Groundwater is an important source of drinking water where advanced knowledge in the area is of great importance in order to ensure the drinking water quality for future generations. Groundwater is chemically complex because it is formed from a large variety of water sources where the water comes from and passes through different geological and hydrological environments. Environmental forensics is an important area in environmental studies where a wide variety of analytical techniques are integrated to be able to trace and identify sources of pollution. In the Gäddvik project, environmental forensics is applied as a method for tracking pollution in naturally occurring waters. Concentrations of selected elements, oxygen- and hydrogenisotopes and cerium-anomalies have been used to show chemical differences between different water sources in groundwater reservoirs in the Gäddvik area. A sub-study at Kvarnträsket (a lake located in the Gäddvik area) has been carried out to track surface water intrusion in nearby groundwater used for drinking water. Different types of graphs and charts have been created from data on the area, where these have been used to give a simplified visualization of different geochemical trends for selected elements/isotopes. Quality differences between two nearby groundwater reservoirs have been studied and discovered, where one is Luleå’s main groundwater reservoir and the other is a backup groundwater reservoir. Surface water from the Luleå River has been detected in the main groundwater reservoir to a greater extent than in the backup groundwater reservoir. This may be since the main reservoir is under higher exposure and uses river water for artificial infiltration to the groundwater. Oxygen- and hydrogenisotopes have been shown to be useful for tracking and locating surface water infiltration in groundwater intended for drinking water. / Grundvatten är en viktig källa för dricksvatten där en utvecklad kunskap inom området är av stor betydelse för att kunna säkerställa dricksvattenkvalitén för framtida generationer. Grundvatten är kemiskt komplext eftersom det bildas från en stor variation av vattenkällor där vattnet kommer från och passerar genom olika geologiska och hydrologiska miljöer. Environmental forensics är ett viktigt område inom miljöstudier där man integrerar en bred variation av analytiska tekniker för att kunna spåra och identifiera föroreningskällor. I Gäddviksprojektet tillämpas environmental forensics som metodik för spårning av föroreningar i naturligt förekommande vatten. Koncentrationer av valda element, syre- och väteisotoper samt cerium-anomalier har använts för att visa kemiska skillnader mellan olika vattenkällor vid vattentäkter i Gäddviksområdet. En delstudie vid Kvarnträsket (en sjö belägen i Gäddviksområdet) har genomförts för att spåra ytvattenintrång i närliggande grundvatten som används för dricksvatten. Olika typer av grafer och diagram har skapats från data över området, där dessa har använts för att förenklat visualisera olika geokemiska trender för valda element/isotoper. Kvalitetsskillnader mellan två närliggande vattentäkter har studerats och upptäckts där ena täkten är Luleås huvudvattentäkt och den andra är en reservvattentäkt. Ytvatten från Luleälven har upptäckts i huvudvattentäkten i större utsträckning än reservvattentäkten. En potentiell orsak till detta är att huvudvattentäkten är under högre belastning och använder älvvatten för konstgjord infiltration till grundvattnet. Syre- och väteisotoper har visats användbara för spårning och lokalisering av ytvattenintrång i grundvatten avsedda för dricksvatten.

