Managing anthropogenic emissions in urban areas is a major challenge in sustainable environmental development for cities, and future changes and increasing urbanisation may increase this challenge. Systems perspectives have become increasingly important in helping urban managers understand how different changes may alter future emissions and whether current management strategies can efficiently manage these emissions. This thesis provides some systems perspectives that have been lacking in previous studies on modelling and managing future anthropogenic emissions in urban areas. The city of Stockholm, Sweden, was selected as the study site and studies about nitrogen, phosphorus and carbon were chosen, given world-wide urban eutrophication and global concerns about climate change. A substance flow analysis (SFA) structured model, comprising a source model coupled with a watershed model in an SFA structure, was developed to investigate future nutrient loading scenarios under various urban changes in small urban lake catchments. The results demonstrated that climate change potentially posed a greater threat to future nutrient loads to a selected lake catchment in Stockholm than the other scenarios examined. Another SFA-based study on future phosphorus flows through the city of Stockholm indicated that the best management option may depend on the perspective applied when comparing future scenarios of phosphorus flows and that both upstream and downstream measures need to be considered in managing urban phosphorus flows. An evaluation approach for examining current management plans and low-carbon city initiatives using the Driving forces-Pressure-States-Impact-Response (DPSIR) framework, was formulated. With such an evaluation approach, investigation of how well selected plans cover different aspects of the DPSIR framework and whether root causes and systematic measures are highlighted is possible. The results revealed that the current low-carbon city initiative in Stockholm falls within pressure-based, driver-orientated plans and that technical, institutional and cognitional measures are generally well covered. / <p>QC 20160510</p>

In this study the opportunities to recycle the phosphorus contained in food handling were identified in four municipalities in the county of Östergötland. The aim was to map the flow and find out whether there were differences between municipalities with food processing industries generating large amounts of waste or phosphorus rich wastewater, or if there were differences between municipalities of different size. It was also investigated to what extent the agricultural demand of phosphorus could be covered by recycling of phosphorus from the food handling system. The result showed that between 27% and 73% of the phosphorus was found in the sludge from wastewater treatment, and that between 13% and 49% of the phosphorus was found in the centrally collected organic waste. This corresponded to 11% of the phosphorus demand on arable land in municipalities with food processing industries generating large amounts of waste or phosphorus rich wastewater, and 8% of the phosphorus demand on arable land in municipalities without such industries.

End products of society (e.g. sewage sludge and incineration ashes) can be used as indicators of the use of chemicals in consumer goods. Through upstream work the sources of substances released from goods may be identified before the emissions reach the end products. This thesis is a result of five studies, of which four were conducted using substance flow analyses (SFA) for silver (Ag), bismuth (Bi) and copper (Cu) reaching sewage sludge. The fifth is an SFA that explores the implications of the presence of As (from CCA-treated wood) in ashes. These studies helped fulfil the specific and overall aims of the thesis; to contribute to the general knowledge on diffuse emissions reflected in end products, by examining emissions of some heavy metals from various societal goods and the implications for end products, in this case sewage sludge and, to some extent, ashes. The results from the studies, of which four had Stockholm as a study object, show the urban flows and accumulated amounts (stocks) of the heavy metals. The largest sources of the metals Ag, Bi and Cu in sewage sludge were identified to be textiles (Ag), cosmetics (Bi) and brake linings (Cu). For As (in CCA-treated wood) and Cu updated SFAs were performed and compared with earlier studies in order to follow the development and changes in flows over time. The current use of the heavy metals studied can also be seen as a loss of resources, and as the metals should ideally be recovered as a part of a circular economy, urban and landfill mining as well as recycling are alternatives that need further exploring. The legislation of chemicals in consumer goods was identified as an important step in handling corresponding diffuse emissions.

