the main part of the organotins was adsorbed into the solid waste matrix. J. VINYL ADDIT. TECHNOL., 13:176–188, 2007. © 2007 Society of Plastics Engineers

  • 12.
    Björn, Annika
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Karlsson, Anna
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Shakeri Yekta, Sepehr
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Ejlertsson, Jörgen
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Danielsson, Åsa
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Svensson, Bo H.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Rheological characteristics of reactor liquid from 12 full-scale biogas reactors2012In: International Conference on Applied Energy, ICAE 2012, 2012Conference paper (Other academic)
    Abstract [en]

    Rheological properties of reactor liquids are important for the construction and intensity mixing systems in biogas reactors. Most frequently the total solids content (TS) is used as a proxy to guide in these matters. In order to establish a more comprehensive basis the rheology of twelve full-scale continuously stirred tank biogas reactors was characterized and related to differences in substrate composition and operational conditions. Reactor material from eight mesophilic (36−38°C) and four thermophilic (52−55°C) reactors were sampled at two occasions. The feedstocks of nine of these reactors were included in the analysis. Two of the mesophilic and one of the thermophilic digesters were fed sewage sludge (SS), while the others digested mixtures of organic matter including slaughterhouse waste (SHW), food industry waste (FIW), fat, manure, fodder residues and the organic fraction of municipal solid waste (OFMSW). The organic loading rates ranged 2.4−3.6 kg VS m-3 d-1 and the TS of the reactor materials were at 1.8−5.3% . The rheological characteristics of the reactor liquids were interpreted from flow- and viscosity curves as well as from determination of dynamic viscosity, limit viscosity, yield stress, flow behavior and consistency index.

    The fluid dynamic- and limit viscosities of the fluids ranged 5−600 mPa*s and 4−40 mPa*s, respectively. All reactor fluids except one from a thermohilic CD-reactor showed pseudoplastic behavior, since they became thinner with increasing shear stress until the viscosity reached a plateau of limit viscosity. In addition the mesophilic CD reactors were strongly thixothropic, i.e. they exhibited partial structure recovery. The results from the analysis of the thermophilic CD-reactors indicated a weak dilatant behavior, i.e. shear thickening behavior.

    The results showed differences in viscosity despite similar TS-content for several reactor liquids. From this survey it is clear that the TS content of biogas reactor fluids is not a good estimator of the fluid viscosity and that the fluid characteristics vary as a result of substrate composition and process operation conditions.

  • 13.
    Björn, Annika
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Segura de La Monja, Paula
    Karlsson, Anna
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Ejlertsson, Jörgen
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Svensson, Bo H.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Differences and shifts in the rheological characteristics of fluids in controlled stirred tank reactors for biogas production.2010In: World Conference in Anaerobic Digestion (AD12): in Guadalajara, Mexico, den 31 oktober – 4 november 2010., 2010Conference paper (Refereed)
  • 14.
    Björn, Annika
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Segura de la Monja, Paula
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Karlsson, Anna
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Ejlertsson, Jörgen
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Svensson, Bo H.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Rheological characterization2012In: Biogas / [ed] Sunil Kumar, Rijeka, Croatia: INTECH, 2012, p. 63-76Chapter in book (Refereed)
    Abstract [en]

    This book contains research on the chemistry of each step of biogas generation, along with engineering principles and practices, feasibility of biogas production in processing technologies, especially anaerobic digestion of waste and gas production system, its modeling, kinetics along with other associated aspects, utilization and purification of biogas, economy and energy issues, pipe design for biogas energy, microbiological aspects, phyto-fermentation, biogas plant constructions, assessment of ecological potential, biogas generation from sludge, rheological characterization, etc.

  • 15.
    Björn, Annika
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Svensson, Teresia
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Bastviken, David
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Öberg, Gunilla
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Problem-oriented laboratory work in environmental education: Experiences from a new master´s programme at Linköping Univerity, Sweden1999In: AuDes 5th Conference on Environmental Education, 1999Conference paper (Other academic)
  • 16.
    Björn (Fredriksson), Annika
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Anaerobic degradation of alkylmonoethanolamide ethoxylates, an alkylphosphate ester and an ethoxylate propoxylate1997Report (Other (popular science, discussion, etc.))
  • 17.
    Björn (Fredriksson), Annika
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Hörsing, Maritha
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Ejlertsson, Jörgen
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Svensson, Bo H.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Natural formation, degradation and occurrence of methyltins in different habitats.: Final report for Rohm & Haas, Cincinnati Ohio USA2003Report (Other academic)
  • 18.
    Björn (Fredriksson), Annika
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Hörsing, Maritha
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Karlsson, Anna
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Mersiowsky, Ivo
    Department of Waste Management, Technical University of Hamburg-Harburg, D-21079 Hamburg, Germany.
    Ejlertsson, Jörgen
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Impacts of Temperature on the Leaching of Organotin Compounds From Poly(vinyl chloride) Plastics: A Study Conducted Under Simulated Landfill Conditions2007In: Journal of Vinyl and Additive Technology, ISSN 1083-5601, Vol. 13, no 4, p. 176-188Article in journal (Refereed)
    Abstract [en]

    The aim of the study was to investigate whether organotin-stabilized poly(vinyl chloride) (PVC) products could contribute to the pool of organotins observed in landfill leachates, and if the possible release could be related to different temperatures and landfill degradation phases. Small-scale anaerobic reactors filled with generic household waste, a mixture of inocula, and different PVC plastics were used in the study and incubated at 20, 37, 55, and 70°C. The reactor units incubated at temperatures of 20-55°C underwent the anaerobic degradation phases that are characteristic for the aging of landfilled waste material. There were, however, differences in the duration of the phases as well as in the total biogas production among the units. Under methanogenic conditions greater losses of organotin compounds were observed as compared to acidogenic conditions. It was shown that the release of organotin stabilizers increases considerably at temperatures above the glass transition of the PVC products. A dealkylation from di- into monoalkyltin species was observed, as well as a possible methylation of inorganic tin. However, the main part of the organotins was adsorbed into the solid waste matrix.

  • 19.
    Björn (Fredriksson), Annika
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Jonsson, Susanne
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Ejlertsson, Jörgen
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Svensson, Bo H.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Interimreport 1 for the project on natural formation, degradation and occurrence of methyltins in different habitats.: Common project between Rohm and Haas, former Morton Plastics Additive (MPA), Cincinnati, Ohio, USA and the Department of Water and Environmental Studies (DWES), Linköping Univeristy, Sweden1998Report (Other academic)
  • 20.
    Björn (Fredriksson), Annika
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Jonsson, Susanne
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Ejlertsson, Jörgen
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Svensson, Bo H.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Interimreport 2 for the project on natural formation, degradation and occurrence of methyltins in different habitats.: Common project betweenRohm and Haas, former Morton Plastics Additive (MPA), Cincinnati, Ohio, USA and the Department of Water and Environmental Studies (DWES), Linköping Univeristy, Sweden.2000Report (Other academic)
  • 21.
    Björn (Fredriksson), Annika
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Mersiowsky, Ivo
    Thechnical University of Hamburg-Harburg.
    Ejlertsson, Jörgen
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Stegmann, R.
    Thecnical University Hamburg-Harburg.
    Svensson, Bo H.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Long term behaviour of organotin stabilised PVC products under landfill conditions.: Executive summary for the Organotin Environmental Programme (ORTEP) and Vinyl Institute, Technical University of Hamburg-Harburg, Hamburg, and Environmental Studies, Linköping University,2000Report (Other academic)
  • 22.
    Björn (Fredriksson), Annika
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Nestor, Gustav
    Svensson, Bo H.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Effects of an organotin stabilizer on anoxic degradation of organic matter2003In: Journal of Water Management and Research / Vatten: Tidskrift för vattenvård, ISSN 0042-2886, Vol. 59, p. 271-277Article in journal (Refereed)
  • 23.
    Björn (Fredriksson), Annika
    et al.
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Shakeri Yekta, Sepehr
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Ziels, Ryan
    Linköping University, Biogas Research Center. Department of Civil Engineering, University of British Columbia, Columbia, Canada.
    Karl, Gustafsson
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Svensson, Bo H
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Anna, Karlsson
    Linköping University, Biogas Research Center. Scandinavian Biogas Fuels AB, Stockholm, Sweden.
    Feasibility of OFMSW co-digestion with sewage sludge for increasing biogas production at wastewater treatment plants2017In: Euro-Mediterranean Journal for Environmental Integration, ISSN 2365-6433, Vol. 2, no 21Article in journal (Refereed)
    Abstract [en]

    Sweden has the ambition to increase its annual biogas production from the current level of 1.9 to 15 TWh by 2030. The unused capacity of existing anaerobic digesters at wastewater treatment plants is among the options to accomplish this goal. This study investigated the feasibility of utilizing the organic fraction of municipal solid waste (OFMSW) as a co-substrate, with primary and waste-activated sewage sludge (PWASS) for production of biogas, corresponding to 3:1 ratio on volatile solid (VS) basis. The results demonstrated that co-digestion of OFMSW with PWASS at an organic loading rate of 5 gVS l−1 day−1 has the potential to increase the biogas production approximately four times. The daily biogas production increased from 1.0 ± 0.1 to 3.8 ± 0.3 l biogasl−1 day−1, corresponding to a specific methane production of 420 ± 30 Nml methane gVS−1 during the laboratory experiment. Co-digestion of OFMSW with PWASS showed a 50:50 distribution of hydrogenotrophic and aceticlastic methanogens in the digester and enhanced the turnover kinetics of intermediate products (acetate, propionate, and oleate). Practical limitations potentially include the need for sludge dewatering to maintain a sufficient hydraulic retention time (17 days in this study), as well as additional energy consumption for mixing due to an increased sludge apparent viscosity (from 1.8 ± 0.1 to 45 ± 4.8 mPa*s in this study) at elevated OFMSW-loading rates.

