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  • 101.
    Kumpiene, Jurate
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Xu, Jingying
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Bäckström, Anna
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Arsenic leaching in landfilled soil2012In: Abstract proceedings of 7th Intercontinental Landfill Research Symposium: Södra Sunderbyn, June 25th to 27th, 2012 / [ed] Anders Lagerkvist, Luleå: Luleå tekniska universitet, 2012, p. 87-Conference paper (Refereed)
  • 102.
    Brännvall, Evelina
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Belmonte, Carles
    Luleå University of Technology.
    Kumpiene, Jurate
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Characterisation of waste material mixtures for landfill top cover application2012In: Abstract proceedings of 7th Intercontinental Landfill Research Symposium: Södra Sunderbyn, June 25th to 27th, 2012 / [ed] Anders Lagerkvist, Luleå: Luleå tekniska universitet, 2012, p. 54-Conference paper (Refereed)
  • 103.
    Sjöblom, Rolf
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Classification of waste as hazardous or non-hazardous: the cases of ash and slag2012In: Waste Management and the Environment VI / [ed] V. Popov; H. Itoh; C.A. Brebbia, WIT Press, 2012, p. 285-296Conference paper (Refereed)
    Abstract [en]

    Anyone who owns and manages waste is obligated by law to know if it is hazardous or non-hazardous. However, proper classification of waste from incineration and combustion facilities as well as from steel mills may initially appear as a "mission impossible". In such waste, oxides of various elements appear in the form of various phases with non-stoichiometric and varying compositions that do not appear in the data bases on hazardous properties of various substances. The trace elements - which are the ones of highest significance for the classification - do not form phases of their own but are included in the phases formed by the major elements in the form of solid solution. Different batches of waste may have different ranges of compositions rendering direct testing an insurmountable task. A method is presented by means of which such residues can be classified in a conservative but still reasonably realistic and feasible manner. According to this method, elements of interest are regarded as if they appeared as simple oxides or as mixed oxides with iron. These reference substances are selected in such a manner that they can be found in databases on hazardous properties of various substances. Such data of the reference substances can then be used together with data from chemical analysis to calculate whether the waste in question is hazardous or non-hazardous. This approach has been pursued in Sweden at more than 30 plants with good results. It is anticipated that the method - after adjustment - can be used also under upcoming new legislation

  • 104.
    Nordmark, Desiree
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Lagerkvist, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Lindgren, Elisabet
    Sundsvall Energi.
    Vamling, Maria
    Länsstyrelsen Västernorrland.
    Evaluation of methods used to reduce leaching of harmful substances from residual fly ash fraction after washing2012In: Proceedings of the Thirteenth International Symposium on Environmental Issues and Waste Management in Energy and Mineral Production / [ed] Hao Ge; Carmen Mihaela Neculita; Maria Menegaki; Anil Mehrotra, Irvine, CA, USA: The Reading Matrix Inc. , 2012Conference paper (Refereed)
    Abstract [sv]

    Korstaverken near Sundsvall in Sweden produces electricity and district heating for about 80 000 citizens. Household and commercial wastes are used as fuel in their cogeneration plant. The produced fly ash is treated in an ash washing facility to reduce leaching of hazardous substances. Leaching of chromium and molybdenum from the ash residue exceeds although the limit values for non-hazardous landfills. The aim of this project has been to identify factors that influence the leaching of chromium and molybdenum and how a reduction can be achieved. Reduced mobility can be reached by addition of pH and redox reducing agents, or by carbonation. The results show that there are a number of measures that can generate a washed ash that meets the requirements of non-hazardous landfills. In order to design the optimal full scale solution from a practical and economical perspective, the identified alternatives must be evaluated.

  • 105.
    Sjöblom, Rolf
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Cato, Anna
    Swedish Radiation Safety Authority.
    Lindskog, Staffan
    Swedish Radiation Safety Authority.
    Financial planning for the decommissioning of a nuclear power plant2012In: Environmental Impact / [ed] C.A. Brebbia, Southampton: WIT Press, 2012, p. 3-14Conference paper (Refereed)
    Abstract [en]

    After their service life is over, nuclear power plants must be decommissioned. Accordingly, Sweden has a system with segregated funds to cover the costs. Payments to the funds are dictated by the results of recurrent cost estimates. Recently, differences have been observed between different estimations for the Barsebäck BWR:s. Therefore, the Swedish Radiation Safety Authority, who oversees the system, has commissioned the present study with the objective to investigate the reasons. The work comprises analyses of generic deviances as well as specific ones. It was found that the variations are within the ranges observed elsewhere, but that the precision in comparisons between different reactors can be improved. No new cost raisers were identified for the Barsebäck reactors. It was found that the cost estimation community strongly recommends the parametric method for early estimates whilst the cost calculations on decommissioning are mostly based on the bottom-up method. It is proposed that the parametric method be attempted for comparison between different reactors

  • 106.
    Sjöblom, Rolf
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Cato, Anna
    Swedish Radiation Safety Authority.
    Lindskog, Staffan
    Swedish Radiation Safety Authority.
    Finansiella aspekter vid avveckling av kärnkraftverk (BWR)2012Report (Other academic)
    Abstract [en]

    After their service life is over, nuclear power plants must be decommissioned. Accordingly,Sweden has a system with segregated funds to cover the costs. Paymentsto the funds are dictated by the results of recurrent cost estimates.Recently, differences have been observed between different estimations for the twopermanent shut-down BWR:s at the Barsebäck site. Therefore, the Swedish RadiationSafety Authority, who oversees the system, has commissioned the present studywith the objective to investigate the reasons. The work comprises analyses of genericdeviances as well as specific ones.It was found that the variations are within the ranges observed elsewhere, but thatthe precision in comparisons between different reactors can be improved. No newcost raisers were identified for the two reactors. It was found that the cost estimationcommunity strongly recommends the parametric method for early estimates whilstthe cost calculations on decommissioning are mostly based on the bottom-up method.It is proposed that the parametric method can be attempted for comparison betweendifferent reactors.

  • 107.
    Wikström, Tommy
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Nordmark, Desiree
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Pelkonen, Markku
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Lagerkvist, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Fluorescent in situ hybridization technique in anaerobic process studies2012In: Abstract proceedings of 7th Intercontinental Landfill Research Symposium :: Södra Sunderbyn, June 25th to 27th, 2012 / [ed] Anders Lagerkvist, Luleå: Luleå tekniska universitet, 2012, p. 130-131Conference paper (Refereed)
  • 108.
    Kumpiene, Jurate
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Immobilisation of arsenic in landfilled soil using amendments2012In: Understanding the geological and medical interface of arsenic, As2012: 4th International Congress Arsenic in the Environment, Sebel Cairns International Hotel, Cairns, Australia, 22-27 July 2012 / [ed] Jack C. Ng, Boca Raton: CRC Press, 2012, p. 326-327Conference paper (Refereed)
    Abstract [en]

    The aim of the study was to assess the leaching of Arsenic (As) from chemically stabilized soil using sulfur-containing amendments under simulated landfill conditions (anaerobic environment). Three soils from former wood impregnation plants containing 270-4590 mg/kg As were mixed either with Coal Fly Ash (CFA), Calcium Sulfate (CaSO 4) or Calcium Sulfide (CaS) (3 wt% each) and incubated for one month in an anaerobic environment. None of the soil amendments were effective to reduce As leaching in anaerobic environment to the levels that were measured in aerobic conditions

  • 109.
    Andreas, Lale
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Implementing a lab-developed liner recipe in a full scale cover construction: challenges, setbacks and success2012In: Abstract proceedings of 7th Intercontinental Landfill Research Symposium: Södra Sunderbyn, June 25th to 27th, 2012 / [ed] Anders Lagerkvist, Luleå: Luleå tekniska universitet, 2012, p. 40-Conference paper (Refereed)
  • 110.
    Carabante, Ivan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Grahn, Mattias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Holmgren, Allan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Kumpiene, Jurate
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Influence of Zn(II) on the adsorption of arsenate onto ferrihydrite2012In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 46, no 24, p. 13152-13159Article in journal (Refereed)
    Abstract [en]

    Addition of iron oxide to arsenic-contaminated soil has been proposed as a means of reducing the mobility of arsenic in the soil. Arsenic and zinc are common coexisting contaminants in soils. The presence of zinc therefore may affect the adsorption properties of arsenic on iron oxide, and may thus affect its mobility in the soil. The influence of Zn(II) on the adsorption of arsenate ions on iron oxide was studied. Batch adsorption experiments indicated that Zn(II) increased the arsenate removal from a solution by ferrihydrite at pH 8. However, ATR-FTIR spectroscopy showed that no adsorption of arsenate on a ferrihydrite film occurred at pD 8 in the presence of Zn(II). Precipitation of zinc hydroxide carbonate followed by arsenate adorption onto the precipitate was found to be a plausible mechanism explaining the arsenate removal from a solution in the presence of Zn(II) at pH/pD 8. The previously suggested mechanisms attributing the enhanced removal of arsenate from solution in the presence of Zn(II) to additional adsorption on iron oxides could not be verified under the experimental conditions studied. It was also shown that at pH/pD 4, the presence of Zn(II) in the system did not significantly affect the adsorption of arsenate on ferrihydrite.