Life cycle analysis is an appropriate way to clear obscure facts about an element. Gallium is a critical element which is used in many technologies these days and therefore quantification of main global cycles of gallium, production, consumption and end of life products, also investigation about recycled gallium content and potential recycling possibilities are investigated in this paper. First a qualitative substance flow for gallium is designed similar to other metal cycles with regards to exclusive characteristics of gallium flows itself. USGS and World Mining Data are mainly used to get information about gallium production, main gallium consumptions and end of life products. Subsequently a quantitative model in STAN should unlock many uncertainties. Substance flow analysis and material flow analysis give a better understanding of unknown gallium flows with their uncertainties and meanwhile major applications, concentration of gallium in different products, waste flows, landfills and present recycling technologies are detailed. Consequently STAN model asserts that main gallium flows are primary gallium production and refined gallium production in production process, Integrated Circuit board fabrication, Light Emitting Diodes, Photovoltaic and recycled new scrap flow in manufacturing process. A significant amount of gallium is collected as stock in consumption process. Also current gallium recycling facilities are limited as recycling is not economically justified. Moreover main part of recycled gallium content is collected from new scrap which is formed through manufacturing process. Finally gallium consumption in Photovoltaic and Light Emitting Diodes industry increases rapidly and sustainability demand cost efficient methods for gallium recycling from solar cells, diodes and other end of life products.

Carbon (C) is an essential element for all life. However, modern livestock keeping and usage of carbon through burning of fossil fuels are resulting in increased concentrations of carbon dioxide and methane in the atmosphere, two important greenhouse gases (GHG).  Rising concentrations of  GHGs in the atmosphere  is one of the world’s most pressing issues  and  is evidently resulting in rising global temperatures. Nations are fighting to reach net zero emissions of carbon dioxide, and Sweden has set out to have net zero emissions by 2045. To reach this goal, system changes are needed over all sectors in Sweden. The aim of this study is therefore to provide a holistic picture of anthropogenic carbon flows, sources and sinks in Sweden to contribute to a better understanding of the functioning of the Swedish anthropogenic  carbon system. This is done by quantifying the most significant  anthropogenic  carbon sources, flows, and sinks, and visualise them in substance flow charts. The results from this study will thus provide insight into the functioning of the Swedish anthropogenic carbon system.  Through the practical usage of Substance Flow Analysis, this study identifies and quantifies anthropogenic  carbon flows between the sectors set out by  the 2006 IPCC Guidelines for National Greenhouse Gas Inventories; (i) Agriculture, Forestry and Other Land Use (AFOLU), (ii) Industrial Processes and Product Use (IPPU), (iii) Energy, and (iv) Waste. The study also regards imports, exports, extractions from the lithosphere, and emissions to the atmosphere. Furthermore, the study analyses and visualises how carbon flows between different activities within each above-mentioned sector.  The major identified carbon flows occur in the Energy sector, the IPPU sector, and the AFOLU sector. In the Energy sector,  transportation  and  electricity production  &amp;  domestic heating  are  the main contributing activities to emissions of carbon, and in the IPPU sector, industrial processing is subjected to the largest carbon flows. The carbon flows related to  the  transportation,  electricity production  &amp; domestic heating and  industrial  processing activities depend largely on fossil carbon. Targeting these activities with  measures to reduce fossil fuels could potentially have  positive trade-off effects on the Swedish  anthropogenic  carbon system.  The forestry activity in the AFOLU sector  act as an important carbon sink, through capturing significant amounts of carbon each year.  The  result  from this study  provides  a holistic  visualisation  of the  Swedish carbon flows, sources and sinks that occur from anthropogenic activities. It  can be used as tool to describe the relation between different sectors and activities, and it contributed to an understanding of the functioning of the Swedish anthropogenic carbon system. / Kol (C) är en väsentlig beståndsdel för allt liv. Modern  boskapshållning och användning av kol genom förbränning av fossila bränslen leder dock till ökade koncentrationer av koldioxid och metan i atmosfären, två viktiga växthusgaser (GHG). Stigande koncentrationer av växthusgaser i atmosfären är en av världens mest akuta frågor och leder till stigande globala temperaturer. Nationer världen över kämpar för att nå nettonollutsläpp av koldioxid och Sverige har satt som mål att ha nettonollutsläpp till 2045. För att nå detta mål krävs flera systemförändringar inom alla sektorer i Sverige Syftet med denna studie är därmed att ge en helhetsbild av antropogena kolflöden, källor och sänkor i Sverige, vilket kan bidra till en bättre förståelse för  det antropogena kolets kretslopp i det  svenska  systemet. Detta görs genom att kvantifiera de viktigaste antropogena kolkällorna, flödena och sänkorna, och visualisera dem i ämnesflödesscheman.  Resultaten från denna studieger  därmed  insikt i  det svenska  antropogena kolkretsloppet. Genom tillämpning av ämnesflödesanalys identifierar och kvantifierar denna studie  antropogena kolflöden mellan de sektorer som anges i 2006 års IPCC:s riktlinjer för nationella inventeringar av växthusgaser; (i) Jordbruk, skogsbruk och annan markanvändning (AFOLU), (ii) Industriella processer och produktanvändning (IPPU), (iii) Energi och (iv) Avfall. Studien omfattar även import, export, utvinning från litosfären och utsläpp till atmosfären. Vidare analyserar och visualiserar studien hur kol flödar mellan olika verksamheter inom varje ovan nämnda sektor. De största identifierade kolflödena förekommer inom energisektorn, IPPU-sektorn och AFOLU-sektorn. Inom energisektorn är transporter  samt  elproduktion och uppvärmning de huvudsakliga bidragande aktiviteterna  till utsläpp av kol, och inom IPPU-sektorn  står industrier  för de största kolflödena. Kolflödena relaterade till transporter, elproduktion och uppvärmning,  samt  industriell bearbetning beror till stor del på fossil energi. Riktade åtgärder för att minska användningen av fossila bränslen inom dessa  aktiviteter  kan potentiellt ha positiva effekter  på det svenska  antropogena kolkretsloppet. Skogsbruk i AFOLU-sektorn fungerar som en viktig kolsänka genom att fånga upp betydande mängder kol varje år. Resultatet från denna studie ger en holistisk visualisering av de svenska kolflöden, källor och sänkor som uppstår från antropogen verksamhet. Den kan användas som ett verktyg för att beskriva relationen mellan olika sektorer och verksamheter och bidra till en förståelse för det svenska antropogena kolets kretslopp.