  • 24.
    Björn (Fredriksson), Annika
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Svensson, Bo H.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Review paper on environmental aspects of organotins with emphasis on methyl- and butyltins: Occurrence, transformation, toxicity and analysis2001Report (Other academic)
  • 25.
    Björn (Fredriksson), Annika
    et al.
    Linköping University, Department of Educational Science (IUV). Linköping University, Faculty of Educational Sciences.
    Tibell, Lena
    Linköping University, Department of Educational Science (IUV). Linköping University, Faculty of Educational Sciences.
    Utvärdering av lärarutbildningens studieväg i naturvetenskap (HT04/VT05)2005Report (Other (popular science, discussion, etc.))
  • 26.
    Ejlertsson, Jörgen
    et al.
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Karlsson, Anna
    Linköping University, Biogas Research Center. Scandinavian Biogas Fuels AB.
    Björn, Annika
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Nilsson, Fredrik
    Linköping University, Biogas Research Center. Pöyry AB.
    Truong, Xu-bin
    Linköping University, Biogas Research Center. Scandinavian Biogas Fuels.
    Magnusson, Björn
    Linköping University, Biogas Research Center. Scandinavian Biogas Fuels AB.
    Larsson, Madeleine
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Ekstrand, Eva-Maria
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Biogas Research Center.
    Karlsson, Marielle
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Svensson, Bo
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Biogas from pulp and paper industry effluents.2014Conference paper (Other academic)
  • 27.
    Ejlertsson, Jörgen
    et al.
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Karlsson, Anna
    Linköping University, Biogas Research Center. Scandinavian Biogas Fuels AB.
    Björn, Annika
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Nilsson, Fredrik
    Linköping University, Biogas Research Center. Pöyry AB.
    Truong, Xu-bin
    Linköping University, Biogas Research Center. Scandinavian Biogas Fuels.
    Magnusson, Björn
    Linköping University, Biogas Research Center. Scandinavian Biogas Fuels AB.
    Larsson, Madeleine
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Ekstrand, Eva-Maria
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Biogas Research Center.
    Karlsson, Marielle
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Svensson, Bo
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Biogas from pulp andpaper industry effluents.2014Conference paper (Other academic)
  • 28.
    Ekstrand, Eva-Maria
    et al.
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Karlsson, Marielle
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Truong, Xu-Bin
    Scandinavian Biogas.
    Björn, Annika
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Karlsson, Anna
    Scandinavian Biogas.
    Svensson, Bo H.
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Ejlertsson, Jörgen
    Scandinavian Biogas.
    The route towards stable and efficient anaerobic digestion of fibrous wastewater from pulp and paper mills in high-rate CSTRs with sludge recirculation2015Conference paper (Other academic)
    Abstract [en]

    The pulp and paper industry carries high costs in wastewater treatment. By combining present techniques with anaerobic digestion (AD), expenses for electricity use and sludge disposal can be reduced. The large wastewater volumes require high-rate systems sensitive to suspended solids, and this has so far excluded treatment of the energy-rich wood fibres. In this study, AD of fibrous wastewater was examined in high-rate CSTRs with sludge recirculation. Two lab-scale reactors (4L) were run for 780 days. Once a day, reactor sludge was withdrawn and centrifuged. The main part of the supernatant was discarded, while the pellet was suspended with the substrate and returned to the reactor. This gave a sludge retention time of 10-16 days and a hydraulic retention time of 4-8 days. One reactor (denoted R1) was fed with fibre sludge, and the second reactor (denoted R2) was co-digesting fibre sludge and activated sludge. Both substrates were taken from a Kraft mill in Sweden. Initially, both reactors experienced frequent drops in pH, and continuous alkali supplements were necessary for process stability. Additions of magnesium and potassium were also needed to obtain stable process performance at an OLR of 3 g VS L-1·day-1. R1 and R2 behaved similarly, but R2 (co-digestion) was more robust with less or no fluctuations in VFA and pH. Addition of activated sludge also to R1 allowed an increase in OLR to 4 g VS L-1·day-1. In summary, stable and efficient operation of a high-rate CSTR with sludge recirculation digesting fibre sludge was achieved at an OLR of 4 g VS L-1·day-1, a HRT of 4 days and a methane production of 260±20 Nml. In addition, co-digestion with activated sludge stabilized the performance at increased OLR and thus gave more methane produced per reactor volume.

  • 29.
    Ekstrand, Eva-Maria
    et al.
    Linköping University, Department of Thematic Studies, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Larsson, Madeleine
    Linköping University, Department of Thematic Studies, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Truong, Xu-Bin
    Linköping University, Biogas Research Center. Scandinavian Biogas Fuels AB, Sweden.
    Cardell, Lina
    Linköping University, Biogas Research Center. Scandinavian Biogas Fuels AB, Sweden .
    Borgström, Ylva
    Linköping University, Biogas Research Center. Pöyry Sweden AB, Sweden .
    Björn, Annika
    Linköping University, Department of Thematic Studies, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Ejlertsson, Jörgen
    Linköping University, Department of Thematic Studies, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center. Scandinavian Biogas Fuels AB, Sweden.
    Svensson, Bo
    Linköping University, Department of Thematic Studies, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Nilsson, Fredrik
    Linköping University, Biogas Research Center. Pöyry Sweden AB, Sweden .
    Karlsson, Anna
    Linköping University, Biogas Research Center. Scandinavian Biogas Fuels AB, Sweden .
    Methane potentials of the Swedish pulp and paper industry - A screening of wastewater effluents2013In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 112, p. 507-517Article in journal (Refereed)
    Abstract [en]

    With the final aim of reducing the energy consumption and increase the methane production at Swedish pulp and paper mills, the methane potential of 62 wastewater effluents from 10 processes at seven pulp and/or paper mills (A-G) was determined in anaerobic batch digestion assays. This mapping is a first step towards an energy efficient and more sustainable utilization of the effluents by anaerobic digestion, and will be followed up by tests in lab-scale and pilot-scale reactors. Five of the mills produce kraft pulp (KP), one thermo-mechanical pulp (TMP), two chemical thermo-mechanical pulp (CTMP) and two neutral sulfite semi-chemical (NSSC) pulp. Both elementary and total chlorine free (ECF and TCF, respectively) bleaching processes were included. The effluents included material from wood rooms, cooking and oxygen delignification, bleaching (often both acid- and alkali effluents), drying and paper/board machinery as well as total effluents before and after sedimentation. The results from the screening showed a large variation in methane yields (percent of theoretical methane potential assuming 940 NmL CH4 per g TOC) among the effluents. For the KP-mills, methane yields above 50% were obtained for the cooking effluents from mills D and F, paper machine wastewater from mill D, condensate streams from mills B, E and F and the composite pre-sedimentation effluent from mill D. The acidic ECF-effluents were shown to be the most toxic to the AD-flora and also seemed to have a negative effect on the yields of composite effluents downstream while three of the alkaline ECF-bleaching effluents gave positive methane yields. ECF bleaching streams gave higher methane yields when hardwood was processed. All TCF-bleaching effluents at the KP mills gave similar degradation patterns with final yields of 10-15% of the theoretical methane potential for four of the five effluents. The composite effluents from the two NSSC-processes gave methane yields of 60% of the theoretical potential. The TMP mill (A) gave the best average yield with all six effluents ranging 40-65% of the theoretical potential. The three samples from the CTMP process at mill B showed potentials around 40% while three of the six effluents at mill G (CTMP) yielded 45-50%.

  • 30.
    Feiz, Roozbeh
    et al.
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, Faculty of Science & Engineering. Biogas Research Center.
    Ammenberg, Jonas
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, Faculty of Science & Engineering.
    Björn, Annika
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Yufang, Guo
    School of Environmental Science and Engineering, Guangzhou University, Guangzhou, China.
    Karlsson, Magnus
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Liu, Yonghui
    School of Environmental Science and Engineering, Guangzhou University, Guangzhou, China.
    Liu, Yuxian
    Linköping University. Guangzhou University Research Center on Urban Sustainable Development, Guangzhou University, Guangzhou, China.
    Masuda, Laura Shizue Moriga
    Institute of Biology, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
    Enrich-Prast, Alex
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Rohracher, Harald
    Linköping University, Department of Thematic Studies, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Trygg, Kristina
    Linköping University, Department of Thematic Studies, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Shakeri Yekta, Sepehr
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Zhang, Fagen
    School of Environmental Science and Engineering, Guangzhou University, Guangzhou, China.
    Biogas Potential for Improved Sustainability in Guangzhou, China: A Study Focusing on Food Waste on Xiaoguwei Island2019In: Sustainability, ISSN 2071-1050, E-ISSN 2071-1050, Vol. 11, no 6Article in journal (Refereed)
    Abstract [en]

    As a result of rapid development in China and the growth of megacities, large amounts of organic wastes are generated within relatively small areas. Part of these wastes can be used to produce biogas, not only to reduce waste-related problems, but also to provide renewable energy, recycle nutrients, and lower greenhouse gases and air polluting emissions. This article is focused on the conditions for biogas solutions in Guangzhou. It is based on a transdisciplinary project that integrates several approaches, for example, literature studies and lab analysis of food waste to estimate the food waste potential, interviews to learn about the socio-technical context and conditions, and life-cycle assessment to investigate the performance of different waste management scenarios involving biogas production. Xiaoguwei Island, with a population of about 250,000 people, was chosen as the area of study. The results show that there are significant food waste potentials on the island, and that all studied scenarios could contribute to a net reduction of greenhouse gas emissions. Several socio-technical barriers were identified, but it is expected that the forthcoming regulatory changes help to overcome some of them.

  • 31.
    Fredriksson (numera: Björn), Annika
    et al.
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Nestor, Gustav
    Linköping University, Department of Thematic Studies, Department of Water and Environmental Studies. Linköping University, Department of Thematic Studies, Tema Environmental Change.
    Svensson, Bo H.
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Effects of an organotin PVC stabiliser on anoxic degradation of organic matter2003In: Vatten, ISSN 0042-2886, Vol. 59, no 4, p. 271-277Article in journal (Refereed)
    Abstract [en]

    Many organotin compounds are toxic, thus their occurrence in the environment is of considerable concern, and several of these substances are regarded as priority pollutants that require further investigation. Organotins are used primarily as heat stabilisers in PVC plastic, and they are therefore found in landfills in which discarded PVC products have been deposited. In an earlier study, it was found that a widely used methyl tin PVC stabiliser inhibited microbial generation of CH4during anoxic degradation, and the objective of the present study was to elucidate possible mechanisms of such inhibition. CH4 and fermentation products were measured continuously for a period of 219 days in waste material amended with a methyl tin stabiliser. The results show that CH4 formation was retarded for 84-198 days during fermentation of the waste material. Furthermore, it seemed that not only the methyl tins, but also their sulphur organic ligands, play an important role in retarding the formation of CH4. The methyl tin stabiliser apparently affected both the fermentative organisms that provided the substrate for the methanogens, as well as the methanogens.