  • 111.
    Andreas, Lale
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Travar, Igor
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Lagerkvist, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Tham, Gustav
    Sweco AB.
    Leaching behaviour of ashes in a landfill cover construction2012In: Abstract proceedings of 7th Intercontinental Landfill Research Symposium: Södra Sunderbyn, June 25th to 27th, 2012 / [ed] Anders Lagerkvist, Luleå: Luleå tekniska universitet, 2012, p. 39-Conference paper (Refereed)
  • 112.
    Tan, Zhongxin
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Xiao, Gang
    School of Energy and Environment, Southeast University, Nanjing.
    Leaching characteristics of fly ash from Chinese medical waste incineration2012In: Waste Management & Research, ISSN 0734-242X, E-ISSN 1096-3669, Vol. 30, no 3, p. 285-294Article in journal (Refereed)
    Abstract [en]

    Many of the characteristics of typical medical waste ash can be found by using ash leaching experiments. The present study investigated the characteristics of fly ash derived from incineration of medical waste in China. The particle diameter of the fly ash was in the range 154-900 µm. Elemental analyses of the fly ash indicated that it contained calcium, aluminium, iron, sodium, potassium and magnesium, and that copper, lead, chromium and mercury were the dominant heavy metals it contained. As leaching time was increased the leaching concentrations of the heavy metals increased and the leaching toxicity was augmented. When the pH was neutral, the concentrations of most heavy metals in the leachate were minimum whereas when the pH was alkali or acid, the leaching toxicity was greatly enhanced. High temperature melting was found to be a good method of fixing heavy metals, and the main components of the sinter were Fe3O4, SiO2, CaSO4 and CaSiO3, etc.

  • 113.
    Pelkonen, Markku
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Yu, Wang
    Aalto University.
    Long term leachate management based on anaerobic/aerobic landfill simulator studies2012In: Abstract proceedings of 7th Intercontinental Landfill Research Symposium: Södra Sunderbyn, June 25th to 27th, 2012 / [ed] Anders Lagerkvist, Luleå: Luleå tekniska universitet, 2012, p. 103-104Conference paper (Refereed)
  • 114.
    Sjöblom, Rolf
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Lindskog, Staffan
    Swedish Radiation Safety Authority.
    Management of intergenerational environmental liabilities: example of decommissioning of nuclear research and development facilities2012In: International Journal of Sustainable Development and Planning, ISSN 1743-7601, E-ISSN 1743-761X, Vol. 7, no 2, p. 135-158Article in journal (Refereed)
    Abstract [en]

    The character is described of various prerequisites for and obstacles against fulfilment of the polluter pays principle in the case of decommissioning of old nuclear research and development (R&D) facilities, and the relevance to other areas is analyzed. Background is compiled in the areas of Swedish old nuclear R&D facilities, environmental liabilities in some areas, and legislation. Two completed decommissioning projects and two under planning are described together with some findings on planning for decommissioning and on cost estimation. Also, an example is given on developing a basis for regulation relating to small facilities. It is concluded that although the polluter pays principle is easy to understand, it may be complicated to implement, especially in cases where there is a gap in time between the operations and the decommissioning. Pitfalls may be plentiful and extensive awareness and substantial efforts are warranted for adequate funds to be available at the time when they are needed. Thus, it is essential that internationally available advice and knowledge be utilized, information exchanged, and necessary knowledge acquired. It is also important to realize that the planning is usually dictated by the needs for financial planning, and that there is a substantial difference between end of license and end of liability. A need for information exchange between different areas of technology is identified and it is hoped that the present work might contribute to such processes.

  • 115.
    Nordmark, Desiree
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Kumpiene, Jurate
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Brännvall, Evelina
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Mobility of redox sensitive elements due to organic matter in contaminated soil: bottom ash and residual waste fraction2012In: Abstract proceedings of 7th Intercontinental Landfill Research Symposium: Södra Sunderbyn, June 25th to 27th, 2012 / [ed] Anders Lagerkvist, Luleå: Luleå tekniska universitet, 2012, p. 100-101Conference paper (Refereed)
  • 116.
    Sjöblom, Rolf
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ecke, Holger
    Brännvall, Evelina
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    On the possibility of using vitrified forts as anthropogenic analogues for assessment of long-term behaviour of vitrified waste2012In: Waste Management and the Environment VI / [ed] V. Popov; H. Itoh; C.A. Brebbia, WIT Press, 2012, p. 225-236Conference paper (Refereed)
    Abstract [en]

    An information survey was conducted in the areas of natural analogues, vitrified forts, combustion technology and vitrified waste.The main purpose was to identify if vitrified stone material in hillforts might be used as anthropogenic analogues for glass containing waste.Such comparisons are needed in order for predictions to be made regarding the long-term integrity of the waste forms.The scope was to compare the chemistry as well as the processes used for the generation of the glasses. It was found that the vitrified forts contain glass material with wide variations in composition of the major elements.They cover and exceed those in the glasses made of waste with only the exception of phosphorus.Natural glasses as well as archaeological glasses show much narrower ranges of compositions, and they do not coincide with those of the glasses containing waste. Quality of heat analyses indicated that it is likely that the stone material in the forts was melted for the purpose of obtaining long-lasting structures.This narrows the range of possible processes used, and facilitates reconstruction of the ancient methods by means of testing.This, in turn, provides possibilities of comparison between ancient and modern methods, which can then be used as a basis for validation of the use of the analogue.

  • 117.
    Wang, Yu
    et al.
    School of Engineering, Aalto University, Espoo.
    Pelkonen, Markku
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Kaila, Juha
    School of Engineering, Aalto University, Espoo.
    Optimization of landfill leachate management in the aftercare period2012In: Waste Management & Research, ISSN 0734-242X, E-ISSN 1096-3669, Vol. 30, no 8, p. 789-799Article in journal (Refereed)
    Abstract [en]

    The management of sanitary landfills after closure is an important engineering, economic and sustainability issue and is referred to as the greatest unresolved landfill challenge. Most sanitary landfills are operated according to the dry tomb principle, resulting in aftercare periods of hundreds of years. To study landfill body behaviour, long-term leachate emissions were studied with anaerobic landfill simulators, and a forecast model was developed targeting the behaviour of NH4-N, COD and chlorides as a function of temperature and the L/S-ratio (liquid-to-solid). It was found that NH4-N is the decisive factor in leachate management, requiring the highest L/S-ratio (around 6) to meet the direct discharge limit values. Various scenarios were constructed to find optimal leachate management strategies both in large (waste height H = 25 m) and medium-sized landfills (H = 10 m) with corresponding temperature ranges. The results show that by minimizing the aftercare period length with leachate pre-treatment and recirculation, both sustainability and economic benefits can be achieved. The results provide new views on how to manage the long-term leachate aftercare problem. In the case of large landfills, further efforts are needed to reach stabilization within a reasonable time frame.

