Stora mängder energi lämnar bostäder med avloppsvattnet utan något bemödande att återföra det uppvärmda vattnets värmeenergi tillbaka till byggnaden. Med ökade klimatskalsförbättringar av traditionellt slag för att möta de nära-nollenergikrav på nybyggnationer för bostadshus som träder i kraft i slutet av 2020 kan energiförlusterna i byggnader till allt större del allokeras till det avloppsvatten som lämnar byggnaden. Målet med detta arbete är att undersöka huruvida betydande energibesparingar inom området kan erhållas, samt att bedöma de ekonomiska möjligheterna och utsikterna för att tillvarata värmeenergi med hjälp av värmepump ur gråvatten från  flerbostadshus uppkopplade mot fjärrvärmenät. Och i och med det visa vilka faktorer som visar sig utöva påverkan på de driftmässiga besparingsmöjligheterna samt uppvisa hur pass känsligt resultatet är i förhållande till ett urval av dessa faktorer. Arbetet utgörs av och har genomförts i två delar: en litteraturstudie och en beräkningsstudie. Avloppsvatten kan delas in i spillvatten, dagvatten och dräneringsvatten. Spillvatten är avfallsbidraget från hushåll och andra fastigheter till avloppet. Hushållens spillvatten kan i sin tur indelas i gråvatten och svartvatten. Gråvatten är det vatten som kommer från bad, disk och tvätt, vilket av det skälet även kallas BDT-vatten. Svartvatten är det vatten som spolas ut från toaletter, och kallas därför även klosettvatten. Vid separerade flöden infinner sig möjligheten att tillvarata värmeenergi direkt från gråvatten, som också är den varmare, volymmässigt största och mer lätthanterliga fraktionen, både ur vattenrenings- och värmeåtervinningssynpunkt. Studier på källsorterande system visar på flera fördelar i stort med att hålla hushållens avloppsflöde separerade, såsom bland annat utökad resurseffektivitet av kväve och fosfor vid reningsverken. Nedsmutsning av värmeväxlarytor, i synnerhet av biofilm, utgör en utmaning då avloppsvatten ska användas som värmekälla och är något som måste beaktas även vid tillvaratagande av värme ur gråvatten. Resultatet från beräkningsstudien av ett enskilt fall med tappvarmvattenförvärmning, givet en rad antaganden, gav en driftmässig kostnadsbesparing på cirka 31 000 kr per år och ett nuvärde på dessa årliga besparingar sett över 20 år på cirka 355 000 kr. Energibesparingen uppgick till cirka 63 000 kWh per år vilket innebär en minskning av totala behovet av köpt energi för tappvarmvattenproduktion med cirka 67 % vid uppvärmning av tappvarmvatten till 55 °C. Känslighetsanalysen visar att avgörande parametrar i beräkningsstudien såsom el- och fjärrvärmepris, värmepumpens livslängd och kalkylräntan medför relativt stora förändringar av resultatet om de tillåts att variera. Det är uppenbart att det finns stora mängder energi att återvinna, det är också uppenbart att svårigheter gör att gråvatten som värmekälla inte kan behandlas lättvindigt då bland annat den långsiktiga utvecklingen av vattenanvändningen och hög föroreningsgrad är faktorer som måste beaktas i tillägg till de faktorer som tas upp i känslighetsanalysen. Dubbla system med fjärrvärme och värmepump innebär en högre investering men är samtidigt något som kan ses som ett verktyg för att utnyttja de ökande energiprisvariationer som en allt större andel förnybar icke-reglerbar elproduktion sannolikt innebär genom att helt enkelt kunna variera uppvärmningssätt efter varierande energipriser och finna optimal andelsfördelning. För en fastighetsägare blir det i takt med en sådan utveckling alltmer gynnsamt att kunna välja det som för tiden är det billigaste alternativet. / Large amounts of energy leave homes with wastewater without any effort to return the heated water's thermal energy back to the building. With increased thermal envelope improvements of a traditional nature to meet the nearly zero-energy requirements for residential buildings that will come into effect by the end of 2020, energy losses in buildings can increasingly be allocated to the wastewater leaving the building. The aim of this work is to investigate whether significant energy savings in the mentioned area can be obtained, as well as to assess the economic opportunities and prospects for utilizing heat energy from grey water from multi-residential buildings connected to district heating networks with the help of a heat pump. And by that show which factors are shown to influence the operational savings and how sensitive the results are in relation to a selection of these factors. The work consists of and has been carried out in two parts: a literature study and a calculation study. Household wastewater can be divided into grey and black water. Grey water is the water that comes from bath, dishes and laundry and black water is the water that is flushed out of the toilets. Separated flows reveal the possibility of utilizing thermal energy directly from grey water, which is also the warmer, volume largest and more manageable fraction, both from a water purification and heat recovery standpoint. Studies on source separated systems show a wide range of benefits, largely by keeping household wastewater separated, such as increased resource efficiency of nitrogen and phosphorus at the wastewater treatment plants. The contamination of heat exchanger surfaces, especially biofilm, poses a challenge when wastewater is used as a heat source and is something that has to be taken into account even when using grey water as a heat source. The result of the calculations of an individual case with preheating of domestic hot water, given a series of assumptions, resulted in operational cost savings of approximately SEK 31,000 per year and a present value of these annual savings over 20 years of approximately SEK 355,000. Energy savings amounted to approximately 63,000 kWh per year, which means a reduction of the total need for purchased energy for domestic hot water production by 67 % with an assumption of a final domestic hot water temperature of 55 °C. The sensitivity analysis shows that crucial parameters in the calculation study such as electrical and district heating price, heat pump life and discount rate entail relatively large changes in profit if allowed to vary. It is obvious that there are large amounts of energy to potentially recycle. It is also obvious that difficulties cause grey water as a source of heat not be treated easily because, among other things, the long-term development of household water use and high pollution rates are factors that must be considered in addition to the factors brought up in the sensitivity analysis. District heating and heat pump combined imply a higher investment than a single heating system, but at the same time is something that can be seen as a tool for utilizing the assumed increasing energy price variations that an increasing proportion of intermittent renewable power generation implies simply by varying heating configuration with changes in energy prices and finding the optimal share. For a property owner, it would at this point be favorable to be able to choose what the cheapest option is currently.