  • 32.
    Jidesjö, Anders
    et al.
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Björn, Annika
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Hedbrant, Johan
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, The Institute of Technology.
    Kalliokoski, Sophia
    Högskolan Dalarna, Akademin Utbildning, hälsa och samhälle.
    Petersson, Maria
    Högskolan Dalarna, Akademin Utbildning, hälsa och samhälle.
    Tydén, Thomas
    Högskolan Dalarna, Akademin Utbildning, hälsa och samhälle.
    Det goda lärandet: Energi, resurs, klimat ochhållbarhet som del i undervisningen i grundskolan & på gymnasiet2014Report (Other academic)
  • 33.
    Jidesjö, Anders
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Björn, Annika
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Hedbrant, Johan
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, The Institute of Technology.
    Kalliokoski, Sophia
    Högskolan Dalarna, Socialt arbete.
    Petersson, Maria
    Högskolan Dalarna, Biologi.
    Tydén, Thomas
    Högskolan Dalarna.
    Samhällets utvecklings- och omställningsförmåga: Framgångsrik skolutveckling för lärares arbete med och elevers lärande i energi, resurs, klimat och hållbarhet: Rapportering av forskningsinsatseri skolutvecklingsprojektet ”KNUT”2014Report (Other academic)
    Abstract [sv]

    Skolutvecklingsprojektet ”KNUT” genomförs i fyra större regioner i Sverige, från Kalmar län och Östergötland i södra Sverige via Dalarna till region ”Biofuel” i norra delarna av landet. Det övergripande syftet med projektet är att arbeta med samhällets påbud om att undervisning i områdena energi, resurs, klimat och hållbarhetsperspektiv behöver ha en starkare position, som en del av den grundläggande utbildningen.

    Till utvecklingsdelarna har forskningsinsatser genomförts. I varje region finns en mängd olika aktiviteter. Forskningen har inriktat sig på några av dessa med ett följeforskningsupplägg. I Kalmar län har projektet ”Tjejresan” (Kapitel 2) studerats. I Östergötland har lärares arbete med lokala pedagogiska planeringar följts (Kapitel 3). I Dalarna har projekten ”Energijakten” (Kapitel 4), ”Energiutmaningen” (Kapitel 5) och ”Sommarlovsentreprenörerna” (Kapitel 6) beforskats. Längst i norr har lärares arbete med projektarbeten och lärares kollegiala nätverk studerats (Kapitel 7). Till detta har en metastudie genomförts (Kapitel 8), för att utveckla en modell som tydliggör framgångsfaktorer för skolutveckling. Modellen har sin empiriska grund i delprojekten och har utvecklats och testats gentemot dessa.

    Projektet ”Tjejresan” i Kalmar län har handlat om den problematik som rör bristen på kvinnliga sökande till utbildningar inom naturvetenskap och teknik. Projektet har involverat kvinnliga elever, som i gymnasieskolan valt sådana utbildningsinriktningar. I projektet har eleverna besökt aktörer utanför skolan som arbetar inom områdena energi, resurs, klimat och med hållbarhetsfrågor för att inspirera till kvarhållande samt framtida val inom dessa utbildningsområden. Positiva förebilder har utgjort ett viktigt inslag. Forskningen har handlat om att uppmärksamma elevernas perspektiv på dessa aktiviteter. Empiri har samlats genom enkätinsamling samt deltagande med observations- och intervjumetodik. Resultaten visar att lärare som eleverna mött tidigare och deras hantering av ämnesinnehållet var viktigt för elevernas val till gymnasieskolan, liksom andra viktiga personer i deras omgivning samt tron på en utbildning med stora valmöjligheter. Tjejerna i ”Tjejresan” resonerar också om att skolans sätt att framställa innehållet ofta saknar sammanhang och diskussion samt att de upplevt besöken utanför skolan som viktiga för att förstå något om kunskapens användning. Eleverna talar om att de fått en verklighetsanknytning. Eleverna knyter på så vis aktiviteterna till sitt lärande i skolan, men de talar även om inspiration inför vidare studier. Diskussionen om resultaten är knutna till frågor om utökat samarbete och medvetenhet mellan olika aktörer, betydelser av lärande i och utanför skolan samt läraruppdragets förändrade roll.

    I kapitel 3 redogörs för lärares arbete med långsiktiga pedagogiska planeringar (LPP). Samarbete mellan lärare i skolor samt mellan stadier för att skapa en förståelse för innehållets progression och vad som görs i olika delar av skolsystemet har studerats. Empiri har samlats från de lärare som arbetat med att upprätta LPP i form av enkäter i samband med att arbetet startade och implementerades. Resultaten visar två huvudinriktningar. En grupp lärare svarar att arbetet varit framgångsrikt i termer av att det funnits stöd och uppmuntran, att det skapar viktiga diskussioner i arbetslag och att det utvecklat undervisningen. Andra har varit mer tveksamma. Majoriteten av lärare var positiva inför möjligheten att sprida LPP till kollegor när arbetet startade, men många fler var tveksamma i samband med implementeringen. Eleverna har i princip inte varit involverade alls i dessa arbeten utan behandlas som mottagare av undervisning när arbetet med LPP är genomfört. Resultaten diskuteras gentemot betydelse av involvering, förhärskande skolkultur, kollegialt lärande och specifikt elevers involvering. Kvaliteter inom dessa områden är diskuterade som troliga för att ytterligare utveckla arbetet.

    I projektet ”Energijakten” har årkurs 8 elevers besök på ett science center, Framtidsmuséet i Borlänge, studerats. Empiri är samlad från lärare, som tidigare deltagit i dessa aktiviteter, deltagande observationer under energijaktsdagar samt intervjuer med lärare och personal från Framtidsmuséet. Resultaten visar att lärare uppfattar att deras elever blivit mer medvetna om och ökat sina kunskaper om energifrågor. Resultaten varierar dock mellan olika skolor. I vissa resultat beskrivs en skolkultur där schemabrytande aktiviteter välkomnas och uppmuntras. På dessa skolor tas inspiration och erfarenheter från besöken vidare. I andra delar av resultaten beskrivs en skolkultur där olika problem skapar hinder för utveckling. För att projektet ska få utökat genomslag skulle olika skolor behöva en variation av stöd och insatser, som är anpassade till olika förutsättningar. Resultaten diskuteras i relation till behov av projektkontextualisering.

    ”Energiutmaningen” (Kapitel 5) handlar om att öka barns intresse för energi- och miljöfrågor samt stärka lärare i sådana arbeten. Forskningen har handlat om deltagande observationer och gruppintervjuer med elever och lärare. Resultaten visar att eleverna är positiva till materialet och att de fått ökade kunskaper om vad energieffektivisering innebär. Eleverna menar också att de har praktisk vardagsnytta av kunskaperna de lärt sig i skolan. Även lärarna är positiva till projektet och anser att det fungerar bra. Vissa lärare har dock svårigheter med att se hur områden, som energi, resurs, klimat och hållbarhet, ska kunna läggas in på befintliga skolämnen och talar om dessa som nya områden. Att projektet sätter avtryck och uppskattas av lärare och deras elever diskuteras i relation till betydelsen av involvering och delaktighet. Betydelse av förankring på en skola, lärargruppens förutsättningar samt respekt för omständigheter som finns i en lokal miljö med stöd från projektledning lyfts fram och diskuteras som viktiga kvaliteter.

    Sommarlovsentreprenörerna (Kapitel 6) är en aktivitet som pågår utanför skolan under sommarlovet. Elever i åldrarna 14-20 år arbetar med att starta och driva ett eget företag med miljö- och hållbarhetsfokus. Forskningen har samlat empiri genom intervjuer med konceptansvarig, handledare, coacher, deltagare i projektet, samt representant för Falu kommun. Resultaten visar att aktiviteterna lever upp till syftet med att lyfta in frågor om miljö och hållbarhet i arbetet. Resultaten indikerar att konceptet skapar ett engagemang hos ungdomarna. Diskussionen förs i relation till att redan befintliga verksamheter kan ta in nya frågor. Det behövs inte alltid nya projekt för att energi, resurs, klimat och hållbarhet ska bli en starkare del av ett lärande. Resultaten indikerar också att framgång i energiutmaningen rymmer kvaliteter som att deltagarna äger uppgiften samt att de förstår mening och relevans kopplat till vad de håller på med i aktiviteten.

    Kapitel 7 handlar om lärarnätverk och projektarbeten i gymnasieskolan. Särskilt energifrågor och energiomställning lyfts fram. Kring arbetet med projektarbeten finns ett etablerat lärarnätverk, som erbjuder stöd till elever. I arbetet ingår också en stipendietävling. I arbetet förekommer näringslivskontakter så projektet rymmer, precis som ”Tjejresan” (Kapitel 2), skolans relationer med aktörer i samhället. Forskningen har handlat om vilka avtryck dessa aktiviteter sätter i form av framtida studier och yrkesval. Empirin är samlad genom intervjuer med lärare, samt genom uppföljande intervjuer med tidigare elever. Vidare har en innehållsanalys genomförts av projektarbeten. Resultaten visar att lärarna är positiva till nätverket och upplever stöd från skolledning. Lärarna är positiva till den fortbildning de blivit erbjudna i nätverket. Resultaten indikerar att nätverket har betydelse för lärarnas långsiktiga engagemang för frågor om energiomställning, hållbar utveckling och miljöfrågor. De tidigare eleverna beskriver att skolans verksamhet med stipendier var något positivt. Däremot är de inte lika tydliga med att koppla dessa skolaktiviteter till val av framtida utbildning och yrkesliv. De beskriver istället att deras intresse för naturvetenskap och teknik grundlades tidigt. Aktiviteterna har haft en funktion i att uppmuntra och skapa stolthet. Resultaten diskuteras i relation till lärare som nyckelpersoner för att föra in kvaliteter i relationen mellan skola och omgivande samhälle. Lärarnas engagemang, samt långsiktigheten genom ett nätverk, borgar för att projektet övergår till en process och blir en del av skolans verksamhet. Involvering av lärare och deras elever i meningsfulla aktiviteter, diskuteras som en förutsättning för att energi-, miljö- och hållbarhetsfrågor ska bli en del av skolans genomförande.