Design is described as the main factor influencing a product's sustainability, and with industrial growth, global interest in sustainability issues has also increased. Furthermore, the design process is an important part when companies are to reduce climate impact of their products, and that the demand for more environmentally friendly products is increasing. Due to both an expanded legal framework and increased consumer demand for green products, the concept of sustainable product development has been increasingly established and received greater attention. A method to determine the environmental impact of a product during its life cycle is to perform a life cycle assessment (LCA). However, conducting a LCA requires large amounts of information, information that can often be unreliable and difficult to obtain. For this reason, together with the fact that a LCA is both time-consuming and costly to carry out, there is reason to explore the possibilities for a simplified life cycle assessment (SLCA).  The aim of this thesis is to investigate how a SLCA-tool could be created to support decision making in the product development process (PDP). Furthermore, the thesis intends to investigate how a SLCA-tool can be successfully integrated and used, and what role a SLCA-tool have in the PDP process. This tool creation will therefore contribute to more knowledge in the implementation of SLCA in manufacturing companies. A qualitative approach was used to address the aim of the paper. The methodology used was five-folded and included 1) preliminary study, 2) specification, 3) creation of tool, 4) verification of tool and 5) implementation. The creation of the tool was based on the conditions of a multinational company within the manufacturing sector. The results indicate that the user-friendliness of a SLCA-tool should be prioritized over the precision, on the basis that the tool should be used by designers with a mandate to make decisions about the design of a product. A SLCA-tool should therefore mainly focus on the raw material extraction and use phase, as these are the life cycle phases that generally have the highest climate impact, but it should also consider the other life cycle phases of a product. This reduces the number of choices the user has to make. To further help users make sustainability-related decisions in the PDP, a SLCA-tool should help them compare the environmental impact of different design options. Despite the gross simplifications, the evaluation of the developed SLCA-tool shows that the distribution of climate impact between the life cycle phases can largely be the same in a SLCA-tool as in a full scale LCA. By setting sustainability objectives early in the PDP and engaging an early integration of a SLCA-tool, even if the information about the product is initially limited, sustainability can be concretized and become a design parameter like time to market and cost. Through the early integration into the PDP, a SLCA-tool can also be used in a business context in Product Portfolio Management to ultimately develop a sustainable technology portfolio that meets customer needs.   The creation of a SLCA-tool, based on company-specific conditions, gives hope for successful implementation and use, but the tool should also be evaluated after a period of implementation to determine its final effect on decision-making in the PDP. What is also important to consider is that the tool developed in this thesis only takes into account the climate impact, and thus a system perspective should be applied by complementing other ecodesign tools to avoid sub-optimization in decision-making. Furthermore, it should also be kept in mind that the main purpose of a SLCA is to map a product's climate impact and understand how resources can be allocated to reduce the climate impact of a product.  If there is an awareness of these conditions, a SLCA-tool can both reduce cost and time, compared to a full scale LCA, to support decision-making in the PDP from a climate perspective.

In this thesis a semi-automatic method is developed to analyze morphometric features and landscape elements based on Self Organizing Map (SOM) as a unsupervised Artificial Neural Network algorithm. Analysis and parameterization of topography into simple and homogenous land elements (landform) can play an important role as basic information in planning processes and environmental modeling. Landforms and land cover are the main components of landscapes. Landscapes are dynamic systems that involve interrelation between physical characteristics (such as landform, soil) and anthropogenic processes (such as land use). In morphometry (as general term of geomorphometry) - the qualitative and quantitative measurement of topography - morphometric parameters are calculated such as profile curvature and longitudinal curvature. They are then used in morphometric analysis to identify morphometric features like plane, channel, ridge, peak or pit. In February 2000 the Shuttle Radar Topography Mission (SRTM), collected data over 80% of the Earth's land surface, to derive a consistent digital elevation model (DEM) for allland areas between 60 degrees N and 56 degrees S latitude. This DEM with about 90 m grid spacing was used to generate morphometric parameters of first order (slope) and second order (minimum curvature, maximum curvatures and cross-sectional curvature) by fitting a bivariate quadratic surface. These surface curvatures are strongly related to landform features and geomorphological processes. The thesis starts with an overall introduction and literature review. Then two methods for morphometric analysis are compared: morphometric parameterization and feature extraction proposed by Wood (1996a), calculated with Geographic Information Systems (GIS) software and our method implemented with Self Organizing Map (SOM) as an nsupervised artificial neural networks paradigm. Finally in our method for landscape element analysis morphometric parameters and remotely sensed spectral data are combined. The emphasis is on morphologically homogeneous landscape elements characterized by similar slope and curvature conditions. SOM is used to reduce large multidimensional data sets to one output layer consisting of 20 map units. These map units are interpreted in terms of morphometric features, slope and land cover to identify and characterize landscape elements or geoecological units Both studies have demonstrated valuable methods for extraction of land information that can be used in geomorphologic applications and geoecosystem modeling. These methods allow important savings in field work and can be used as alternative to labor intensive manual methods. But results may depend on scale and quality of the DEM and the topographic situation; caution should be used in interpretation. Evaluation of these methods in other areas with different morphometric conditions and with multi-scale DEM remains to be done. / QC 20101104

Lidingö har sedan 2010 erbjudit sina invånare att bli abonnenter av tjänsten för matavfallsinsamling. Trots årliga kampanjer har de dock inte samma anslutningsgrad som kommuner som har ett taxerings - och insamlingssystem som fungerar på liknande sätt. Syftet med detta arbete är därför att svara på; Varför sorterar inte småhus ut matavfall i Lidingö stad trots att det finns förutsättningar för det? Genom litteraturstudier och utskickad enkät till boende på Lidingö har anledningar till varför majoriteten av småhus-hushållen inte är abonnenter tagits fram samt vilka åtgärder som Lidingö stad kan bistå med för att få fler av dessa att bli abonnenter. Det som identifierades som anledningar till att Lidingöbor inte sorterar var främst att de var oroliga för lukt, de hade för lite matavfall och de saknade information. Kampanjer som ansågs fungera väl genom resultat från litteraturstudier i beteendeförändring och jämförelse med andra kommuner var att använda informatörer eller dörrknackare samt att involvera boende i funktionen och driften av systemet. De slutgiltiga åtgärdsförslagen till Lidingö var att synliggöra information bättre och på ett sätt som får de boende att känna sig personligt engagerade till att sortera samt att minska trösklarna i systemet. / Lidingö has since 2010 offered residents to become subscribers of the food waste collection service. Despite annual campaigns they do not have the same connection rates as municipalities that have a taxation and collection system that works similarly. The purpose of this work is therefore to answer; Why does not single-family houses sort out food waste in Lidingö stad despite they have the conditions to do it? Through literature studies and a questionnaire sent to residents in Lidingö, reasons have been identified as for why the majority of small-family households are not subscribers, and what means Lidingö stad can use to get more subscribers. What was identified as a reason why citizens of Lidingö did not sort was primarily that they were worried about smell, they had too little food waste and they lacked information. Recommended campaigns that were identified through results from literature studies in behavioural change and comparison with other municipalities are; use informers or door-stepping and involve residents in the functioning and operation of the system. The final action proposals for Lidingö stad is to make information better visible and in a way that makes the residents feel personally involved in sorting and reducing the thresholds in the system.

Sweden is striving towards a carbon neutral transportation sector by2030 which includes reductions from CO2 emissions by 70%. This thesis focusses especially on the decarbonization of road freight transportation. Even though electrification of vehicles is seen as one of the available options to reach this goal, present battery technology does not meet requirementsof energy density and cost. The electrification of roads with electrified road systems (ERS) enables vehicles to charge electrical energy while in motion and has the potential toreduce weight and costs of on-board batteries for electric vehicles and avoids range anxiety of vehicle operators. Within this Master’s thesis, available ERSs are assessed and it is shown which of the available systems performs best in selected categories. Furthermore, alterantive options for large CO2 emission reductions in the roadtransportation sector are evaluated and it is shown that ERSs constitute the most promising alternative. Results of this dissertation are based on a qualitative research approachand limited to data availability.