I dagsläget står VafabMiljö inför en utveckling av sin verksamhet för att i framtiden kunna nå högre upp i avfallstrappan. För att få en bättre och mer miljösäker avfallshantering i regionen har VafabMiljö påbörjat arbetet med att ta fram en ny avfallsplan. Denna avfallsplan ska skapa en gemensam plattform för alla kommuner i förbundet och ska bidra med förståelse för avfallsfrågor bland regionens invånare. VafabMiljö har ett mobilt Återbruk som åker runt och besöker mindre orter i regionen och samlar in hushållens grovavfall och farliga avfall. En del av den nya avfallsplanen är en utvärdering av det mobila Återbruket för att se dess framtida potential. Detta examensarbete syftade till att studera det mobila Återbrukets historik, nuläge samt att studera andra system i landet. Syftet med den historiska tillbakablicken var att få en inblick i systemets uppkomst och utveckling över tid. Nulägesanalysen syftade till att beskriva den nuvarande verksamheten med avseende på utformning, erfarenheter från personal och besökare, insamlade mängder samt finansiering och kostnader för det mobila Återbruket. Information om det mobila Återbruket erhölls från VafabMiljö samt från personal ute på plats. Andra orter och kommuner kontaktades för att få information om deras insamlingssystem och för att få inspiration till förlag och komplement till framtida förbättringar på det mobila Återbruket. Resultatet av examensarbetet påvisade att det mobila Återbruket är ett väl utvecklat system som ligger i nivå med andra lösningar för mobil avfallsinsamling i landet. Det mobila Återbruket visade sig vara uppskattat ute i regionen och det har en stor utvecklingspotential. Examensarbetet rekommenderar att VafabMiljö bör fortsätta sitt arbete med det mobila Återbruket och det lyfter även fram flera förbättringsåtgärder. Bland annat rekommenderades att det mobila Återbruket borde få en mer bestående profil samt en fraktion för återbruksmaterial. Det rekommenderades även att VafabMiljö borde använda sig av nya informationskanaler för att nå regionens invånare och att de borde göra en vidare undersökning ifall dagens uppställningsplatser är de mest optimala. Flera av de föreslagna komplementen syftade till att underlätta avfallshanteringen för regionens invånare och kommer därmed hjälpa VafabMiljö att nå högre upp i avfallstrappan. / At present, VafabMiljö is facing a business development in order to reach higher in the European waste hierarchy. They have therefore begun the work of a new waste plan in order to get a better and a more environmentally safe waste management. This management plan will create a common platform for all municipalities in the federation and will contribute to the understanding of waste issues among regional residents. VafabMiljö has a Mobile-recycling centre that travels around in the region and collects household waste and hazardous waste. A part of the new waste plan is an evaluation of the Mobile-recycling centre in order to evaluate its potential. This thesis included an evaluation of the system’s history, a situation assessment and a study of other waste systems in Sweden. The purpose of the historic review was to get an insight into the system’s origin and development over time. The situation assessment was aiming to describe the current system relating to design, experiences from the staff and visitors, collected volumes, costs and revenues. Information about the Mobile-recycling centre where received from VafabMiljö and other municipalities were contacted to get information about their waste collection systems. The experiences from other systems in the country were used to get inspiration for future improvements of the Mobile-recycling centre. The results of the thesis showed that the Mobile-recycling centre is a well-developed system. The visitors at the recycling centre appreciated the solution and it has a great development potential. This thesis recommends that VafabMiljö continue their work with the Mobile-recycling centre and the thesis highlighted several improvement measures that was inspired from other systems in the country. Among other things, it where recommended that the Mobile-recycling centre should have a more permanent profile and it was recommended that it should have a material fraction for reuse. The thesis also recommended that VafabMiljö should use new information channels and that they should make further examinations of whether today´s locations are the most suited. Several of the proposed complements aims to facilitate waste management for the region's inhabitants and therefor help VafabMiljö to reach higher in the European waste hierarchy.