    Kapitel 8 redovisar ett sätt att modellera frågor om skolutveckling, som tydliggör olika faktorsteg i de processer som uppstår. Modellen är utvecklad ifrån tidigare teoribildning och anpassad till skolans verksamhet. Faktorerna Visionen, Lokal organisation, Yttre aktörer, Nyckelpersoner, Produkt, Mottagare, Resultat, samt Andra faktorer har identifierats. Modellen testades på några av de olika delstudierna. Resultaten visar att modellen kan användas och att den strukturerar och identifierar kritiska steg i de processer som uppstår vid skolutveckling. Faktorerna är inte statiska utan har en dynamisk karaktär. De kan vara svåra att påverka, definiera och möta. Eftersom varje projekt är unikt kräver modellen en flexibel användning. Syftet har inte varit att identifiera en slutgiltig modell, som är det rätta sättet att uppfatta skolutveckling. Den har utvecklats för ett sätt att analysera ett projekt, för att identifiera kritiska faktorer och steg i de processer som kan uppstå. Testningen av modellen illustrerar exempel på användbarhet.

    Denna rapport redovisar dessa sju delstudier tillsammans med ett introducerande kapitel, som ger en fördjupad och kritisk framställning av olika forskningssammanhang. Kapitel ett utgör på så vis en tolkningsram, samtidigt som det identifierar möjligheter och hinder, som kommande projekt och studier behöver ta sig an. I kapitel ett identifieras ett antal utmaningar, som kan kallas för ramfaktorer. De utgör kontexter, yttre ramverk, som behöver hanteras i skolutvecklingsprojekt. De är identifierade som viktiga att hantera i de processer som kan uppstå vid skolutveckling. De utgör på så vis kritiska faktorer, som kan bidra till att skolutvecklingsprojekt inte når hela vägen in i klassrum.

    Den första ramfaktorn handlar om relationer mellan det nationella, regionala och lokala. Det uppstår förskjutningar på olika nivåer i dessa relationer. En viktig fråga är därför var problem, som uppstår på de olika nivåerna hanteras. I det nationella ingår till exempel skolans uppdrag, påbud från olika aktörer och projektsatsningar. Det finns tidigare forskning, som har kunnat visa att förändringar på den nationella nivån har begränsad inverkan på det som händer i klassrum. Det tillkommer villkor i skolans omsättning av uppdraget, som på den lokala nivån bidrar till att förskjuta utbildningens genomförande i olika riktningar. Syn på lärande och lärares arbete med elevernas involvering är viktiga delar i detta. Det uppstår asymmetrier i relationen nationellt – lokalt, som behöver förstås för att kunna tolka, hantera och utveckla läraruppdraget. Därför behövs också en kunskapsuppbyggnad kring dessa förhållanden. I avsnitt 1.2 utvecklas dessa resonemang.

    Att hjälpa lärare förstå skolans roll i samhällsutvecklingen och hur utbildningens funktion varierar i tid är en ytterligare ramfaktor, som också skapar motiven för betydelse av undervisning inom områdena energi, resurs, klimat och hållbarhetsperspektiv. Den historiska förankringen är viktig för att förstå något om skolans situation, som den ser ut idag. Om skolutvecklingsprojekt startar, med ambitioner att förändra kan den historiska förankringen involvera aktörer i varför sådana arbeten är angelägna. Om syftet med olika satsningar istället är oklart kommer åtgärder tendera att ibland bli planlösa. Planlösa i bemärkelsen att de saknar förankring. Det är förankringen som kan bidra till att hålla en riktning. Ett sätt att göra detta mer konkret är att diskutera undervisningsinnehållets identitet och legitimitet. Om sådana mer grundläggande förhållanden blir oreflekterade är det svårt att förstå och tolka skolans uppdrag. Detta utvecklas i avsnitt 1.3.

    Möten med innehållet i och utanför skolan utgör en tredje ramfaktor och finns beskrivet i avsnitt 1.4. Samhällets utveckling skapar nya förutsättningar för lärande. I flera av delstudierna återkommer frågor som handlar om samarbeten. Det kan röra arbete inom en skola, mellan skolor och med andra aktörer i samhället. Individer kommer idag i kontakt med innehållet på olika sätt. Levd erfarenhet genom deltagande i handling utgör en aspekt av erfarenheter. Allt viktigare blir olika representationer. Det finns en mängd andra aktörer som idag exponerar samma innehåll som skolan, fast på andra sätt. Medierad erfarenhet ingår därför som en allt viktigare förutsättning för lärande. Individers erfarenhetsrepertoar av ett innehåll ser annorlunda ut idag jämfört med tidigare generationers. Tillgängligheten till olika sätt att hantera innehållet ökar. Särskilt intressant blir detta när skolan förväntas samarbeta med externa aktörer. Science center utgör ett sådant exempel på resursmiljö för skolan. Hur kan miljöer utanför skolan engageras, för att berika lärandet i skolan? I kunskapsbegreppet ingår dels att sätta namn på saker, dels att förstå, men också att sätta sig in i kunskapens användning. Dessa tre dimensioner av kunskap är bärande för utbildningens uppdrag. Hur kan utbildningen komponeras så att kunskapsbegreppet tas på allvar?

    Vidare har Goda möten identifierats som en angelägen ramfaktor, och finns återgivet i avsnittet 1.5. På vissa skolor sker utvecklingsarbete och på andra inte. Vissa lärare ser hinder när andra ser möjligheter. Förhärskande skolkulturer, konkurrerande verksamheter och svårigheter med att se hur innehåll som energi, resurs, klimat och hållbarhet får plats i befintliga skolämnen är exempel på sådant som påverkar utveckling. Olika skolor har olika behov. Hur ser det goda mötet ut, en framgångsrik dialog, som möter, respekterar och förmår hantera variationer i förutsättningarna? Betydelse av medverkan, äkta involvering, förankring och att skapandet av ny kunskap baseras på den kunskap som redan finns är exempel på viktiga utgångspunkter för en fungerande pedagogik.

    Vidare redovisas i avsnittet 1.6 en fördjupad framställning kring hållbarhetsperspektiv där innehållsfrågans eftersläpning lyfts fram som en kritisk ramfaktor. Flera exempel på forskning återges, som pekar på behovet av att förstå diskussioner om samhällsomställning i relation till konkreta innehållsområden. Energi-, miljö- och hälsoområdena är tydligt diskuterade. Kopplingar mellan ekologiska och ekonomiska perspektiv har dominerat diskussioner, ofta på bekostnad av sociala. Förståelse för människans resursanvändning, och för ekonomisk utveckling är beroende av upplysning om relationen mellan människa och natur. Det pågår en debatt om det behövs ett eget skolämne för att något om hållbarhet ska bli en del av utbildningen eller om uppdraget kan formuleras och organiseras som alla lärares angelägenhet. Om grundläggande utbildning, ska handla om upplysning om kulturen, för individers rätt till att bilda sig en egen åsikt i viktiga frågor krävs ett uppdaterat utbildningssystem, som har kapacitet att göra viktigt innehåll tillgängligt. Frågan har en allvarsam underton. Den handlar i grunden om ett samhälles förmåga att involvera individer i verkliga samhällsfrågor, som upplyser om kulturen. Alternativet kan bli bidrag till känslor av utanförskap. En kunskapsuppbyggnad kring vad olika utbildningsinriktningar betyder för ett samhälles möjligheter till utveckling och omställning, kommer spela en avgörande roll i den utveckling som kommer.

    I avsnitt 1.7 finns en kritisk redogörelse för utbildningens förmåga att förbereda för vidare studier och samtidigt ge alla elever en allmänbildning. Utbildningens förmåga att vara såväl rekryterande som allmänbildande är identifierad som en sjätte ramfaktor. Om samhället står inför energiomställning, att hantera miljö- och hållbarhetsfrågor behövs expertis. Lika viktigt är en allmänbildad befolkning. Projekt som tar sig an dessa utmaningar behöver balansera. I avsnittet 1.7 redovisas brister i begreppsanvändning i sådana diskussioner. Finns det ett rekryteringsproblem och vad har det i så fall för karaktär? Två konkreta empiriska underlag om rekrytering till gymnasie- och högskolenivå visas, som också indikerar ett behov av att väga in reformeffekter i diskussioner om elevers bristande intresse för vissa utbildningsval. Det empiriska underlaget visar bland annat att högskolesatsningen på 1990-talet i stort ledde till massutbildning inom samhällsvetenskap, juridik, handel och administration. Sverige verkar inte ha lyckats förändra rekryteringen varken inom områdena naturvetenskap, matematik och data eller inom teknik och tillverkning. Avsnitt 1.7 ställer ett antal kritiska frågor om utbildningens situation, som försöker fånga problematikens karaktär. Allvaret i detta handlar om att bygga upp kunskap så att frågor blir rätt formulerade, att projekt inriktar sig på verkliga orsaker till oönskade effekter samt att ansvarsförhållanden blir tydliggjorda i utrop om olika åtgärder.

    Sveriges förmåga till energiomställning, att hantera miljöutmaningar, hälsoproblem och hållbarhetsperspektiv kräver å ena sidan en utbildning som förbereder för vidare studier och rekryterar framtidens expertis. Lika viktigt är att utbildningen är komponerad så det finns en kapacitet att allmänbilda alla, förbereda för samhällsliv och deltagande i kulturen. En modern utbildning ska kunna hantera båda uppdragen. Ett samhälle blir troget sig självt när det upplyser om och inkluderar sin befolkning i det som är angeläget i kulturen. På så vis är ett uppdaterat utbildningssystem ryggraden i en demokratisk samhällsordning. Att fördunkla viktigt innehåll, hänger samman med utanförskap, känslor av exkludering och att skolan inte upplevs som en meningsfull miljö.