Climate change poses a critical threat to future development and is a reality that affects our society, our way of thinking and acting. The international body has taken common position against climate change in the expression of, inter alia, the Paris Agreement on climate change and the Sustainable Development Agenda. Likewise, the Swedish Government’s is aiming for climate neutrality by 2045. This in parallel to the fact that public awareness and knowledge of sustainability grow, the pressure to deliver environmentally friendly, ethical, and economically profitable products increases. The increased pressure on organizations within both public and private sectors leave no opportunity to escape as everyone is required to assist against the common goals. For organizational survival, it is thus important to find new ways of tying societal improvement with business, calling for new forms of knowledge and competence. Infrastructure investments play a fundamental function to achieve sustainable development and empower communities as they enhance economic growth, reduces inequality and improve the quality of life. Simultaneously, the climate impact from construction, operation, and maintenance of infrastructure is significant. Knowledge, practical advice and guidance to cope with increased requirements for reducing greenhouse gas emissions are available. In addition, awareness of the need for systematic climate work has increased in line with the introduction of new requirements and guidelines. Nevertheless, the climate perspective is still not a natural part of the mindset and process and the level of achievement of climate-related goals can be considered too low This study aims at investigating how climate mitigation practices can be updated to truly facilitate and enable integration of a climate perspective into the work of designers and contactors working in multidisciplinary infrastructure projects. The study was conducted in the context of a large infrastructure project concerning the construction and expansion of a significant railway segment in Sweden. Among other things, the project include construction of a tunnel in a highly demanding environment involving major climate challenges and a number of aggravating factors. By studying practices, collaborations, and use of external expertise in parallel with how projects proceed and actors operate the study contributes with deeper understanding of existing challenges and key factors for improved integration. The study's analyzed results indicate a number of contributing factors that complicate integration of a climate perspective, among others lack of ownership and risk-taking of the process, lack of knowledge, time and feedback, structural barriers, skepticism, inadequate communication, etc. The conclusion provides four recommendations for further addressing the matter: new contract and procurement models, development of educational packages, review and develop the toolbox of designers and engineers, and evaluate existing practices. / Klimatförändringar utgör ett centralt hot mot vår framtida utveckling och är en realitet som påverkar vårt samhälle, sätt att tänka och agera. Världssamfundet har tagit gemensam ställning mot klimatförändringar i uttryck av bland annat Parisavtalet. Likaså har den svenska regeringen stiftat mål om klimatneutralitet år 2045. Detta parallellt med att allmänhetens ökade medvetenhet och kunskap om hållbarhet, ökar pressen att leverera miljövänliga, etiska och ekonomiskt lönsamma produkter. Den ökade pressen på organisationer inom både den offentliga och privata sektorn lämnar inget utrymme att ducka, eftersom alla är skyldiga att sträva mot de gemensamma målen. För organisatorisk överlevnad är det således viktigt att hitta nya sätt att kombinera samhällsnytta med företagsamhet vilket ökar efterfrågan av kompetens och kunskap inom området. Att investera i infrastruktur är en grundläggande funktion för att främja hållbar utveckling och stärka samhällen, eftersom det bidrar till ökat tillväxt, jämställdhet och förbättrad livskvalité. Samtidigt är klimatpåverkan från byggnation, drift och underhåll av infrastruktur betydande. Kunskap, praktiska råd och vägledning för hantering av ökade klimatkrav för minskade utsläpp av växthusgaser finns tillgängliga. Därtill har medvetenheten om behovet av systematiskt klimatarbete ökat i linje med att nya krav och riktlinjer introducerats. Trots detta, är klimatperspektivet fortsatt inte en naturlig del av tanke- och arbetsprocessen och nivån på uppnående av klimatrelaterade mål kan anses vara för låg.  Denna studie syftar till att undersöka hur tillämpade arbetssätt kan uppdateras för att underlätta och möjliggöra integration av ett klimatperspektiv hos projektörer och entreprenörer som arbetar i multidisciplinära infrastrukturprojekt. Studien genomfördes i samband med ett stort infrastrukturprojekt som avser byggnation och utbyggnad av ett i Sverige betydande segment järnväg. Bland annat involverar projektet byggnation av en tunnel i en krävande miljö vilket medför stora klimatutmaningar och ett antal försvårande faktorer. Genom att studera tillämpade arbetssätt, samverkan och användning av extern expertis parallellt med hur projekt fortgår och aktörer arbetar bidrar studien med djupare förståelse av befintliga utmaningar och nyckelfaktorer för förbättrad integrering. Studien ger rekommendationer för vidare behandling av frågan. Studiens analyserade resultat indikerar ett antal bidragande faktorer som försvårar integreringen av klimatfrågan, bland annat bristande ägandeskap och riskupptagande i processen, bristande kunskap, tid och återkoppling, strukturella hinder, skepsis och bristfällig kommunikation. Studiens slutsats ger fyra rekommendationer för vidare arbete: nya kontrakts- och upphandlingsmodeller, utveckling av utbildningspaket, granskning och utveckling av verktygslådan till konstruktörer och ingenjörer samt utvärdering av befintliga arbetsmetoder.