  • 118.
    Carlsson, My
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Pre-treatment of substrates for anaerobic digestion: potential and development needs2012Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Substrate pre-treatment has been gaining interest in anaerobic digestion (AD) as a means to increase biogas yields with nowadays more diversified substrate sources. The objective of this thesis is to identify improvement potentials and development needs within applications of substrate pretreatment in anaerobic digestion (AD) based on literature and specific examples, with special focus on the impact assessment and exemplified by the case of electroporation(EP) pre-treatment.The substrate inherent limitations to conversion of organic material to methane include content of non-biodegradable organic compounds, incorporation of biodegradable matter into recalcitrant structures and large particle size. WAS and lignocellulosic material are specific substrates that express significant substrate inherent limitations, especially WAS from WWTPs with long sludge age and lignocellulosic material with high lignin content.Improved AD performance relies on increasing operational methane yield as to approximate as much as possible the actual potential methane yield of the substrate at the highest possible digestion rate. This could potentially be achieved by the application of a pre-treatment, via the mechanisms of particle size reduction/solubilisation of biodegradable/bioavailable matter and/or conversion/exposure of non-biodegradable/non-bioavailable matter as to make it available or degradable. Pre-treatment mechanisms that could potentially counteract these effects are the removal of organic matter and/or the formation of refractory compounds. Pre-treatment by electroporation has the potential to affect substrates and, in some cases improve AD process performance. However, the effect of a specific pre-treatment may differ depending on the type of substrate upon which it is applied. The assessment of pre-treatment effects may be performed on different levels, representing impacts from micro to macro scale. On a substrate level, COD solubilisation is commonly measured, but the interpretation is aggravated by the application of different measurement approaches. In addition, solubilisation of COD as a result of pre-treatment does not necessarily translate into increased operational methane yield, and vice versa, the increased operational yield is not necessarily caused by increased COD solubilisation. On an AD process performance level, BMP tests have been used to assess both increased biodegradability and increased rate of degradation. Both applications rely on appropriate set-up as well as understanding of the limitations of the test. Substrate pre-treatment affects the quality of the outputs as well as the downstream processes of an AD process. A systematic approach is therefore necessary to understand how the introduction of a pre-treatment process as well as the changes in process performance with respect to qualities and quantities of outputs affect the balances of the system with respect to assessment bases such as energy, CO2 or economics.Several areas that would gain from further development can be identified within the area of substrate pre-treatment. These include improved understanding of substrate characteristics with improved descriptors, such as improved understanding of COD composition, and of BMP applicability and limitations. In addition, improved understanding of the relationship between substrate composition and process performance would be helpful to improve the understanding of different pre-treatment effects.Improved understanding of system effects where case-specific conditions can be considered is necessary for the full-scale implementation of pre-treatments to a larger extent. The application of tools for systems analysis to systems including pre-treatment should be further evaluated and a sensitivity analysis with respect to which specific conditions may render pre-treatments beneficial or non-beneficial should be performed.The practical applicability of electroporation pre-treatment for different substrates needs further development and the energy efficiency of the pre-treatment should be evaluated considering upscaling effects.

  • 119.
    Lagerkvist, Anders
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Dahlén, Lisa
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Solid Waste Generation and Characterization2012In: Encyclopedia of Sustainability Science and Technology, New York: Encyclopedia of Global Archaeology/Springer Verlag, 2012, p. 10000-10013Chapter in book (Refereed)
    Abstract [en]

    Waste is generated in all processes. According to the laws of thermodynamics , materials and energy can be transformed but never destroyed. Even if material is substantially transformed, all matter which is introduced in any kind of process will come out of the process in exactly the same number of kilograms, either as products, by-products , or waste. Waste may be solid, liquid, or gaseous. In many cases, gaseous waste is a dominating outflow when processing solid matter. However, the focus in this article is on solid waste.Waste is often perceived as the remains from consumption. However, the major part of all solid waste is generated already by consumers' demand for products, i.e., before the products were consumed and thrown away. In general, the extraction of natural resources and industrial production processes produce massively more solid waste than the consumer products amount to, e.g., about 20 times according to European waste data [14]. As material flows through society, waste is formed in each step, as illustrated in Fig. 1. The material wastes can either end up in landfills or they can be dispersed in water, air, or soil. The dispersion in liquid phases typically exits the material from the waste management domain and turns it into pollution, albeit solid wastes can also form pollution, such as the floating plastic of the oceans.

  • 120.
    Wang, Y.
    et al.
    Lahti Center, School of Science and Technology, Aalto University.
    Pelkonen, Markku
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Kaila, J.
    Lahti Center, School of Science and Technology, Aalto University.
    Strategies to enhance the biological nitrogen removal of high-strength ammonium and low C/N landfill leachate with the SBR process2012In: Environmental technology, ISSN 0959-3330, E-ISSN 1479-487X, Vol. 33, no 5, p. 579-588Article in journal (Refereed)
    Abstract [en]

    The treatment of high ammonium-nitrogen concentration landfill leachate has become an increasing problem because of the requirements to reduce nutrient emissions. A laboratory-scale sequential batch reactor (SBR) was operated and tested in order to optimize the operational strategies of a cost-saving method to enhance the removal of ammonium-nitrogen from a real landfill leachate. Two sequence schemes were tested, one with long non-aerated/aerated sequences and another with short sequences. The air supply levels with low to intermediate dissolved oxygen (DO) and external carbon addition were altered. With both schemes a high ammonium reduction (>99%) and a reasonable total nitrogen (TN) reduction (around 60%) could be achieved with strong carbon limitation (BOD 7/N=1.1). Chemical oxygen demand (COD) removal was lower with longer sequences. Denitrification via nitrite seemed to be an important part of TN removal, controlled with the low DO. With increasing nitrite accumulation COD/N removed decreased in both schemes indicating clearly a more efficient use of COD. The scheme with short sequences indicated advantages to save the air supply preventing nitrite oxidation under low air supply conditions and better TN and COD removal efficiencies. The results show that an applicable operational strategy can be found resulting in a reasonable pre-treatment option in landfills, requiring less carbon and aeration energy.

  • 121.
    Carlsson, My
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Lagerkvist, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Morgan-Sagastume, Fernando
    AnoxKaldnes AB.
    The effects of substrate pre-treatment on anaerobic digestion systems: a review2012In: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456, Vol. 32, no 9, p. 1634-1650Article in journal (Refereed)
    Abstract [en]

    Focus is placed on substrate pre-treatment in anaerobic digestion (AD) as a means of increasing biogas yields using today’s diversified substrate sources. Current pre-treatment methods to improve AD are being examined with regard to their effects on different substrate types, highlighting approaches and associated challenges in evaluating substrate pre-treatment in AD systems and its influence on the overall system of evaluation. WWTP residues represent the substrate type that is most frequently assessed in pre-treatment studies, followed by energy crops/harvesting residues, organic fraction of municipal solid waste, organic waste from food industry and manure. The pre-treatment effects are complex and generally linked to substrate characteristics and pre-treatment mechanisms. Overall, substrates containing lignin or bacterial cells appear to be the most amendable to pre-treatment for enhancing AD. Approaches used to evaluate AD enhancement in different systems is further reviewed and challenges and opportunities for improved evaluations are identified.

  • 122.
    Sjöblom, Rolf
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Noläng, Bengt
    BenSystems.
    Why trace elements are often immobilized in ashes and slags: On the role of solid solution in iron (hydr)oxides2012In: Abstract proceedings of 7th Intercontinental Landfill Research Symposium: Södra Sunderbyn, June 25th to 27th, 2012 / [ed] Anders Lagerkvist, Luleå: Luleå tekniska universitet, 2012, p. 114-115Conference paper (Refereed)
  • 123.
    Xiao, Gang
    et al.
    State Key Laboratory of Clean Energy Utilization, Zhejiang University.
    Jin, Baosheng
    Thermo-Energy Engineering Research Institute, School of Energy and Environment, Southeast University, Nanjing.
    Ni, Mingjiang
    State Key Laboratory of Clean Energy Utilization, Zhejiang University.
    Cen, Kefa
    State Key Laboratory of Clean Energy Utilization, Zhejiang University.
    Tan, Zhongxin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    A steam dried municipal solid waste gasification and melting process2011In: Frontiers of Environmental Science & Engineering in China, ISSN 1673-7415, E-ISSN 1673-7520, Vol. 5, no 2, p. 193-204Article in journal (Refereed)
    Abstract [en]

    Considering high-moisture municipal solid waste (MSW) of China, a steam dried MSW gasification and melting process was proposed, the feasibility was tested, and the mass and energy balance was analyzed. Preliminary experiments were conducted using a fixed-bed drying apparatus, a 200 kg per day fluidized-bed gasifier, and a swirl melting furnace. Moisture percentage was reduced from 50% to 20% roughly when MSW was dried by slightly superheated steam of 150A degrees C-350A degrees C within 40 min. When the temperature was less than 250A degrees C, no incondensable gas was produced during the drying process. The gasifier ran at 550A degrees C-700A degrees Cwith an air equivalence ratio (ER) of 0.2-0.4. The temperature of the swirl melting furnace reached about 1240A degrees C when the gasification ER was 0.3 and the total ER was 1.1. At these conditions, the fly ash concentration in the flue gas was 1.7 g center dot(Nm(3))(-1), which meant over 95% fly ash was trapped in the furnace and discharged as slag. 85% of Ni and Cr were bound in the slag, as well as 60% of Cu. The mass and energy balance analysis indicates that the boiler heat efficiency of an industrial MSW incineration plant reaches 86.97% when MSW is dried by steam of 200A degrees C. The boiler heat efficiency is sensitive to three important parameters, including the temperature of preheated MSW, the moisture percentage of dried MS Wand the fly ash percentage in the total ash.