    På en övergripande nivå visar resultaten att områdena energi, resurs, klimat och hållbarhet skulle kunna utgöra delar av nya visioner för utbildningen. Det skulle kunna öka Sveriges konkurrenskraft och bidra till individers inkludering i verkliga utmaningar. Områden som behöver utvecklas för en sådan inriktning är lärares förståelse för relationer mellan det nationella, regionala och lokala. En sådan förståelse är nödvändig för att kunna tolka skolans uppdrag och omsätta det i konkret undervisning, där elevernas förutsättningar för lärande ingår. Lärare behöver också förstå sitt arbete mer i relation till samhällsutveckling och utbildningens funktion. En sådan förståelse ger identitet åt utbildningens innehållsaspekt. Om utbildningen ska förbereda för samhällsliv, måste samhällslivet vara en utgångspunkt för utbildningen. Skolan är inte ensamt om upplysningsfunktionen. Individer möter innehållet både i och utanför skolan. Skolan ska inte vara i konkurrens med omgivande samhälle. Variationer i innehållets hantering kan utgöra en resurs. Goda möten, som väger in skolkultur, uppdaterar befintliga skolämnen, skapar medverkan och förankring är viktiga. Att lyfta enskilda lärare, som sen ska entusiasmera sina kollegor kan vara en svår väg att gå. Resultaten i detta arbete indikerar snarare betydelsen av lärares deltagande i utvecklingsprocesser, i vilka även eleverna borde ingå i om det ska hända något i den konkreta undervisningens genomförande.

    Vi lever i ett samhälle som har genomgått modernisering. Visionerna om att bygga och konstruera välfärd är förbi. Samhället har idag svårt att formulera nya visioner. Om vi inte vet vad vi ska hålla på med några generationer framåt, är det inte konstigt om utbildningens funktion blir svår att formulera. Det är vanskligt att säga något om framtiden, men det är också knepigt att dra slutsatsen att skolan ska fortsätta undervisa det innehåll, som bistod det förra samhällsprojektet. Då är det den situationen vi ska tala om. Vad behöver lärare för stöd i detta? Lever vi kvar i en föreställning om att skolan är en plats som ska leverera svar? Exakta svar, för ett industrisamhälles förmåga till utveckling.

    Alternativ skulle kunna handla om utbildningens kapacitet att bistå samhällets behov av energiomställning och hantera människans resursanvändning med miljö- och hälsokonsekvenser i hållbarhetsperspektiv. Berättelsen om samhällets utveckling och på vilket sätt utbildningen spelar roll, dess funktion, skulle kunna utgöra ett klister mellan det som är viktigt och lärares vardag. Det skulle kunna ge en riktning, som en skylt, i vilken angelägenheten och motivationen för att arbeta med energi, resurs, klimat och hållbarhetsfrågorna ingår. Utbildningen behöver bli förknippad med berättelsen. Ge lärare chansen att äga en sådan utvecklingsprocess tillsammans med sina elever. Det är när de ser förtjänsterna med en sådan process, som det kommer hända viktiga saker i klassrum.

  • 34.
    Jidesjö, Anders
    et al.
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Björn, Annika
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Tydén, Thomas
    Högskolan Dalarna, Akademin Utbildning, hälsa och samhälle.
    Uhrqvist, Ola
    Linköping University, The Tema Institute. Linköping University, Faculty of Arts and Sciences.
    Rapportering av fördjupande forskningsinsatser kopplade till skolutvecklingsprogrammet ”KNUT3”: En berättelse om vad en transformativ inriktning på utbildningens genomförande kan innebära för skolutveckling och möjligheter till meningsfullt lärande2015Report (Other academic)
    Abstract [sv]

    Denna forskningsrapport rapporterar från tre studier genomförda på skolutvecklingsprogrammet ”KNUT3”, som genomfördes under 2014. Forskningen bygger vidare på de resultat som rapporterats i tidigare forskning på samma skolutvecklingsprogram, fast då ”KNUT2” (Jidesjö et al., 2014). Resultaten som rapporteras här vilar således på ett omfattande empiriskt underlag, som korresponderar med verksamheter från förskola upp till och med gymnasieskola. I en övergripande beskrivning handlade ”KNUT” om att hitta sätt att arbeta för att involvera utbildningen mer i verkliga samhällsutmaningar och sätt att arbeta med lärare som sätter avtryck i klassrum och kommer elevernas lärande till del. Områden som arbeten varit koncentrerade till är energi, resurs, klimat och hållbarhetsfrågor. Ett viktigt resultat som identifierades i den förra forskningsrapporten handlar om att bygga skolutveckling inifrån. Det innebär arbeten som utgår ifrån elevers förutsättningar för lärande och ger lärare och elever möjligheter att äga sådana processer. Denna forskningsrapport fördjupar vad ett sådant arbete innebär, vilka förtjänsterna kan vara och hur utmaningar kan hanteras.

    Forskningsinsatserna har i allt arbete som rapporteras här utgått ifrån ett följeforskningsupplägg. Det innebär att forskningen haft två funktioner. Dels att tillse att aktiviteter som genomförs har en relation till forskning och vetenskap. Arbetet handlar då om att ta del av tidigare studier och skapa möten med inblandade lärare och andra aktörer, där dessa resultat kan presenteras på ett sätt att de kan omsättas i pågående arbete. Den andra funktionen handlar om att bedriva ny forskning, som genererar en kunskapsuppbyggnad. Även dessa processer är riggade på ett sätt så att framför allt lärare kan ta del av och även påverka forskningens upplägg och inriktning. Forskningsarbetet bygger således starkt på närvaro under pågående arbete istället för att ha en mer utvärderande karaktär i efterhand.Rapporten bygger på empiriska underlag från tre ingående delstudier.

    Den första återfinns i kapitel två och handlar om lärares perspektiv på utforskande och undersökande arbetssätt i förskola och grundskola. Empirin är genererad via fokusgruppsmetodik med yrkesverksamma lärare som givits möjlighet att reflektera och diskutera kring användandet och implementeringen av material som är mer elevaktiva och öppna i sin karaktär. Resultaten visar att lärares vilja att engagera sig i utvecklingsarbete är kopplat till materialets utformning och rymmer en innehållsdimension samt koppling till samhällsrelevans. Lärarna lyfter också betydelse av involvering av barnens föräldrar i arbetet samt att aktiviteter som utförs har en påverkan på familjelivets handlingar. Breda kontakter med natur och samhälle är ytterligare dimensioner som lyfts fram som viktiga förutsättningar för meningsfullt lärande. Resultaten diskuteras i relation till läraryrkets professionsutveckling, synsätt på undervisning och lärande som förutsättningar för kvalitetsarbete och betydelse av en utbildning som är i takt med tiden.

    Det andra arbetet som rapporteras i kapitel tre, handlar om fördjupande studier kring flickors val av utbildning och hur insatser kan göras för att påverka utbildningsval. Ett rekryteringsperspektiv har genomförts i projektet ”Tjejresan” som pågått i svenska gymnasieskolor. Flickor som valt att studera inom naturvetenskapliga och tekniskt inriktade program har erbjudits möjlighet till aktiviteter där de fått besöka företag och arbetsliv och beretts möjligheter att få inblick i hur andra aktörer utanför skolan arbetar med innehåll. Arbetet har pågått i flera år och forskningsinsatserna har följt utvecklingen. De empiriska underlagen grundar sig i enkätstudier med aktuella elever i kombination med intervjustudier. Till detta har även uppföljande intervjuer genomförts med kvinnor som idag avslutat sin gymnasiala utbildning och befinner sig i olika positioner i samhället. Resultaten indikerar att insatserna haft betydelse, men en begränsad påverkan för utbildningsval. Viktiga faktorer som framkommit rör sig kring intresse för innehållet samt den nära familjens betydelse och att intresse är något som grundlagts betydligt tidigare. Insatserna sent i utbildningssystemet verkar mest ha påverkan för att bibehålla och stimulera intresset genom att skapa relationer mellan skola och arbetsliv och demonstrera karriärvägar. Resultaten är diskuterade i relation till möjligheter att arbeta mer med intresset i grundskolan samt att när det gäller frågan om utbildningsval och rekrytering, öppna upp för möjligheter att föräldrar och den nära familjen är mer involverade i skolarbetet.

    Kapitel fyra innehåller den tredje delstudien och rapporterar ett lärarperspektiv på nätverksarbete och kollegialt lärande. Studien handlar om att öka förståelsen för vad ett nätverk kan vara och innebära. Empirin är genererad från lärare i gymnasieskolan, som ingått i ett nätverk under längre tid och som intervjuats för att kunna delge sina berättelser och reflektioner kring nätverkets och det kollegiala lärandets innebörder. Empirin är sedan framställd kring aktuell teoribildning. Tillsammans identifierar studien ett antal viktiga faktorer, som diskuteras i relation till förtjänster och möjligheter för att stimulera en professionell inriktning på lärararbetet.

    Rapporten är skriven så att delstudierna kan läsas självständiga. För att inordna dem i ett större sammanhang inleds rapporten med ett kapitel där delstudiernas resultat sätts in i ytterligare teoribildning och perspektiv, som hjälper till att tolka innebörder. Aktuell forskning och teoribildning om lärande och kvalitetsarbete har hämtats genom att anlägga historiska, sociologiska och utbildningsvetenskapliga perspektiv. Texten gör inga anspråk på att vara heltäckande och argumenterar inte för en bestämd inriktning. Den är skriven för att bidra som en tolkningsram åt delstudierna och har således empirisk resonans. Forskningsinsatserna har bedrivits utifrån ett följeforskningsperspektiv, som innebär att vetenskaplig och erfarenhetsbaserad kunskap möts för att i gemensamma överläggningar identifiera viktigt arbete där alla kan bidra.