Steel slags are by-products of the steelmaking process. To avoid unnecessary disposal, e.g. into landfill, their chemical and physical properties should be exploited to support alternative uses. Steel slags can be recycled within the steel plant or used as construction material in roads, hydraulic engineering and different types of barriers, including landfill covers. A landfill cover consists of several layers, including a liner with low water and gas permeability in order to reduce methane and leachate emissions. Several studies have demonstrated that steel slags have good potential to fulfil such an application. However, there are questions regarding the stability of the slag minerals over long periods of time. A landfill cover must function well for many decades and centuries. In order to predict the long-term stability of steel slags as a landfill liner, laboratory experiments have been performed to study the effects of accelerated ageing of steel slag under controlled conditions. The factors investigated in the storage atmosphere were carbon dioxide content, relative humidity and temperature. The influence of leachate contact and ageing time were also assessed.This thesis reports the study of electric arc furnace slags and ladle slag from the production of high-alloyed tool steel after accelerated ageing for periods of three months and ten months. Mineralogy and leaching were studied using two different leaching tests, thermal analysis, acid-neutralization capacity assays and X-ray diffraction. For the ageing periods considered, the exposure of the slags to an atmosphere enriched with carbon dioxide had the greatest impact on leaching. In general, calcium, aluminium, sulphur and sodium leached from the slag matrix to the greatest extent while other metals such as chromium, nickel, lead and zinc were found at very low levels in the leachate. The leaching of calcium and aluminium reduced with increasing carbon dioxide level. Thermal analysis revealed the decomposition of carbonates. Weight and enthalpy changes were evaluated between 100 and 1000 °C. The buffer capacity of the steel slags, represented by the acid neutralization capacity (ANC 4.5) was not reduced after 10 months of ageing. However, the division of the titration into two steps revealed a shift of buffering zones for more highly aged samples, probably due to the formation of carbonates. The mineralogy of the investigated steel slags was complex with a large variety of mineral phases, principally calcium silicates, monticellite, periclase and a spinel phase. Other possible phases were gehlenite, merwinite, akermanite and iron. The existence of different solid solution is likely among the slag phases and can cause shifting of peaks in the X-ray diffractogram. Also, calcite was identified. Short-term carbonation has not shown significant impact on mineralogy despite of calcite formation. The results of the study contribute to a better understanding of the chemical and mineral stability of electric arc furnace slag and ladle slag in the environment of a landfill liner. The consequences of slag ageing include reduced leaching rates for certain elements. To predict the long-term behaviour of aged slag, the results of this study should be combined with data from two other sources - an ongoing ageing experiment that includes mechanical tests and a full scale field test at the Hagfors landfill. Additional analytical methods that can better characterise the mineralogy, for example scanning electron microscopy (SEM) and energydispersive X-ray spectroscopy (EDX), should also be applied to better quantify the mineralogical phases and to determine which trace elements are most abundant in specific minerals. / Stålslagg är en restprodukt som kommer från ståltillverkningen. Den har kemiska och fysikaliska egenskaper som bör utnyttjas och som gör den lämplig för återanvändning, samtidigt som onödig deponering kan undvikas. Stålslagg kan återanvändas inom ståltillverkningen eller så kan den användas som konstruktionsmaterial i väg- och vattenbyggnadskonstruktioner eller i olika typer av barriärkonstruktioner som till exempel deponisluttäckningar. En deponisluttäckning består av flera skikt där tätskiktet ska ha en låg vatten- och gaspermeabilitet för att minska metan- och lakvattenutsläpp. Flera studier visar att stålslagg uppfyller dessa egenskaper och har potential att kunna användas i deponitäckning. Men det finns fortfarande oklarheter angående slaggmineralernas stabilitet över en längre tid. En deponitäcknings funktion