  • 124.
    Brännvall, Evelina
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Andreas, Lale
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Sjöblom, Rolf
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Travar, Igor
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Kumpiene, Jurate
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Lagerkvist, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ageing of ashes in a landfill top cover2011In: SARDINIA 2011: Thirteenth International Waste Management and Landfill Symposium, S. Margherita di Pula, Cagliari, Italy; 3 - 7 October 2011 / [ed] Raffaello Cossu, Cagliari: CISA Publisher, Italy , 2011Conference paper (Refereed)
    Abstract [en]

    This paper is based on studies on the effects of accelerated ageing on refuse-derived-fuel (RDF) fly ashes, in experiments under controlled laboratory conditions, intended to derive models to predict the stability of RDF fly ashes used in a landfill liner and the mineralogi-cal changes that occur in them. A reduced factorial design was applied, followed by multivariate data analysis, to evaluate the effects of five factors — carbon dioxide (CO2) levels, temperature, relative air humidity (RH), time and the quality of added water — on mineral transformations within the ashes, and leaching behaviour. The pH values of these ash specimens ranged from 7.2 to 7.6, indicating advanced carbonation. Ageing decreased pH values from 12.4 to 7.2, conse-quently affecting the leaching behaviour of most chemicals measured in the leachates. Levels of Ba, Ca, Cl, Cr, Cu, Pb, K and Na decreased over the study period while those of Mg, Zn and SO4 increased. Clay minerals could not be detected neither in fresh nor in aged ashes. However, geo-chemical modelling indicated that such minerals may precipitate.

  • 125.
    Kumpiene, Jurate
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Mench, Michel
    UMR BIOGECO INRA 1202, Ecology of Communities, Bordeaux 1 University.
    Bes, Clémence M.
    UMR BIOGECO INRA 1202, Ecology of Communities, Bordeaux 1 University.
    Fitts, Jeffrey P.
    Energy, Environment & National Security, Environmental Sciences Department, Brookhaven National Laboratory, Upton, NY.
    Assessment of aided phytostabilization of copper-contaminated soil by X-ray absorption spectroscopy and chemical extractions2011In: Environmental Pollution, ISSN 0269-7491, E-ISSN 1873-6424, Vol. 159, no 6, p. 1536-1542Article in journal (Refereed)
    Abstract [en]

    Field plots were established at a timber treatment site to evaluate remediation of Cu contaminated topsoils with aided phytostabilization. Soil containing 2600 mg kg-1 Cu was amended with a combination of 5 wt% compost and 2 wt% iron grit, and vegetated. Sequential extraction was combined with extended X-ray absorption fine structure (EXAFS) spectroscopy to correlate changes in Cu distribution across five fractions with changes in the predominant Cu compounds two years after treatment in parallel treated and untreated field plots. Exchangeable Cu dominated untreated soil, most likely as Cu(II) species non-specifically bound to natural organic matter. The EXAFS spectroscopic results are consistent with the sequential extraction results, which show a major shift in Cu distribution as a result of soil treatment to the fraction bound to poorly crystalline Fe oxyhydroxides forming binuclear inner-sphere complexes.

  • 126.
    Kumpiene, Jurate
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Robinson, Ryan
    Brännvall, Evelina
    Nordmark, Desiree
    Bjurstöm, Henrik
    ÅF-Engineering AB.
    Andreas, Lale
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Lagerkvist, Anders
    Ecke, Holger
    Carbon speciation in ash, residual waste and contaminated soil by thermal and chemical analyses2011In: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456, Vol. 31, no 1, p. 18-25Article in journal (Refereed)
    Abstract [en]

    Carbon in waste can occur as inorganic (IC), organic (OC) and elemental carbon (EC) each having distinct chemical properties and possible environmental effects. In this study, carbon speciation was performed using thermogravimetric analysis (TGA), chemical degradation tests and the standard total organic carbon (TOC) measurement procedures in three types of waste materials (bottom ash, residual waste and contaminated soil). Over 50% of the total carbon (TC) in all studied materials (72% in ash and residual waste, and 59% in soil) was biologically non-reactive or EC as determined by thermogravimetric analyses. The speciation of TOC by chemical degradation also showed a presence of a non-degradable C fraction in all materials (60% of TOC in ash, 30% in residual waste and 13% in soil), though in smaller amounts than those determined by TGA. In principle, chemical degradation method can give an indication of the presence of potentially inert C in various waste materials, while TGA is a more precise technique for C speciation, given that waste-specific method adjustments are made. The standard TOC measurement yields exaggerated estimates of organic carbon and may therefore overestimate the potential environmental impacts (e.g. landfill gas generation) of waste materials in a landfill environment.

  • 127.
    Wang, Yu
    et al.
    Lahti Center, School of Science and Technology, Aalto University.
    Pelkonen, Markku
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Kaila, J.
    Lahti Center, School of Science and Technology, Aalto University.
    Cost-saving biological nitrogen removal from strong ammonia landfill leachate2011In: Waste Management & Research, ISSN 0734-242X, E-ISSN 1096-3669, Vol. 29, no 8, p. 797-806Article in journal (Refereed)
    Abstract [en]

    The aim of the study was to develop an improved management mode in Ammassuo landfill (Finland) for leachate ammonium-nitrogen removal, to minimize the leachate management costs and secure compliance with the uptrend requirements of regulations for on-site leachate management. With a single sequential batch simulation reactor, the minimum C/N ratio was detected as 1.7 (adjusted by external carbon addition), to achieve the acceptable removal efficiency of 99, 62 and 74% in NH(4)-N, total nitrogen and chemical oxygen demand, respectively. Both total nitrogen removal and efficiency of carbon use were correlated with an increasing NO(2)(-)/NO(x)(-) ratio indicating higher performance with denitrification via nitrite. It was estimated that the leachate management cost could be reduced by 28 to 38%.

  • 128.
    Lindskog, Staffan
    et al.
    Swedish Radiation Safety Authority.
    Sjöblom, Rolf
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Division of nuclear liabilities between different license holders and owners2011In: Proceedings of the ASME 2011 14th International Conference on Environmental Remediation and Radioactive Waste Management: ICEM2011 : September 25-29, 2011, Reims, France., New York: American Society of Mechanical Engineers , 2011, Vol. PARTS A AND B, p. 985-994Conference paper (Refereed)
    Abstract [en]

    Sweden was one of the first six countries to build and operate a nuclear power reactor. Thus, there exists a corresponding legacy in terms of liabilities for decommissioning and waste management of the historic facilities. Compliance with the Polluter Pays Principle (PPP) and its corollary on equity between generations implies that plans for decommissioning must be made and funds set aside for its execution. The need for precision in the cost estimates often governs the timing of the technical planning. Cost estimates are treacherous since cost raisers may be identified and evaluated only after considerable efforts have been made. Further complications and challenges arise as a result of changes that take place between construction and decommissioning of facilities in terms of the entities involved as owners, operators, license holders, Authorities and financiers. From this perspective, the present paper summarizes the general legislation as well as the legislation that applies particularly to nuclear activities. It also summarizes the relation between the nuclear decommissioning fund system and financial reporting. Three examples are provided that wholly or partially fall under the Studsvik act (that specifically covers old facilities): The Ågesta nuclear power plant The Ranstad uranium mining and beneficiation facility The Neutron Research Laboratory at Studsvik The findings include the following: It is important that the legislation be clear as to what is included and not. The rationale for the legislation should also be clear and well communicated. Old agreements can be significant for the assessment of liabilities, even in cases where a party may no longer exist. Support for assessment of when activities are continuing or not (which may have a strong significance for the liability) can be found in court cases on chemically contaminated soil. Analysis of facilities and the work carried out at different times can be very helpful in determining whether or not a facility is auxiliary. In order to be essentially correct, annual reporting must be coherent with the declarations of the funding system and in compliance with the IAR/IFRS standards. Keeping of searchable records is essential Research is essential, not only to provide bases for high quality decisions, but also to promote consensus based on agreement on factual circumstances

  • 129.
    Vestin, Jenny
    et al.
    Statens Geotekniska Institut.
    Arm, Maria
    Statens Geotekniska Institut.
    Nordmark, Desiree
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Hallgren, Per
    Skogsstyrelsen.
    Tiberg, Charlotta
    Statens Geotekniska Institut.
    Lagerkvist, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Lind, Bo
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Effektivt askutnyttjande i vägar2011Report (Other academic)
    Abstract [sv]

    Två provsträckor, uppgraderade med olika mängd aska, utvärderades med avseende på ask-grusblandningens homogenitet och skillnader mellan de båda sträckorna. Askgrusblandningens homogenitet varierade i vägen även om den förväntade askhalten uppnåddes i medeltal. Packningsgraden blev lägre än förväntat vilket visar på vikten av omsorgsfull vattning och packning. Provsträckan med störst askhalt hade högst styvhet.