    Det inledande kapitlet lyfter frågor om betydelse av att utvecklingsarbeten i skolan initieras och byggs inifrån elevers förutsättningar för lärande och vidare ut i dynamiska förbindelser med omgivande samhälle. Texten har identifierat traditioner i syn på begåvning, talang och lärande som viktiga att reflektera för att förstå innebörd av andra synsätt. En strävan att åstadkomma en professionell inriktning på utbildningens genomförande har anlagts genom en transformativ inriktning som därpå beskrivs med konkreta dimensioner som kan förstärka och stimulera en sådan inriktning. Sådana dimensioner handlar om egenskaper i ledarskap, barnsyn, samarbete med barns familjer, kontaktytor med natur och samhällsliv, hur grupper sätts samman, hur bedömning byggs upp, egenskaper i arbetsmaterial och betydelse av en lärande gemenskap som innebär att hela skolan arbetar mot gemensamma målsättningar.

    Slutsatser som reflekteras i detta inledande kapitel handlar inte om att problem för utbildningens genomförande handlar om arbeten som tar fram fler resurssidor i form av tips och tricks, som lärare förväntas ta del av och sedan exponera för elever. Kunskaper och drivkrafter för kreativitet i metodik bör istället växa fram som en konsekvens av identifierade problem, så att lärare och deras elever formar och därifrån får stöd som ger insatser som berör deras verkliga bekymmer. I sådana processer kan barnens hemmiljöer, material, bedömning, ledningsfunktioner, forskning och omgivande samhälle träda in och stötta en kunskapsutveckling som successivt introducerar kommande generationer till samhällets utmaningar. En sådan transformativ inriktning gör att samhället på lång sikt blir mer trovärdigt eftersom utbildningen får en förankring i verkliga verksamhetsformer. Annorlunda kan man uttrycka detta som att olika länkar behöver finnas, för att de ska kunna aktiveras vid behov. Exakt när sådana behov uppstår utgör den dynamiska karaktären mellan utbildningens inre och yttre dimensioner, som gör det svårt att fånga innebörden i statiska uttryck. En fastare förankring för utbildningen i samhällslivets vedermödor är identifierad som en viktig fortsättning för kommande studier. Sådana förankringar borde kunna åstadkommas i delvis nya strukturer, med anledning av kommunikationsmediernas allt mer betydande inslag för informationsspridning. Innebörder av hur gestaltningar i det lokala, regionala, nationella och internationella involverar individer och tar sig uttryck, har med produktions- och receptionskontexter att göra och är en trolig viktig fortsättning i förståelse av och för att förstärka den professionella inriktning för lärararbetet, som skisserats i denna forskningsrapport.

  • 35.
    Jidesjö, Anders
    et al.
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Danielsson, Åsa
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Björn, Annika
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Interest and Recruitment in Science: A Reform, Gender and Experience Perspective2015In: Procedia - Social and Behavioral Sciences, ISSN 1877-0428, E-ISSN 1877-0428, Vol. 167, no 0, p. 211-216Article in journal (Refereed)
    Abstract [en]

    This paper reports on Swedish results from a worldwide research project concerned with the Interest and Recruitment in Science Education (the IRIS-International study) together with results from a longitudinal national study on girl's views on out of school experience in science and technology in upper secondary education. The studies are framed in the structural situation of the Swedish educational system. The results show that there are reform and policy effects to consider in the discussion of recruiting more students in STEM. Interest in the subject, earlier school experience, achievement and teacher feedback is found to be important for educational choice in STEM. Specifically girls point out societal relevance as important. In addition there are elements outside the school setting with importance for educational choice. Moreover, girls point out visits to a museum and watching films and boys popularized forms of science and computer games. All students consider TV and activities outside school as important for their educational choice in STEM. When trying to implement outside school experience with girls in a longitudinal study in upper secondary education the interplay with school subject teaching is identified as missing. The friction between subject teaching in schools and connections with the surrounding world is proposed as important for future studies.

  • 36.
    Jidesjö, Anders
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Hedbrant, Johan
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, The Institute of Technology.
    Björn, Annika
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Intresseväckande naturvetenskaplig undervisning - Exemplet tematisk naturvetenskap2007Conference paper (Other academic)
  • 37.
    Karlsson, Anna
    et al.
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Björn, Annika
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Sepehr, Shakeri Yekta
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Svensson, Bo
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Improvement of the Biogas Production Process: Explorative project (EP1)2014Report (Other academic)
    Abstract [en]

    There are several ways to improve biogas production in anaerobic digestion processes and a number of strategies may be chosen. Increased organic loading in existing plants will in most cases demand the introduction of new substrate types. However, to substantially increase the Swedish biogas production new, large-scale biogas plants digesting new substrate types need to be established.

    Better utilization of existing digester volumes can be linked to: 

    • Increase of organic loading rates and/or reduced hydraulic retention time
    • Optimizing the anaerobic microbial degradation by identifying rate-limitations, its causes and possible remedies such as:
    • Nutrient and trace element balances
    • Needs and availability of trace element
    • Process design aiming at an increase of the active biomass (e.g. recirculation of reactor material, two stage processes)
    • Process inhibition (enzymatically regulated product inhibition and toxicity)
    • Improved pre-treatment to increase degradation rates and VS-reduction
    • Mixing and rheology
    • Better monitoring and control
    • Co-digestion with more high-potential substrates

    The present report reviews a number of fields that are linked to improvements in the biogas production process as based on the bullets above.

    A well-working, active biomass is a prerequisite for efficient biogas production processes, why factors affecting microbial growth are crucial to obtain stable processes at the highest possible organic load/lowest possible hydraulic retention time.

    The microorganisms need nutrients, i.e. carbon, nitrogen, phosphorus, calcium, potassium, magnesium and iron as well as trace elements such as cobalt, nickel, manganese, molybdenum, selenium and tungsten for growth. The need of nutrients and trace elements varies with the substrate digested, the organic loading rate, the process design (e.g. the reactor configuration, the degree of recirculation etc). In addition, the complexity of the chemical reactions controlling the bioavailability of the trace metals is wide, why optimal addition strategies for trace elements needs to be developed.

    Substrates as food wastes, sewage sludge, cattle manure, certain energy crops and algae are good bases to obtain processes with good nutrient- and trace element balances. These kinds of substrates can often be implemented for “mono-substrate” digestion, while substrates dominated by carbohydrates or fats needs to be co-digested or digested in processes modified by  e.g. nutrient- and trace element additions, sludge recirculation, etc. Protein-rich substrates often include enough nutrients, but can give other process problems (see below).

    Iron, cobalt and nickel are the nutrients/trace elements given most attention so far. However, molybdenum, selenium and tungsten have also, among others, been shown effective in different AD applications. The effects have, however, mainly been shown on turnover of VFAs and hydrogen (resulting in increased methane formation), while just a few studies have addressed their direct effect on rates of hydrolysis, protein-, fat- and carbohydrate degradation. Selenium- and cobalt-containing enzymes are known to be involved in amino acid degradation, while selenium and tungsten are needed in fat- and long chain fatty acid degradation. Enzymes active in hydrolysis of cellulose have been shown to be positively affected by cobalt, cupper, manganese, magnesium and calcium. This implies that trace element levels and availability will directly affect the hydrolysis rates as well as rates and degradation pathways for digestion of amino acids, long chain fatty acids and carbohydrates. However, their effect on hydrolysis seems neglected, why studies are needed to map the metals present in active sites and co-factors of enzymes mediating these primary reactions in AD. Further investigations are then needed to elucidate the importance of the identified metals on the different degradation steps of AD aiming at increased degradation rates of polymeric and complex substrates. It should also be noted that the degradation routes for amino acid degradation in AD-processes, factors governing their metabolic pathways, and how ATP is gained in the different pathways seem unknown. The different routes may result in different degradation efficiencies, why a deeper knowledge within this field is called for.

    Trace metals added to biogas reactors have positive effects on the process only if they are present in chemical species suitable for microbial uptake. Interaction of biogenic sulfide with trace metals has been identified as the main regulator of trace metal speciation during AD. Fe, Co and Ni instantaneously form strong sulfide precipitates in biogas reactors but at the same time show very different chemical speciation features. The soluble fraction of Co widely exceeded the levels theoretically possible in equilibrium with inorganic sulfide. The high level of soluble Co is likely due to association with dissolved organic compounds of microbial origin. Fe and Ni speciation demonstrated a different pattern dominated by low solubility products of inorganic metal sulfide minerals, where their solubility was controlled mainly by the interactions with different dissolved sulfide and organic ligands. To our knowledge, the information about chemical speciation of other trace metals (Se, Mo, and W among others) and its effects on the bioavailability in anaerobic digestion environments is rare. Providing information on the metal requirements by processes linked to their bioavailability in biogas reactors is identified as a key knowledge needed for maximizing the effect of metals added to biogas reactors. Further research is also needed for development and design of proper metal additive solutions for application in full scale biogas plants. A practical approach is to supplement trace metals in specific chemical forms, which are either suitable for direct bio-uptake or will hamper undesirable and bio-uptake-limiting reactions (e.g. mineral precipitation).

    Recirculation of reactor material as a way to enrich and maintain an active microbial biomass (and, thus, an increase in the substrate turnover rate) in tank reactors has been tested for digestion of fat within BRCs project DP6. The methane yield increased from 70 to 90% of the theoretical potential at a fat-loading rate of 1.5 g VS/L and day. The same strategy has been successful during digestion of fiber sludge from the pulp and paper industry, i.e. the recirculation has been crucial in establishment of low hydraulic retention times. Also degradation of sewage sludge (SS) would likely be improved by recirculation as the retention time of the solid SS is prolonged in such a system. However, this remains to be tested. The recirculation concept also needs to be evaluated in larger scale reactors to form a base to include extra costs and energy consumption vs. the benefits from increased yields.

    To divide the anaerobic digestion process into two phases, where the hydrolytic/acidogenic and the syntrophic/methanogenic stages of anaerobic digestion are separated, might be a way to enhance degradation of lignocellulosic materials as the hydrolysis of these compounds may be inhibited by the release of soluble sugars. It should be noted that the natural AD of ruminates is phase-separated and improvements in AD can likely be achieved using these natural systems as a starting point. Also the degradation of aromatic and chlorinated species is likely enhanced by phase separation. One way to obtain such systems is to combine a leached bed for hydrolysis of insoluble material with a methanogenic reactor treating the leachate. Plug flow reactors might be another possibility as well as membrane reactors, which physically separates the hydrolyzing and methanogenic phases.