Engineering research and development work is undergoing a reorientation from focusing on specific parts of different systems to a broader perspective of systems level, albeit at a slower pace. This reorientation should be further developed and enhanced with the aim of organizing and structuring our technical systems in meeting sustainability requirements in face of global ecological threats that have far-reaching social and economic implications, which can no longer be captured using conventional approach of research. Until a list of universally acceptable, clear, and measurable indicators of sustainable development is developed, the work with sustainability metrics should continue to evolve as a relative measure of ecological, economic, and social performance of human activities in general, and technical systems in particular. This work can be done by comparing the relative performance of alternative technologies of providing the same well-defined function or service; or by characterizing technologies that enjoy different levels of societal priorities using relevant performance indicators. In both cases, concepts and methods of industrial ecology play a vital role. This thesis is about the development and application of a systematic approach for the assessment of the performance of technical systems from the perspective of systems analysis, sustainability, sustainability assessment, and industrial ecology. The systematic approach developed and characterized in this thesis advocates for a simultaneous assessment of the ecological, economic, and social dimensions of performance of technologies in avoiding sub-optimization and problem shifting between dimensions. It gives a holistic picture by taking a life cycle perspective of all important aspects. The systematic assessment of technical systems provides an even-handed assessment resulting in a cumulative knowledge. A modular structure of the approach makes it flexible enough in terms of comparing a number of alternatives at the same time, and carrying out the assessment of the three dimensions independently. It should give way to transparent system where the level of quality of input data can be comprehended. The assessment approach should focus on a selected number of key input data, tested calculation procedures, and comprehensible result presentation. The challenge in developing and applying this approach is the complexity of method integration and information processing. The different parts to be included in the same platform come in with additional uncertainties hampering result interpretations. The hitherto tendency of promoting disciplinary lines will continue to challenge further developments of such interdisciplinary approaches. The thesis draws on the experience from ORWARE, a Swedish technology assessment tool applied in the assessment of waste management systems and energy systems; and from the EcoEffect tool used in the assessment of building properties; all assessed as components of a larger system. The thesis underlines the importance of sustainability considerations beginning from the research and development phase of technical systems. The core message of this thesis is that technical systems should be researched as indivisible parts of a complex whole that includes society and the natural environment. Results from such researches can then be transformed into design codes and specifications for use in the research and development, planning and structuring, and implementation and management of technical systems. / QC 20100505