  • 130.
    Nordmark, Desiree
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Lagerkvist, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Vestin, Jenny
    Sveriges Geotekniska Institut.
    Arm, Maria
    Sveriges Geotekniska Institut.
    Lind, Bo
    Sveriges Geotekniska Institut.
    Hallgren, Per
    Skogsstyrelsen.
    Environmental and mechanical assessment of wood fly ash used for stabilisation of gravel roads2011In: SARDINIA 2011: Thirteenth International Waste Management and Landfill Symposium; [3 - 7 October 2011, S. Margherita di Pula - Cagliari, Sardinia, Italy] ; CD-ROM: Proceedings / [ed] Raffaello Cossu, Cagliari: CISA Publisher, Italy , 2011Conference paper (Refereed)
    Abstract [en]

    Due to climate change, there is a growing demand for mechanically stabilising forestry roads in Sweden. One way to do this is by addition of cement to the bearing layer of the road. In this study, cement was replaced by a forestry industry fly ash. Mechanical testing showed that a good stabilising effect could be achieved and at a 30% ash addition, it could resist more than 12 freeze-thaw cycles. The environmental impact of the ash addition was assessed using a standard leaching test at a liquid to solid ration of ten. The results indicated that most constituents of the ash remained fairly stable, but that notably chloride, potassium, calcium and sodium was mobilised in the grams per kg of TS range, adding up to about 1 % of the total mass. This may cause an elevated salinity in the emediate vicinity of a road, e g in the ditches, under a short time period, but is not considered to be a major problem for recipients. The results also indicate that the total content is a poor estimate for the leachability of various elements.

  • 131.
    Lidelöw, Sofia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Leaching behaviour of air-cooled blast-furnace slag under intermittent and continuous wetting2011Report (Other academic)
    Abstract [en]

    Air-cooled blast-furnace slag is commonly utilised as a construction material in roads, fill and embankments. Materials used in such constructions do not remain continuously wetted, but is often subjected to cyclic wetting and drying under various exposure conditions. However, its leaching behaviour is often assessed based on tests performed under continuous wetting. This work was conducted to evaluate the leaching behaviour of an air-cooled blast-furnace slag under intermittent and continuous wetting. Four different leaching tests were performed, including a static leaching test without leachant renewal and three dynamic leaching tests: a column leaching test with continuous flow of the leachant, a tank leaching test with sequential renewal of the leachant and an intermittent leaching test with periodical flow of leachant. Leaching of the studied material under cyclic wetting and drying led to less alkaline and more oxidised eluates than leaching under continuously wetted conditions. The eluates are expected to maintain a mildly alkaline pH for long time periods during wetting, drying and oxidation of the material because the material has considerable acid neutralising potential. The leaching of soluble elements such as Ca and S was lower under intermittent than under continuous flow of the leachant which could be due to the shorter contact time between the leachant and material, and the precipitation of secondary phases on the particle surfaces during intermittent leaching. During exposure of the BFS to cyclic wetting and drying, the leaching of these elements decreased and the speciation of S in the eluates shifted towards more oxidising forms. The leached amounts of constituents were low in all performed tests, which indicate that the material was resistant to leaching under the conditions that were investigated here.

  • 132. Nordmark, Desiree
    et al.
    Kumpiene, Jurate
    Andreas, Lale
    Lagerkvist, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Mobility and fractionation of arsenic, chromium and copper in thermally treated soil2011In: Waste Management & Research, ISSN 0734-242X, E-ISSN 1096-3669, Vol. 29, no 1, p. 3-12Article in journal (Refereed)
    Abstract [en]

    Thermal treatment is used to remediate soil co-contaminated with organic and inorganic contaminants. It destroys organic contaminants, but the remaining inorganic contaminants require further treatment. In this study the effects of thermal treatment on the mobility, speciation and chemical fractionation of As, Cr and Cu in a CCA-polluted soil were evaluated by leaching tests, As speciation assays and a sequential extraction procedure. The soil was sieved into four size fractions (<0.125, 0.125—0.250, 0.250—0.500 and 0.500—1.0 mm), each of which was treated at 800°C and analysed in comparison with the untreated soil. The leaching of As and Cr increased by factors of 18—40 and 2—23, respectively, while the mobility of Cu decreased 12—14-fold after treatment. The concentration of As(V) in pore water of the finest soil fraction increased 19-fold, whereas that of As(III) remained constant. The treatment reduced As, Cr and Cu associated with the reducible soil fraction. In addition, it increased the proportions of As and Cr (slightly) associated with the exchangeable and acid-soluble soil fractions, and the proportions of Cu and Cr (substantially) associated with the residual fraction.

  • 133.
    Windt, Laurent De
    et al.
    Ecole des Mines de Paris.
    Dabo, David
    Ecole des Mines de Paris.
    Lidelöw, Sofia
    Badreddine, Rabia
    INERIS, Wastes and Contaminated Sites Unit.
    Lagerkvist, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    MSWI bottom ash used as basement at two pilot-scale roads: comparison of leachate chemistry and reactive transport modeling2011In: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456, Vol. 31, no 2, p. 267-280Article in journal (Refereed)
    Abstract [en]

    The recycling of municipal solid waste incineration bottom ash as aggregates for road basement requires assessing the long-term evolution of leachate chemistry. The Dåva (Sweden) and Hérouville (France) pilot-scale roads were monitored during 6 and 10 years, respectively. Calculated saturation indices were combined to batch test modeling to set a simplified geochemical model of the bottom ash materials. A common reactive transport model was then applied to both sites. At Hérouville, pH and the concentration of most elements quickly drop during the first two years to reach a set of minimum values over 10 years. The decrease is less pronounced at Dåva. The evolutions of pH and major element concentrations are fairly well related to the following pH-buffering sequence: portlandite, C-S-H phases or pseudo-wollastonite and, finally, calcite in equilibrium with atmospheric CO2. Al(OH)3, barite, ettringite and monohydrocalcite may also control leachate chemistry. Cu release is correctly modeled by DOM complexation and tenorite equilibrium. Temperature has no significant effect on the modeling of leachate chemistry in the range 5-30 °C, except at high pH. Effects at road edges and roadside slopes are important for the release of the less reactive elements and, possibly, for carbonation processes.

  • 134. Tan, Zhongxin
    et al.
    Lagerkvist, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Phosphorus recovery from the biomass ash: a review2011In: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 15, no 8, p. 3588-3602Article in journal (Refereed)
    Abstract [en]

    Biomass ash, generated during the thermal chemical conversion of biomass for energy production, is an industrial by-product which is often recognized as a solid waste, but there are some useful elements in the biomass ash such as phosphorus, etc. So through some technology and methods, the biomass ash can be transferred into a useful resource. The paper mainly includes the following aspects: biomass ash composition characteristics, biomass thermal chemical conversion for phosphorus and phosphorus recovery technology from biomass ash. Through these aspects literature review, not only the whole biomass ash characteristics was made clear, but also we think that the idea of phosphorus from biomass ash is feasible, especially for some high phosphorus ash such as sludge ash, meat and bone meal (MBM) ash, etc. So the review about phosphorus from the biomass ash is very important practical significance for biomass energy, biomass ash disposal and phosphorus resource.