    Inhibition caused by toxic levels of ammonia (protein- and ammonia rich substrates), fat-rich substrates and long chain fatty acids (LCFAs), aromatic compounds, salts etc. have been reported in many cases and some remedies are suggested. Ammonia can be stripped off as a measure to overcome too high levels. Another option is to adjust pH of the reactor liquid by addition of acid shifting the ammonia-ammonium balance in the system towards less free ammonia. A decrease in alkalinity by acid addition might also affect the availability of trace elements as solubility of trace metal mineral phases is generally higher at lower pH. LCFA degradation has been shown to benefit from periodic additions of fat and is, thus, an effective strategy to minimize inhibition by the release of the LCFA. Adsorption to zeolites has also been shown to abate the inhibition by LCFA. The best way to avoid inhibition is, however, to keep the processes nutritionally well balanced and using concepts suitable for the actual substrate mix digested (i.e. sludge recirculation, phase separation etc.) in order to obtain the highest possible degradation rate for problematic compounds, thus, avoiding accumulation of inhibitory components such as LCFA and aromatics. High ammonia and salt levels can often be regulated by the substrate mix.

    The hydrolysis is often reported as rate limiting in digestion of complex polymers in balanced anaerobic digestion systems, while the methanogensis is regarded as rate-limiting for more easily degraded substrates. As mentioned above the effect on methane formation rates by the addition of trace elements have been shown in numerous studies, while their effect on the hydrolysis and acidogenic AD steps are much less studied. Thus, the effects of the trace elements on the early steps in the AD-chain need to be investigated further.

    To obtain high-rate hydrolysis, effective and energy efficient pre-treatment methods are crucial for a large number of substrates. The rate of hydrolysis is to a large extent dependent on the properties of the organic compounds in the substrate e.g. carbohydrates, proteins, fat or lignocellulosic material as well as particle size and pre-treatment methods applied. The establishment and colonization by sessile microorganisms and biofilms is highly important for efficient and high rate hydrolysis. Microbial formation of organic compounds and the availability of surfaces are factors influencing these key processes, which in turn are tightly coupled to the growth conditions for the hydrolyzing microorganisms. This is an area recently brought up as an issue for detailed research.

    Mixing is mostly needed for effective high-rate biogas production, but too extensive mixing can destroy the syntrohpic interactions necessarily taking place during AD. However, the efficiency of the mixing system design in relation to colonization, presences of dead zones, changes in viscosity/rheology, etc. seem unclear and this area thus calls for further attention. 

    In high-loaded efficient processes a monitoring program following parameters e.g. organic loading rate, gas-production, VS-reduction, pH and VFA-levels is needed. This can be achieved through sampling and analysis off line, but there are of course benefits with on-line monitoring. A number of different methods have been suggested and tested, and some titration- and spectroscopic methods are applied, but none seems commonly in use. The reasons for the low interest to apply these methods may be the need for expertise on calibration, validation and multivariate analysis of most on-line methods, high maintenance demands (cost and time), and l functional problems related to fouling, gas bubbles, sensor location, disturbing particles etc.

    New substrates with the highest potential for use in existing or new biogas plants seem to be forestry-based biomass, certain energy crops and macro-algae. Both the energy crops and the macro-algae can be chosen to give nutritionally well balanced AD-processes, while AD on forestry biomass demands nutrient supplements. For both the energy crops and the macro-algae sustainable cultivation systems need to be developed. Crop rotation systems should be employed to minimize tillage as well as fertilization- and pesticide utilization at highest possible TS-yields. System analyses aiming at sustainability and economy of TS and methane yields per ha including needs of nutrient supplements should therefore be performed.

    In all three cases (forestry biomass, energy crops and algae) pre-treatment methods to create high internal surface areas are needed. However, the pre-treatment methods chosen need to be highly energy- and resource efficient to obtain sustainable systems (a positive energy balance). New plants will for profitability likely need to be large with highly developed infrastructure for substrates supply and distribution of the produced biogas/electricity nearby. Process concepts aiming at highest possible loading rates at shortest possible retention time will be needed, which likely are met by including both phase-separated process systems and systems for sludge recirculation.

    It should also be noted that the lignin in substrates from forestry biomass needs to be used for production of e.g. polymeric materials or as a fuel to obtain reasonable energy balances for AD of lignocellulose. Pre-treatment methods obtaining separation of lignin is therefore needed. A substantial research and development is in progress within this field.

    The possibilities for AD within the pulp and paper industry are interesting, especially if specific effluents within the pulp- and paper production units are selected and the raw material for the pulp and paper production is chosen considering the biogas yields of the residues.

  • 38.
    Larsson, Madeleine
    et al.
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Ekstrand, Eva-Maria
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Truong, Xu-bin
    Linköping University, Biogas Research Center. Scandinavian Biogas Fuels AB, Sweden.
    Nilsson, Fredrik
    Pöyry Sweden AB, Norrköping, Sweden.
    Ejlertsson, Jörgen
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center. Scandinavian Biogas Fuels AB, Sweden.
    Svensson, Bo
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Karlsson, Anna
    Linköping University, Biogas Research Center. Scandinavian Biogas Fuels AB, Sweden.
    Björn, Annika
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    The biomethane potential of chemical thermo-mechanical pulp wastewaters in relation to their chemical composition2015Manuscript (preprint) (Other academic)
    Abstract [en]

    This study evaluates the biomethane potential of composite pulping and bleaching chemical thermo-mechanical pulp (CTMP) wastewaters in relation to their composition of organic compounds, as well as to their sulphur contents. The biomethane potential was determined in batch experiments and the CTMP wastewaters from production of bleached spruce-, birch- and aspen pulp and unbleached spruce pulp were analysed for dissolved lignin, carbohydrates, wood extractives, acetic acid and total sulphur content. The biomethane potential obtained for the wastewaters ranged from 350 to 670 NmL g TOC-1 with the highest yield for wastewater from the production of bleached birch CTMP followed by bleached aspen-, bleached spruce- and unbleached spruce CTMP. The main differences in wastewater composition were related to the raw material used for the pulp production, i.e. softwood vs. hardwood. The compounds mainly promoting the biomethane production were acetic acid, xylose, wood extractives, triglycerides and steryl esters, whereas dissolved lignin, sulphur, arabinose, mannose, lignans and free fatty-/resin acids lowered the potential. However, the individual contribution of each variable was not possible to evaluate due to covariations among them.

  • 39.
    Larsson, Madeleine
    et al.
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Svedlund, Matilda
    Karlsson, Marielle
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Truong, Xu-bin
    Scandinavian Biogas Fuels AB.
    Ejlertsson, Jörgen
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Björn, Annika
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Svensson, Bo
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Karlsson, Anna
    Scandinavian Biogas Fuels AB.
    Effects of temperature on UASB digestion of wastewater from a millproducing recovered fiberbased board2015Conference paper (Refereed)
  • 40.
    Larsson, Madeleine
    et al.
    Linköping University, Department of Thematic Studies, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Truong, Xu-bin
    Scandinavian Fuels AB, Stockholm, Sweden.
    Bastviken, David
    Linköping University, Department of Thematic Studies, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Björn, Annika
    Linköping University, Department of Thematic Studies, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Ejlertsson, Jörgen
    Linköping University, Department of Thematic Studies, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Svensson, Bo H.
    Linköping University, Department of Thematic Studies, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Karlsson, Anna
    Scandinavian Fuels AB, Stockholm, Sweden.
    Anaerobic digestion of alkaline bleaching wastewater from Kraft pulp and paper mill2013In: Proceedings of 13th World Congress on Anaerobic Digestion / [ed] Juan M. Lema et al., Santiago de Compostella: Lapices , 2013Conference paper (Other academic)
  • 41.
    Larsson, Madeleine
    et al.
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Truong, Xu-bin
    Linköping University, Biogas Research Center. Scandinavian Biogas Fuels AB, Sweden.
    Björn, Annika
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Ejlertsson, Jörgen
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center. Scandinavian Biogas Fuels AB, Sweden.
    Bastviken, David
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Svensson, Bo
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Karlsson, Anna
    Linköping University, Biogas Research Center. Scandinavian Biogas Fuels AB, Sweden.
    Anaerobic digestion of alkaline bleaching wastewater from a Kraft pulp and paper mill using UASB technique2015In: Environmental technology, ISSN 0959-3330, E-ISSN 1479-487X, Vol. 36, no 12, p. 1489-1498Article in journal (Refereed)
    Abstract [en]

    Anaerobic digestion of alkaline kraft elemental chlorine-free bleaching wastewater in two mesophilic, lab-scale upflow anaerobic sludge bed reactors resulted in significantly higher biogas production (250 ± 50 vs. 120 ± 30 NmL g [Formula: see text]) and reduction of filtered total organic carbon (fTOC) (60 ± 5 vs. 43 ± 6%) for wastewater from processing of hardwood (HW) compared with softwood (SW). In all cases, the gas production was likely underestimated due to poor gas separation in the reactors. Despite changes in wastewater characteristics, a stable anaerobic process was maintained with hydraulic retention times (HRTs) between 7 and 14 h. Lowering the HRT (from 13.5 to 8.5 h) did not significantly affect the process, and the stable performance at 8.5 h leaves room for further decreases in HRT. The results show that this type of wastewater is suitable for a full-scale implementation, but the difference in methane potential between SW and HW is important to consider both regarding process dimensioning and biogas yield optimization.