Aquaculture has been a way to produce fish as a protein source for thousands of years and over the past decades aquaculture has been the fastest expanding animal-based food sector in the world. This study focused on quantifying the flows of nitrogen and phosphorus in Atlantic Salmon farming and compared traditional open net farming with a more recent technique, land based recirculating aquaculture system (RAS). The aim was to quantify the difference in emissions of nitrogen and phosphorus between the two types of farming and to quantify the amount of nutrients that could be reused from the respective fish farm. Data were obtained from reports, scientific publications and an application for environmental permit (EIA) for the case Smögenlax Aquaculture AB. The same feed input and salmon output were assumed in the two systems and a substance flow analysis was used to quantify the flows of nutrients. The amount of produced salmon and fish feed/year were taken from Smögenlax Aquacultures EIA. The results showed that a RAS-based Salmon farm emits only 6 % of the nitrogen and 5 % of the phosphorus emitted to the recipient waters in comparison to an open net farm. RAS-based salmon farming also enables the reuse of 19 % more nitrogen and 47 % more phosphorus than an open net farm by using sludge and fish offal from the farm to create biogas and biofertilizers. RAS is still evolving to provide possibilities for large scale salmon farms on land to be both cost and environmental efficient and may in the future be the most common way to farm Atlantic Salmon.

A turn to more sustainable resources has lead the research during the last decades to algae. Algae is a resource that has been utilized for thousands of years offering a variety of possibilities. Nevertheless modern technology were able to uncover algae’s great potential and pave the way for alternative uses such as biofuel and biomaterial production. Towards that direction, ‘Seafarm’ aims in utilizing algae in the most efficient and sustainable way. For that purpose various steps have been established, including the biorefinery step which entail among other the extraction of carbohydrates from brown algae. The current thesis is based on an extraction of carbohydrates from Saccharina latissima, a brown algae species, which was developed by Viktor Öberg during his master thesis at KTH. The aim of this work is to assist in the scaling up of that laboratory process by analyzing the basic steps and substances of the process, investigating its environmental performance and identifying improvement areas for theoretical optimization. The results of the aforementioned analysis include a substance flow analysis which reveals the basic steps of the process and constitute the basis for further analysis. The second step examines the environmental performance of the process based on the chemical selection. Hence the results are a risk assessment of chemicals with performance indicators for each chemical as well as the whole process. The final part provides a theoretical optimization of the process based on literature studies where the recommendations are divided in production optimization and environmental performance. The above results constitute the basis of the analysis of the process and sets the foundations for scaling up the process at an industrial level. The current analysis in combination with an energy and economic assessment could be used for the designing of the process and its integration in the biorefinery.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第19986号 / 工博第4230号 / 新制||工||1654(附属図書館) / 33082 / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 酒井 伸一, 教授 米田 稔, 准教授 平井 康宏 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Human food consumption has changed from the late 19th century to the turn of the millennium, and so has the need for resources to sustain this consumption. For the city of Linköping, situated in southeastern Sweden, the environmental imprint of an average inhabitant’s food consumption is studied from the year 1870 to the year 2000. The average consumer is the driving factor in this study, since changes in food consumption have a direct influence on the environmental imprint. This thesis analyses the environmental imprint of human food consumption from a historical perspective, by applying two different methods. An analysis of the average Swedish food consumption creates the basis for a material flow analysis of nitrogen and phosphorus, as well as a study of the spatial imprint. Emissions of nitrogen and phosphorus into the hydrosphere have decreased over this period for the system of food consumption and production for an average consumer, while the input via chemical fertilizer has increased significantly. The efficiency of this system could be increased if for instance more phosphorus in human excreta would be reused within the system instead of large deposition and losses into the hydrosphere. The spatial imprint of human food consumption shows, given the changing local preconditions, that less space would be needed for regional production of the consumed food. However, the share of today’s import and thus globally produced food doubles this spatial imprint. The results of this study show not only a strong influence of the consumption of meat and other animal products on the environmental imprint, but also great potential in the regional production of food. In the context of an increasing urban population, and thus additional billions of people who will live at an increasing distance from the agricultural production land, concern for the direct effects of our human food consumption can be of decisive importance for future sustainable food supply.