  • 135.
    Brännvall, Evelina
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Kumpiene, Jurate
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Potential mobility of trace elements in soil as affected by organic matter and redox conditions2011In: 11th International Conference on the Biogeochemistry of Trace Elements, Florence, Italy July 3-7, 2011, 2011Conference paper (Refereed)
  • 136.
    Nordmark, Desiree
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Lindgren, Elisabet
    Sundsvall Energi.
    Vamling, Maria
    Sundsvall Energi.
    Lagerkvist, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Processoptimering av asktvätt2011Report (Other academic)
    Abstract [sv]

    Asktvätten vid Korstaverket i Sundsvall producerar en tvättad aska som består av en blandning av fallande flygaska och vattenreningsslam. I tvätten avskiljs framför allt lättlösliga salter och en mobil fraktion av andra ämnen. De senare avskiljs till större delen i den efterföljande vattenreningen vars slam blandas med fallande aska i tvätten. Blandningen klarar krav för deponiklass II med undantag för utlakning av krom och molybden, för vilka dispens har erhållits upp till tre gånger gränsvärdet, som är 10 mg/kg TS. I här rapporterat projekt har syftet varit att identifiera de faktorer som påverkar främst kroms och molybdens mobilitet i den tvättade askan (dvs flygaska + slam) och hur den kan påverkas praktiskt. Resultaten kan vara av intresse för dem som söker alternativ för askhantering. I Sverige har ingen motsvarande undersökning utförts tidigare. Molybden och andra grundämnen som bildar oxyanjoner tenderar att bli mer mobila vid högre pH-värden och därför kan tillsatser till asktvätt och reningsprocess som sänker pH mot neutrala värden ge en lägre utlakning. I synnerhet molybden mobiliseras ur reningsslammet vid kontakt med den mera basiska askan, och därför kan en separat deponering av tvättad aska och slam vara ett sätt att minska den totala utlakningen. För att reducera Cr6+ till trevärd krom och därmed minska kroms mobilitet, har tillsatser av elementärt och tvåvärt järn används. Tvåvärt järn har även testats i full skala under en kort tid. I lab har både elementärt järn och tvåvärt järn visat sig ge tydligt lägre kromlakning, elementärt järn var effektivast. I full skala användes tvåvärt järn, men resultatet var inte entydigt. Här kan det tänkas att järnskrot från bottenaska skulle kunna användas. Den effektivaste tillsatsen, som dock bara testats i lab var koldioxid, tillsatsen reducerade både krom- och molybdenutlakningen. Här kan man tänka sig att använda koldioxid från förbränningsanläggningen, eller driva en efterbehandling med deponigas. Våra resultat visar att det genom olika åtgärder, eller kombinationer av åtgärder, går att producera en tvättad aska som väl uppfyller de krav på utlakning som används för en klass II deponi idag. Därmed är projektets mål uppnådda. För att utforma den praktiskt och ekonomiskt mest optimala lösningen behöver de identifierade alternativen utvärderas.

  • 137. Rastas Amofah, Lea
    et al.
    Maurice, Christian
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Kumpiene, Jurate
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Prosun, Bhattacharya
    Department of Land and Water Resources Engineering, Royal Institute of Technology, Sverige.
    Projekt: Pilotskale utvärdering av jordtvätt för sanering av arsenik-kontaminerad jord2011Other (Other (popular science, discussion, etc.))
    Abstract [sv]

    Jordtvätt - en lämplig metod för behandling av CCA förorenad jord? I samband med Länsstyrelsernas kartläggning av förorenade områden har upptäckts objekt som är förorenade med arsenik. En del av objekt är så förorenade att de har negativ påverkan på miljön eller människors hälsa så att de behöver åtgärdas senast år 2010. I träimpregneringsindustrin användes kromerad koppar arsenat (CCA) som impregneringsmedel. Olika steg i impregneringsprocessen har lett till att jord förorenats med As. Deponering är idag en vanlig metod att omhänderta arsenikförorenad jord och en betydande del av efterbehandlingskostnaderna består ofta av transport- och deponeringsavgifter. Nyligen har regelverk för bedömning av avfall förändrats vilket har banat väg för nya behandlingsmetoder för förorenad jord såsom jordtvätt. Huvudsyftet med detta projekt är att bedöma om jordtvätt är en lämplig behandlingsmetod för CCA-förorenad jord. Andra syften med projektet är att hitta en lämplig kemikalietillsats för att höja metodens effektivitet samt att hitta en effektiv metod att behandla As förorenad tvättvätska. Kan man säkerställa att den behandlade jorden är stabil och inte har några negativa effekter på omgivningen kan det bidra till att etablera jordtvätt som en hållbar behandlingsmetod. Deponering av jord är varken en hållbar eller en effektiv användning av resurser. Behandling av föroreningarna och återanvändning av det behandlade jordmaterialet kan däremot leda till minskad förbrukning av jord, minskade transporter, etc.

  • 138.
    Kumpiene, Jurate
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Brännvall, Evelina
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Taraškevičius, Ričardas
    Institute of Geology and Geography, Nature Research Centre.
    Aksamitauskas, Česlovas
    Vilnius Gediminas Technical University.
    Zinkutė, Rimantė
    Institute of Geology and Geography, Nature Research Centre.
    Spatial variability of topsoil contamination with trace elements in Preschools in Vilnius, Lithuania2011In: Journal of Geochemical Exploration, ISSN 0375-6742, E-ISSN 1879-1689, Vol. 108, no 1, p. 15-20Article in journal (Refereed)
    Abstract [en]

    An investigation of the spatial variability of topsoil contamination level was performed in 49 preschool playgrounds located in Vilnius city and correlated with urban (height and age of the preschools and height of surrounding buildings) and natural (altitude) factors. Composite samples, consisting of 20-30 sub-samples, were collected from 10 cm topsoil layer with a 3-5 m distance from each other. Sieved fraction (< 0.63 mm) was ashed at 400 °C, ground to < 1.0 μm and analysed for the real total concentrations of 22 trace elements (Ag, B, Ba, Co, Cr, Cu, Ga, Li, Mn, Mo, Nb, Ni, Pb, Sc, Sn, Sr, Ti, V, Y, Yb, Zn and Zr) using optical atomic emission spectrophotometry. Information on construction year and height (number of building stories) of preschool and surrounding buildings was acquired from the Centre of Registers of Lithuania. Out of 22 analysed elements, 13 to a greater extent exceeded the background values in several areas and were used to calculate the total contamination index (Zs13). Out of 49 analysed areas, 21 had moderately hazardous to hazardous levels of contamination as indicated by Zs13. The main contaminating elements, exceeding the permissible concentrations were Ag, Cu, Mo, Pb, Sn and Zn, the origins of which coincide with city industry and traffic. Topsoil around the newer preschool buildings, despite their location, contained lower concentrations of contaminants, while areas at higher altitudes were more contaminated than those located at lower altitudes. The latter causality is biased, as the city industry, and hence the highest contamination, is in districts located higher above sea level than the remaining studied sites.

  • 139.
    Uibu, Mai
    et al.
    Laboratory of Inorganic Materials, Tallinn University of Technology.
    Kuusik, Rein
    Laboratory of Inorganic Materials, Tallinn University of Technology.
    Andreas, Lale
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Kirsimäe, Kalle
    Department of Geology, University of Tartu.
    The CO2-binding by Ca-Mg-silicates in direct aqueous carbonation of oil shale ash and steel slag2011In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 4, p. 925-932Article in journal (Refereed)
    Abstract [en]

    This study was focused on carbonation of waste materials having low water-solubility in which Ca and Mg are generally bound as silicates. Here, pulverized firing oil shale ash (PFA from Narva Power Plants, Estonia), electric arc furnace slag (EAFS, types 1 and 2 from Uddeholm Tooling, Sweden) and ladle slag (LS from Uddeholm Tooling, Sweden) were studied as sorbents for binding CO2 from flue gases in direct aqueous mineral carbonation process. The experiments were carried out at room temperature and atmospheric pressure. Results showed that Ca-Mg-silicate phases bound up to 9 g of CO2 per 100 g of initial ash, which formed 30% of the total CO2 bound in direct aqueous carbonation of PFA. The CO2 uptakes for steel slags (EAFS1, EAFS2 and LS) were 8.7g CO2/100 g EAFS1, 1.9 g CO2/100 gEAFS2 and 4.6 g/100g LS. Quantitative XRD analysis indicated that Ca2SiO4 and Ca3Mg(SiO4)2 were the main CO2 binding low solubility components of oil shale ash as well as steel slags. The main carbonation product was calcite (CaCO3), indicating that Mg-compounds were not reactive towards CO2 at these mild conditions. Based on multifaceted studies on carbonation of oil shale ash, a new method for eliminating CO2 from flue gases by Ca-containing waste material was proposed. The process includes contacting the aqueous suspensions of Ca-containing waste material with CO2 containing flue gas in two steps: in the first step the suspension is bubbled with flue gas keeping the pH levels in the range of 10-12 and in the second step keeping the pH levels in the range of 7-8. The water-soluble components such as free lime are carbonated in the first step and the components of low solubility, in which Ca is generally contained in the form of silicates, are carbonated in the second step.