förväntas vara stabil i många tiotals eller hundratals år. För att kunna förutsäga det långsiktiga beteendet för stålslagg i ett tätskikt genomfördes ett laboratorieexperiment vars syfte var att studera effekterna av accelererad åldring under kontrollerade förhållanden. De faktorer som studerades var koldioxidhalten, relativa luftfuktigheten, temperaturen, kontakten med lakvatten samt åldringstiden. I denna avhandling presenteras undersökningen av ljusbågsugnsslagg och skänkslagg, från framställning av höglegerat verktygsstål, efter tre respektive tio månaders accelererad åldring. Mineralogin och lakningsegenskaperna studerades genom två typer av laktester, termiska analyser, analys av syraneutraliserande kapacitet samt röntgendiffraktion. För de studerade åldringstiderna var det exponeringen av stålslaggen för en koldioxidrik atmosfär som hade den största inverkan på lakningsegenskaperna. Kalcium, aluminium, svavel och natrium var de ämnen som uppvisade den högsta utlakningen från slaggen medan metaller som krom, nickel, bly och zink endast fanns i väldigt låga koncentrationer i lakvattnet. Utlakningen av kalcium och aluminium minskade med en ökande halt av koldioxid. Termiska analyser visade på en nedbrytning av karbonater. Vikt- och entalpiförändringar mellan 100 och 1000°C utvärderades. Stålslaggens buffertkapacitet, representerad av den syraneutraliserande kapaciteten (ANC pH 4,5), reducerades inte efter tio månaders åldrande. Däremot visade uppdelningen av titreringen i två steg på en förskjutning av buffertområdena för de prover som åldrats tio månader, förmodligen på grund av karbonatbildning. Mineralogin för de undersökta stålslaggerna var komplex med en stor variation av mineralfaser, främst kalciumsilikater, monticellit, periklas och en spinellfas. Andra möjliga mineralfaser var gehlenit, merwinit, åkermanit och järn. Förekomsten av olika fastfaslösningar i stålslaggsmineralerna är sannolik vilket kan orsaka förskjutningar av topparna i diffraktogrammen. Kalcit identifierades också. Karbonatisering under en kort tid visade sig inte ha någon signifikant inverkan på mineralogin, förutom en viss kalcitbildning. Resultaten från studien bidrar till en bättre förståelse av stabiliteten för ljusbågsugns- och skänkslagg i den miljö som finns i ett tätskikt. Åldringen av slaggen resulterade i en reducerad utlakning av vissa element. För att kunna förutsäga det långsiktiga beteendet för åldrad slagg bör resultaten från den här studien kombineras med data från ett pågående åldringsförsök som inkluderar mekaniska tester samt ett fullskaligt fältförsök på Hagfors deponi. Analysmetoder som mer detaljerat kan karaktärisera mineralogin, till exempel svepelektronmikroskopi (SEM) och energidispersiv röntgenspektroskopi (EDX), bör också användas för att bättre kunna kvantifiera mineralfaserna och bestämma vilka spårelement som är vanligast i specifika mineraler.

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. / Askor har egenskaper som kan användas, en del askor kan t ex användas vid konstruktion av tätskikt i en deponisluttäckning. En deponisluttäckning är en flerskiktskonstruktion som skyddar miljön från t.ex. växthusgaser från deponin och hindrar vatteninträngning till avfall. Naturliga täta material som lera, syntetiska som geomembraner eller bentonitmattor eller en kombination av dessa är vanligt förekommande i sluttäckningskonstruktioner på deponier. Eftersom differentialsättningar kan uppkomma och de syntetiska materialens livslängd är osäker, är det en fördel om tjocka mineraliska konstruktioner kan användas. För dessa är materialbehovet stort och det är en stor resursbesparing om alternativa material, som aska, kan användas.Aska utsätts för åldringsprocesser både när den deponeras eller användas som byggmaterial. Materialet genomgår fysiska, kemiska och mineralogiska förändringar orsakade av t.ex. variationer av temperatur och luftfuktighet, atmosfäriska gaser eller surt regn. Aska innehåller olika farliga och ofarliga kemiska föreningar. Därför måste försiktighetsåtgärder vidtas för att undvika läckage av tungmetaller i miljön. Befintliga och nybildade mineralfaser är främst ansvariga för immobilisering eller utlakning av olika metaller och salter. Nybildade mineralfaser som lermineraler är av stort intresse på grund av deras mycket höga katjonutbyteskapacitet, svällnings- och expansionsegenskaper. Förhållandena som råder i en deponisluttäckning förväntas gynna lermineralbildning.Denna avhandling är resultatet av studier av effekten av accelererad åldring på flygaska