  • 42.
    Larsson, Madeleine
    et al.
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Truong, Xu-bin
    Linköping University, Biogas Research Center. Scandinavian Biogas Fuels AB, Sweden.
    Björn, Annika
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Ejlertsson, Jörgen
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center. Scandinavian Biogas Fuels AB, Sweden.
    Svensson, Bo
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Bastviken, David
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Karlsson, Anna
    Linköping University, Biogas Research Center. Scandinavian Biogas Fuels AB, Sweden.
    Anaerobic digestion of wastewater from the production of bleached chemical thermo-mechanical pulp: higher methane production for hardwood than softwood2017In: Journal of chemical technology and biotechnology (1986), ISSN 0268-2575, E-ISSN 1097-4660, Vol. 2, no 1, p. 140-151Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Chemical thermo-mechanical pulp (CTMP) mills holds a large biomethane potential in their wastewater. Their broadened market has involved increased bleaching and utilisation of different raw materials. Therefore, the main aim of this study was to obtain and maintain a stable anaerobic digestion (AD) process, with a high methane yield and total organic carbon (TOC) reduction, when digesting CTMP wastewater, from different production protocols including shifts in raw material and bleaching. A lab-scale upflow anaerobic sludge bed (UASB) reactor was used for the tests.

    RESULTS: The variations in raw material (aspen, birch and spruce) and consequently in TOC-loading (3.6-6.6 kg TOC m-3 and day-1) did not affect the UASB process negatively. Methane production values from 360 to 500 NmL g TOC-1 were obtained, with the highest yield for wastewater from the production of birch- followed by aspenand spruce pulp. The acetic acid and fTOC reduction ranged 90 to 95% and 61 to 73%, respectively.

    CONCLUSIONS: The stable process performance maintained during shifts in raw material for pulp production show that AD is feasible for CTMP mills with a diversified product portfolio. Furthermore, the increased use of hardwood and bleaching will most likely increase their potential as a biomethane producer.

  • 43.
    Larsson, Madeleine
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Truong, Xu-bin
    Linköping University, Biogas Research Center. Scandinavian Biogas Fuels.
    Ejlertsson, Jörgen
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Bastviken, David
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Björn, Annika
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Svensson, Bo
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Nilsson, Fredrik
    Linköping University, Biogas Research Center. Pöyry AB.
    Karlsson, Anna
    Linköping University, Biogas Research Center. Scandinavian Biogas Fuels AB.
    Anaerobic wastewater treatment and biogas production at TMP and CTMP mills in Sweden.2014Conference paper (Refereed)
  • 44.
    Moestedt, J.
    et al.
    Linköping University, Biogas Research Center. Department of R&D Biogas, Tekniska verken i Linköping AB, Linköping, Sweden; Department of Microbiology, BioCenter, University of Agricultural Sciences, Uppsala, Sweden.
    Nordell, E.
    Linköping University, Biogas Research Center. Department of R&D Biogas, Tekniska verken i Linköping AB, Linköping, Sweden.
    Shakeri Yekta, Sepehr
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Lundgren, J.
    Linköping University, Biogas Research Center. Department of R&D Biogas, Tekniska verken i Linköping AB, Linköping, Sweden.
    Marti, M.
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Sundberg, Carina
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Ejlertsson, Jörgen
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center. Scandinavian Biogas Fuels AB, Sweden.
    Svensson, Bo
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Björn, Annika
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Effects of trace element addition on process stability during anaerobic co-digestion of OFMSW and slaughterhouse waste2016In: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456, Vol. 47, no Pt A, p. 11-20Article in journal (Refereed)
    Abstract [en]

    This study used semi-continuous laboratory scale biogas reactors to simulate the effects of trace-element addition in different combinations, while degrading the organic fraction of municipal solid waste and slaughterhouse waste. The results show that the combined addition of Fe, Co and Ni was superior to the addition of only Fe, Fe and Co or Fe and Ni. However, the addition of only Fe resulted in a more stable process than the combined addition of Fe and Co, perhaps indicating a too efficient acidogenesis and/or homoacetogenesis in relation to a Ni-deprived methanogenic population. The results were observed in terms of higher biogas production (+9%), biogas production rates (+35%) and reduced VFA concentration for combined addition compared to only Fe and Ni. The higher stability was supported by observations of differences in viscosity, intraday WA-and biogas kinetics as well as by the 16S rRNA gene and 16S rRNA of the methanogens.(c) 2015 Elsevier Ltd. All rights reserved.

  • 45.
    Moestedt, Jan
    et al.
    Linköping University, Biogas Research Center. SLU.
    Nordell, Erik
    Linköping University, Biogas Research Center. Tekniska Verken i Linköping.
    Lundgren, Jesper
    Linköping University, Biogas Research Center.
    Genero Marti, Magali
    Linköping University, Biogas Research Center.
    Sundberg, Carina
    Linköping University, Department of Thematic Studies, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Ejlertsson, Jörgen
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Svensson, Bo
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Björn, Annika
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Effects of trace element addition on process stability during anaerobic co-digestion of OFMSW and slaughterhouse waste2014Conference paper (Refereed)
  • 46.
    Moestedt, Jan
    et al.
    Linköping University, Biogas Research Center. Tekniska Verken i Linköping.
    Nordell, Erik
    Linköping University, Biogas Research Center. Tekniska Verken i Linköping.
    Shakeri Yekta, Sepehr
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Lundgren, Jesper
    Linköping University, Biogas Research Center.
    Björn, Annika
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Ejlertsson, Jörgen
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Svensson, Bo
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    The combined effects of iron, cobalt and nickel additions on anaerobicco-digestion of food and slaughterhouse waste2014Conference paper (Refereed)
  • 47.
    Ometto, F.
    et al.
    Research and Development Department , Scandinavian Biogas Fuels AB , Stockholm , Sweden.
    Berg, A.
    Research and Development Department , Scandinavian Biogas Fuels AB , Stockholm , Sweden.
    Björn, Annika
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Safaric, Luka
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Svensson, Bo H.
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Karlsson, A.
    Research and Development Department , Scandinavian Biogas Fuels AB , Stockholm , Sweden.
    Ejlertsson, Jörgen
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Research and Development Department , Scandinavian Biogas Fuels AB , Stockholm , Sweden.
    Inclusion of Saccharina latissima in conventional anaerobic digestion systems2018In: Environmental technology, ISSN 0959-3330, E-ISSN 1479-487X, Vol. 39, no 5, p. 628-639Article in journal (Refereed)
    Abstract [en]

    Loading macroalgae into existing anaerobic digestion (AD) plants allows us to overcome challenges such as low digestion efficiencies, trace elements limitation, excessive salinity levels and accumulation of volatile fatty acids (VFAs), observed while digesting algae as a single substrate. In this work, the co-digestion of the brown macroalgae Saccharina latissima with mixed municipal wastewater sludge (WWS) was investigated in mesophilic and thermophilic conditions. The hydraulic retention time (HRT) and the organic loading rate (OLR) were fixed at 19 days and 2.1 g l-1 d-1of volatile solids (VS), respectively. Initially, WWS was digested alone. Subsequently, a percentage of the total OLR (20%, 50% and finally 80%) was replaced by S. latissima biomass. Optimal digestion conditions were observed at medium-low algae loading (=50% of total OLR) with an average methane yield close to [Formula: see text] and [Formula: see text] in mesophilic and thermophilic conditions, respectively. The conductivity values increased with the algae loading without inhibiting the digestion process. The viscosities of the reactor sludges revealed decreasing values with reduced WWS loading at both temperatures, enhancing mixing properties.

  • 48.
    Shakeri Yekta, Sepehr
    et al.
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Hedenstrom, Mattias
    Department of Chemistry, Umeå University, Umeå, Sweden.
    Stehr, Jan Eric
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Dario, Mårten
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Hertkorn, Norbert
    German Res Ctr Environm Hlth, Germany.
    Björn (Fredriksson), Annika
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Pretreatment,of anaerobic digester samples by hydrochloric acid for solution-state H-1 and C-13 NMR spectroscopic characterization of organic matter2018In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 199, p. 201-209Article in journal (Refereed)
    Abstract [en]

    Pretreatment of anaerobic digester samples by hydrochloric acid (HCl) resulted in removal of Fe-based mineral and coordination compounds, attenuating their interferences with solution-state nuclear magnetic resonance (NMR) spectroscopic characterization of the solid phase organic matter. Substrate (influent) and digestate (effluent) samples from two full-scale anaerobic digesters, designated CD (co-digester) and SSD (sewage sludge digester), were investigated. Pretreatment of CD samples with 0.2-2.0 mol l(-1) HCl and pretreatment of SSD samples with 1.0-3.0 mol l(-1) HCl removed 96-100% and 76-80% of total Fe, respectively. Pretreatment declined overall paramagnetic characteristics of digestate samples, manifested by 50% (CD) and 70% (SSD) decrease in electron paramagnetic resonance signal intensities. As a result, meaningful solution-state H-1,C-13 heteronuclear single quantum coherence and H-1 NMR spectra of DMSO-d(6) soluble organic matter could be acquired. Sample pretreatment with the lowest concentration of HCl resulted in alteration of C:N ratios in solid phase, likely due to removal of labile organic and inorganic C- and N-containing compounds, while elevating the HCl concentration did not further change the C:N ratios. Furthermore, sample pretreatment increased the solubility of carbohydrates and proteins in DMSO-d(6), enabling the detection of NMR resonances from certain structural units of carbohydrates (e.g. anomeric O2CH) and proteins (e.g. CH alpha in amino acids). Both attenuation of the paramagnetic matrix as well as art enhanced solubility of carbohydrate and protein fractions of the samples in DMSO-d(6) solvent contributed to an improved molecular characterization of anaerobic digester samples by solution-state NMR analysis.

  • 49.
    Shakeri Yekta, Sepehr
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Lindmark, Amanda
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Björn, Annika
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Svensson, Bo H.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    The speciation and dynamics of Fe, Ni and Co supplemented to stillage-fed semi continuous stirred tank biogas reactors2013In: Proceedings for 13th World Congress on Anaerobic Digestion / [ed] Juan M. Lema et al., Santiago de Compostella: Lapices , 2013Conference paper (Other academic)
  • 50.
    Shakeri Yekta, Sepehr
    et al.
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Skyllberg, Ulf
    Linköping University, Biogas Research Center. Umeå Universitet.
    Björn, Annika
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Svensson, Bo
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Chemical speciation of sulfur and metals in biogas processes2014Conference paper (Other academic)
12 1 - 50 of 55
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