  • 140.
    Amofah, Lea Rastas
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Maurice, Christian
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Kumpiene, Jurate
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Bhattacharya, Prosun
    Department of Land and Water Resources Engineering, Royal Institute of Technology.
    The influence of temperature, pH/molarity and extractant on the removal of arsenic, chromium and zinc from contaminated soil2011In: Journal of Soils and Sediments, ISSN 1439-0108, E-ISSN 1614-7480, Vol. 11, no 8, p. 1334-1344Article in journal (Refereed)
    Abstract [en]

    Purpose: Normal soil washing leave high residual pollutant content in soil. The remediation could be improved by targeting the extraction to coarser fractions. Further, a low/high extraction pH and higher temperature enhance the pollutant removal, but these measures are costly. In this study, the utility of NaOH, oxalate-citrate (OC) and dithionite-citrate-oxalate (DCO) solutions for extracting of arsenic, chromium and zinc from contaminated soil were assessed and compared. In addition the effects of NaOH concentration and temperature on NaOH extractions, and those of temperature and pH on OC and DCO extractions, were evaluated. Materials and methods: A two-level, full-factorial design with a centre point was implemented. Two factors, concentration and temperature,were evaluated in NaOH extractions, and pH and temperature for OC and DCO solutions. In all cases, the extraction temperature was 20°C, 30°C and 40°C. The studied NaOH concentrations were 0.05, 0.075 and 0.1 M. The pH in OC solutions was 3, 5 and 7, and in DCO solutions, 4.7, 6.3 and 6.7. Water-washed and medium coarse soil fraction of arsenic, chromium and zinc contaminated soil was agitated for 15 min with the extraction solution. Results and discussion: In NaOH extractions, the temperature and (less strongly) NaOH concentration significantly affected As and Cr mobilisation, but only the latter affected Zn mobilisation. Both pH and temperature significantly (and similarly) influenced As and Cr mobilisation in OC extractions, while only the pH influenced Zn mobilisation. In contrast, the extraction temperature (but not pH) influenced As, Cr and Zn mobilisation in DCO extractions. Conclusions: For all extractants, mobilisation was most efficient at elevated temperature (40°C). None of the extractants reduced the soil's As content to below the Swedish EPA's guideline value. Use of DCO is not recommended because dithionite has a short lifetime and residual arsenic contents in DCO-extracted soil are relatively high. Instead, sequential extraction with NaOH followed by OC solutions (affording significant reductions in As, Cr and Zn levels in the soil with short extraction times) at 40°C is recommended

  • 141.
    Brännvall, Evelina
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Accelerate ageing of refuse-derived-fuel (RDF) fly ashes2010Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Ashes have properties that can be exploited in various applications, e.g. some ashes can be used in the construction of barriers in a landfill final top cover. A landfill top cover is a multilayer construction that protects the environment in several ways, for instance hindering gas emissions from the landfill body and water infiltration into the waste.Impervious natural materials like clay, synthetic materials like geomembranes or bentonite carpets, geosynthetic clay liners or combinations of such materials are commonly used in landfill top cover constructions. Since differential settlement may occur and the lifetimes of the synthetic materials are uncertain, it is advantageous to use thick mineral constructions. There is a great need for these materials, and substantial savings of resources can be made if alternative waste materials, like ashes, are used. Currently, ashes are either landfilled or used as construction materials. They are subject to weathering processes, including physical, chemical and mineralogical changes caused (inter alia) by fluctuations of temperature and humidity, atmospheric gases or acid rain. Ashes contain various potentially hazardous and non-hazardous chemical compounds. Therefore, precautions must be taken to avoid leaching of substances such as heavy metals into the surrounding environment. Mineral phases that are initially present and/or that form during the ageing are primarily responsible for the immobilization or leaching of diverse metals and salts. Newly formed mineral phases like clay minerals are of main interest, because of their very high cation exchange capacity, swelling and expansion properties.The conditions found in a landfill environment are likely to favour clay mineral formation. This thesis is based on studies on the effects of accelerated ageing on refuse-derived-fuel (RDF) fly ashes, in experiments under controlled laboratory conditions, intended to derive models to predict the stability of RDF fly ashes used in a landfill liner and the mineralogical changes that occur in them. A reduced factorial design was applied, followed by multivariate data analysis, to evaluate the effects of five factors - carbon dioxide (CO2) levels, temperature, relative air humidity (RH), time and the quality of added water - on mineral transformations within the ashes, and their acid neutralization capacity (ANC) and leaching behaviour.Minerals (ettringite and hydrocalumite) promoting the immobilization of hazardous compounds were found in both fresh ash and ash aged under atmospheric conditions, but these minerals disappeared upon carbonation. The main phases in ash at 20% and 100% CO2 were calcite, gypsum/anhydrite and vaterite. The abundance of gypsum and anhydrite was directly related to the temperature at which ashes were aged. The major mineral phases detected in ashes aged under 20% CO2, 65% RH and 30°C (corresponding to conditions generally found in a landfill cover) were calcite and gypsum/bassanite. The pH values of these ash specimens ranged from 7.2 to 7.6, indicating advanced carbonation. Ageing decreased pH values from 12.4 to 7.2, consequently affecting the leaching behaviour of most chemicals measured in the leachates. Levels of Ba, Ca, Cl, Cr, Cu, Pb, K and Na decreased over the study period while those of Mg, Zn and SO4 increased. No clay minerals were detected by XRD and SEM analysis in either fresh or aged ashes. However, geochemical modelling indicated that such minerals may precipitate. The modelling also indicated that clay minerals like saponite, vermiculite, chrysotile and hydrotalcite were likely to precipitate in most leachates from ash aged for 3, 10 and 22 months. Smectite, montmorillonite and illite may precipitate in leachates of ash aged for 31 months. The formation of smectite, montmorillonite and vermiculite would be advantageous due to their very high cation exchange capacities, which would favour the stabilization/immobilization of heavy metals in the mineral phases.

  • 142. Diener, Silvia
    et al.
    Andreas, Lale
    Herrmann, Inga
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Ecke, Holger
    Lagerkvist, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Accelerated carbonation of steel slags in a landfill cover construction2010In: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456, Vol. 30, no 1, p. 132-139Article in journal (Refereed)
    Abstract [en]

    Steel slags from high-alloyed tool steel production were used in a full scale cover construction of a municipal solid waste (MSW) landfill. In order to study the long-term stability of the steel slags within the final cover, a laboratory experiment was performed. The effect on the ageing process, due to i.e. carbonation, exerted by five different factors resembling both the material characteristics and the environmental conditions is investigated. Leaching behaviour, acid neutralization capacity and mineralogy (evaluated by means of X-ray diffraction, XRD, and thermogravimetry/differential thermal analysis, TG/DTA) are tested after different periods of ageing under different conditions.Samples aged for 3 and 10 months were evaluated in this paper. Multivariate data analysis was used for data evaluation. The results indicate that among the investigated factors, ageing time and carbon dioxide content of the atmosphere were able to exert the most relevant effect. However, further investigations are required in order to clarify the role of the temperature.

  • 143.
    Klausing, Benjamin
    et al.
    TU Hamburg-Harburg.
    Andreas, Lale
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Bilitewski, Bernd
    TU Dresden.
    Auswertung zweier reststoffbasierter Deponieabdeckungen2010Conference paper (Other academic)
    Abstract [en]

    Large amounts of material will be needed to install covers on closed landfill constructions due to the application of EU landfill directive 1999/31/EC. Approximately 1 million t of ashes are produced in Sweden each year. The interest in substituting conventional construction materials for landfill covers by alternative materials increases by the possibility to implement advantages, such as saving natural resources and economic benefits, using SCM. But to use SCM advantageous for the intended purpose, additional problems compared to the use of conventional materials have to be solved, such as availability, storing, preparation, planning and the construction process itself. Thorough investigations and experiments to characterize the used materials are a necessity. At Tveta Landfill in Södertälje field investigations are performed concerning different cover construction designs. During an excavation in 2007 samples from the different layers of the cover of two test fields were collected. In this study the development of the cover constructions is investigated focusing the mechanical and chemical stability of the cover constructions. During the investigations the bulk density, WHC and total composition of the material were analyzed and a diffusion test was performed. No negative development of the mechanical properties of the material due to ageing processes could be determined. The results of the analyses show that the construction process itself influences the future mechanical and chemical conditions of the cover construction. For example, the delayed covering of the protection layer of area 1 by the vegetation layer resulted in displaced concentrations for most considered components within the solid matter.The comparison of solid matter content and leaching behaviour before installation and after excavation after two and four years, respectively, indicate a trend to decreasing concentrations for most of the concerned components. The trend is only weak due to the short time the material was in place and because the amount of water that percolated through the layers was reported to be small. For some components enrichment especially in the protection layer of area 4 was determined. It could be shown that this enrichment is caused by the superimposed vegetation layer material, which contains high concentration levels for some elements. The transport path of these components leading to a contamination of the other layers by leaching could also be disclosed. The leaching behaviour of the fly ash used in area 4 was studied in a diffusion test using leachate from the protection layer as a way to understand the influence of different layers on each other. Moreover, the comparison of the results from this test with another diffusion test using distilled water reveals different behaviour depending on the used leachant. The diffusion occurs in the initial phase of the experiment for the concerned diffusion controlled components influenced by the leachate of the protection layer. A difference in the leached amounts could also be noticed. The stabilization of the mineral liner due to the formation of clay minerals could not be proved analytically, but the precursors reported to be necessary for this process could be determined.Leaching was found to have the main impact on the stabilization of the cover construction, causing the reduction of component concentrations and the approach to an equilibrium state between the cover and its environment. It was shown that the influence of leaching emissions on the environment is controllable. A risk for the environment was determined by the contaminated vegetation layer of area 4, hence uncontrolled emissions of components into the environment by plants and animals may occur.As a result of this study it is shown that the implementation of SCM is possible. Whether constructing with SCM is successful or not strongly depends on anticipatory planning and the design, the knowledge of the materials properties, their development over time and their interactions.