från energiutvinning. För att förutsäga stabiliteten i flygaska som används i ett deponitätskikt har laboratorieexperiment utförts för att studera effekterna av accelererad åldring under kontrollerade förhållanden. Ett reducerat faktorförsök har gjorts för att utvärdera påverkan av fem faktorer: koldioxid (CO2), temperatur, relativ luftfuktighet (RH), tid och kvalitet på tillsatt vatten. Inflytandet av dessa faktorer på mineralomvandlingen i askan, askans syraneutraliserande förmåga (ANC) och urlakningsbeteendet har analyserats och utvärderats med hjälp av bl a multivariat dataanalys. Mineraler (ettringit och hydrocalumit) som främjar fixeringen av farliga ämnen finns i både färsk aska och prover som åldrats under atmosfäriska förhållanden men försvann efter karbonatisering. Aska som åldrats under 20 % och 100 % CO2 hade kalcit, gips / anhydrit och vaterit som huvudmineraler. Förekomsten av gips och anhydrit var direkt relaterad till temperaturnivån som askan hade åldrats i. Aska som åldrades under 20 % CO2, 65 % RH, 30 °C temperatur (motsvarande förhållandena i en deponitäckning) hade kalcit och gips/bassanit som huvudmineraler. pH-värdena i proverna varierade från 7,2 till 7,6 vilket indikerar en långt fortskriden karbonatisering. Åldrandet sänkte pH-värdena från 12,4 till 7,2 och påverkar därmed urlakningsbeteendet för många lakvattenkomponenter. Barium, Ca, Cl, Cr, Cu, Pb, K och Na minskade under tiden, medan Mg, Zn och SO4 ökade jämfört med den färska askan. Inga lermineraler upptäcktes med hjälp av XRD och SEM i varken färsk eller åldrad aska. Geokemisk modellering visade dock möjligheten för dessa mineraler att bildas och fällas ut. Lermineraler som saponit, vermikulit, krysotil och hydrotalcit kunde enligt beräkningarna bildas i lakvatten från de flesta proverna som åldrades i 3, 10 och 22 månader. Smectit, montmorillonit och illit kan bildas i lakvatten från 31 månaders åldrad aska. Bildning av smectit, montmorillonit och vermikulit skulle var värdefull på grund av deras mycket höga katjonutbyteskapacitet, vilket gynnar stabilisering / immobilisering av tungmetaller i askan.

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.

Bottom ash has similar properties as crushed rocks and gravel, andcould replace some of the 40 million tonnesof virgin material used for road constructions each year.However, results presented in the literature indicate thatthe leaching of e.g. Cr, Cu, Mo, Pb and Zn can cause athreat to the sur rounding environment if the materialis used as it is. A common pre-treatment method is carbonation, whichwill reduce the pH and thereby decrease the leaching of several metals. This treatment is however not always enough, so alternative methods areneeded. One possibility could be to increase the number of sorption sites for the metals. The importance of iron oxides as sorption sits for metals isknown from both mineralogical studies of bottom ash as well as from theremediation of contaminated soil, where iron is used as an amendment.Zero valent iron (Fe 0) was therefore added prior to accelerated agingin order to increase the number of adsorption sites for metals and thereby improving the leaching quality. The performed leaching tests showed that theaddition of Fe 0 prior to accelerated aging improved the quality of the leachate compared with untreated bottom ash. There was also a significant de crease of Cu, Cr, Mo and Zn from bottom ash treated with Fe0 prior to accelerated aging com pared with bottom ash submitted to only accelerated aging. In order to make an environmental assessment of the bottom ash pretreated with Fe 0 prior to accelerated aginggeochemical modeling was performed using different pH and redox potentialsin order to simulate variations in the environment.The results in dicated that the leaching of Cr, Cr, Mo and Pb would not cause harm to the environment.Zn, however, was affected by changes in pH and leached in harmful aounts at pH values velow 6 and above 10.There are reasons to question the results from the geochemical modellingsince the results from pH-stat tests showedthat several elements leached at potentially harmful levelsat several of the tested pH. To fully evaluate the effect of addition of Fe0should the mineralogy of the pretreated bottom ash be evaluated further, in order to see what forms iron oxides are pre sent and if other metals are associated with them. However, in order to improve the quality of bottom ash,focus should be directed torwards what type of wastes that areincinerated and on the incineration process.