  • 144. Diener, Silvia
    et al.
    Andreas, Lale
    Brännvall, Evelina
    Lagerkvist, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Evaluation and discussion of steel slag mineralogy after ageing under laboratory and field conditions2010In: The 6th Intercontinental Landfill research Symposium, 2010, p. 107-109Conference paper (Other academic)
  • 145. Dahlén, Lisa
    et al.
    Lagerkvist, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Evaluation of recycling programmes in household waste collection systems2010In: Waste Management & Research, ISSN 0734-242X, E-ISSN 1096-3669, Vol. 28, no 7, p. 577-586Article in journal (Refereed)
    Abstract [en]

    A case study and a literature review have been carried out to address the two questions: how can waste flow data from collection systems be interpreted and compared? and which factors are decisive in the results of recycling programmes in household waste collection systems? The aim is to contribute to the understanding of how recycling programmes affect the quantity of waste and sorting activities. It is shown how the results from various waste sorting systems can be interpreted and made comparable. A set of waste flow indicators is proposed, which together with generic system descriptions can facilitate comparisons of different collections systems. The evaluation of collection systems depends on the system boundaries and will always be site-specific to some degree. Various factors are relevant, e.g. environmental objectives, technical function, operating costs, types of recyclable materials collected separately, property-close collection or drop-off systems, economic incentives, information strategies, residential structure, social codes, etc. Kerbside collection of recyclables and weight-based billing led to increased waste sorting activities in the case study. Forty-three decisive factors are listed and discussed.

  • 146.
    Lundmark, Carina
    et al.
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Social Sciences.
    Dahlén, Lisa
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Fokusgrupper för förbättrat samarbetsklimat mellan landstingets politiker och tjänstemän: en pilotstudie i Västernorrlands, Västerbottens och Norrbottens läns landsting2010Report (Other academic)
    Abstract [sv]

    Under hösten 2009 genomfördes en pilotstudie, där tjänstemän och förtroendevalda från Norrbottens och Västerbottens läns landsting samt Landstinget Västernorrland fick diskutera rollfördelning och samarbetsklimat i fokusgrupper, under ledning av två forskare från Luleå tekniska universitet. Syftet var att inventera deltagarnas erfarenheter och bidra till bättre förståelse för respektive parts arbetssituation och problembild. I rapporten redovisas de olika upplevelser och tolkningar som framkommit under diskussionerna, med särskild betoning på de förslag som deltagarna själva lyft fram som möjliga strategier att göra rollerna tydligare och förbättra samarbetsklimatet. Fokusgruppsdeltagarna var överens om att det behövs fler tillfällen att diskutera rollerna. Förståelsen för rollerna behöver fördjupas i en ständigt pågående process. Det är viktigt för både politiker och tjänstemän att förstå sin egen roll och att ha respekt för varandras roller. Det behövs också en medvetenhet om det gränsland som alltid kommer att finnas, där politik och förvaltning överlappar. Studien visar att heltids- och fritidspolitiker har helt olika förutsättningar att arbeta politiskt. Heltidspolitiker är med och sätter dagordningen, har täta kontakter med tjänstemännen och får god inblick i de ärenden som är på väg upp till beslut. Fritidspolitiker, särskilt de som enbart sitter i fullmäktige, kan uppleva beslutsförslagen som både svåra att förstå och svåra att påverka. Fokusgruppsdiskussionerna visade att fritidpolitiker i allmänhet och oppositionen i synnerhet behöver bättre förutsättningar för att kunna arbeta politiskt på ett meningsfullt sätt, till exempel föreslogs att överväga organisationsförändringar (Oppositionen med i beredningar? Tjänstemannatid reserverad för oppositionen? Politiska sekreterare?). Förbättrad måluppföljning lyftes fram som en förutsättning för att politiker ska kunna arbeta med mål på ett meningsfullt sätt. De förtroendevalda önskade också mer nyanserade beslutsunderlag samt tydligt medborgarperspektiv i beslutsunderlagens konsekvensanalyser. Tjänstemännen önskade en större politisk tydlighet och målinriktning hos de förtroendevalda. Fokusgruppsmetoden har fungerat bra, både för att inventera erfarenheter av relationen och för att förbättra deltagarnas förståelse för den andra gruppens situation.

  • 147. Brännvall, Evelina
    et al.
    Andreas, Lale
    Diener, Silvia
    Tham, Gustav
    Telge AB.
    Sjöblom, Rolf
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Lagerkvist, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Formation of secondary mineral phases during the ageing of RDF fly ashes2010In: The 6th Intercontinental Landfill Research Symposium, 2010, p. 110-112Conference paper (Other academic)
  • 148.
    Diener, Silvia
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Brännvall, Evelina
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Andreas, Lale
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Leaching properties of steel slags after ageing under laboratory and field conditions2010In: Third International Conference on Accelerated Carbonation for Environmental and Materials Engineering: ACEME10 : November 29 - December 1, 2010, Åbo Akademi University, Åbo/Turku, Finland : proceedings / [ed] Ron Zevenhoven., Åbo: Åbo Akademi University Press, 2010Conference paper (Refereed)
  • 149. Dahlén, Lisa
    et al.
    Lagerkvist, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Pay as you throw: strengths and weaknesses of weight-based billing in household waste collection systems in Sweden2010In: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456, Vol. 30, no 1, p. 23-31Article in journal (Refereed)
    Abstract [en]

    Householders' response to weight-based billing for the collection of household waste was investigated with the aim of providing decision support for waste management policies. Three questions were addressed: How much and what kind of information on weight-based billing is discernible in generic Swedish waste collection statistics? Why do local authorities implement weight-based billing, and how do they perceive the results? and, Which strengths and weaknesses of weight-based billing have been observed on the local level? The study showed that municipalities with pay-by-weight schemes collected 20% less household waste per capita than other municipalities. Surprisingly, no part of this difference could be explained by higher recycling rates. Nevertheless, the majority of waste management professionals were convinced that recycling had increased as a result of the billing system. A number of contradicting strengths and weaknesses of weight-based billing were revealed.

  • 150.
    Herrmann, Inga
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Diener, Silvia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Andreas, Lale
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Lind, Lotta
    Steel slag used in landfill cover liners: laboratory and field tests2010In: Waste Management & Research, ISSN 0734-242X, E-ISSN 1096-3669, Vol. 28, no 12, p. 1114-1121Article in journal (Refereed)
    Abstract [en]

    Stricter rules for landfilling within the EU have led to the closure of many landfills and a need for large amounts of cover liner materials. Therefore, the potential utilization of mixtures of electric arc furnace slag (EAFS) and ladle slag (LS), which are currently deposited in landfills, as a material for use as landfill liner was investigated. Laboratory analyses showed the mixtures to have similar compression strength to that of high-strength concrete and low hydraulic conductivity (<10-11 m s-1 in some cases). However, both their hydraulic conductivity and compaction properties were strongly affected by the time between adding water to the mixtures and compacting them (tests showed that a delay of 24 h can lead to an increase in hydraulic conductivity, so it should be compacted as soon as possible after mixing the material with water). In addition, the performance of a cover liner constructed using EAFS and LS was studied in a 2-year field trial on a landfill for municipal solid waste, in which the average amount of leachate collected from ten lysimeters was only 27 L m-2 year-1, easily meeting Swedish criteria for the permeability of covers on non-hazardous waste landfills (≤50 L m-2 year-1). Thus, the material seems to have promising potential for use in barrier constructions.

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