This thesis is about Circular Economy and sustainability through a retailer’s perspective. There has also been a focus on researching and trying to find out if the size of the retailer matters in a sustainability perspective and to achieve a Circular Economy. The research that has been made is done with a deductive approach and a qualitative method. Interviews have been held over a timeframe of a week in May 2020. Because of the pandemic, Covid-19, all of the interviews were held over telephone or email to ensure safety for all respondents, including the safety for the authors. The theory chapter has been conducted through peer-reviewed articles and literature. This chapter has then been divided into smaller parts chapters, as Circular Economy, Sustainability and Supply chain, and Triple bottom line. After the theory chapter the method in how the research have been done and why specific methods have been preferred over others. Following chapter is the empirical findings bundled together with analysis, each interview comes first separately and divided in the same way as the theory and are then compared in an analysis. The conclusion is that retailers need to continue working to become more sustainable. A way for retailers to present their work towards Circular Economy and sustainability is to be transparent and will reach consumers’ which can lead to higher reliability. There is a difference between larger and smaller retailers, it is in how the larger retailers have worked more towards incorporate Circular Economy model and sustainability in comparison to the smaller retailers.

Under de senaste decennierna har textilindustrin bevittnat en ökad medvetenhet gällandehållbarhet. Redan 2010 nämner Karl-Johan Persson, före detta VD för H&M, att hållbarhet är en naturlig del av att göra affärer i en globaliserad värld (H&M 2010). Trots att detta uttalades redan för ett decennium sedan, kan det än idag ifrågasättas ifall textilindustrin verkligen har utvecklat någon realistisk lösning. Allt fler så kallade "hållbara affärsmodeller “tillkommer inom modebranschen, men tyvärr kan ordet "hållbarhet" ibland användas som ett generellt container begrepp utan att betona de faktiska aspekterna som hållbarhet inkluderar(Van Weele 2014). Syftet med denna kvalitativa studie är att undersöka svenskaproduktutvecklande företag och analysera dess bakomliggande motiv, implementeringsprocesser och genererade effekter som kan ses vid användning avhållbarhetsaktiviteterna återvinning (recycle), återanvändning (reuse) och Life CycleAssessment (LCA). Följaktligen ämnar studien till att skapa en djupare förståelse för länken mellan företags existerande affärsmodell och valda hållbarhetsaktiviter. För att besvara studiens forskningsfrågor har en kvalitativ forskningsstrategi tillämpats, där studiens empiriska information samlats in genom semi-strukturerade intervjuer med svenskaproduktutvecklande företag. Avsikten är således att forma sammanhängande tolkningar av studiens insamlade data för att därigenom skapa ett resultat som kan användas praktiskt i vidare studier och aktiviteter inom området. Studiens resultatet tyder på att företagens motiv kan kategoriseras inom de tre fundamentenligt modellen Triple Bottom Line; (1) ekonomiskt, (2) socialt och (3) miljömässigt. Ytterligare kategorisering sågs för (4) motiv avseende varumärke. Vidare kan det konstaterasatt olika hållbarhetsaktiviteter kräver olika implementeringar, samt att inga stora åtgärder i dagsläget har skett inom företagens befintliga affärsmodeller under implementering. Följaktligen, efter implementering av vald hållbarhetsaktivitet, har ekonomiska, sociala, miljömässiga samt effekter avseende varumärket uppstått. Vidare visar studien att hållbarhetsaktiviteter eventuellt bör implementeras och prioriteras olika utifrån verksambransch. Det är därmed av rekommendation för praktiker inom arbets- och sportbranschen att fokusera på LCA, då studiens empiri har konstaterat att återvinning och återanvändning inte är lämplig för dessa produktkategorier. Det kan även rekommenderas att modebranschen prioriterar återanvändning före återvinning. Dels på grund av att återvunna plagg ofta har en kortare livscykel beroende på sämre kvalitet, men även på grund av att det är en meravancerad hållbarhetsaktivitet i jämförelse med återanvändning. Slutligen kan denna studiedra kopplingen att det blir betydligt viktigare att utföra en LCA på produkter som ej kan återanvändas eller återvinnas. / In recent decades, the textile industry has witnessed an increased awareness of sustainability. Already in 2010, Karl-Johan Persson, former CEO of H&M, mentioned that sustainability is a natural part of doing business in a globalized world (H&M 2010). Although this was stated a decade ago, it can still be questioned today if the textile industry has really developed any realistic solution. More and more so-called "sustainable business models" are emerging within the industry, but unfortunately the word "sustainability" can sometimes be used as a general container concept without emphasizing the actual aspects that sustainability includes(Van Weele 2014). The purpose of this study is therefore to investigate Swedish product development companies and analyze its underlying motives, implementation processes and generated effects that can be seen when using the sustainability activities recycling, reuse and Life Cycle Assessment (LCA). Accordingly, the study aims to create a deeper understanding of the link between existing business models and selected sustainability activities, which is required in previous research. To answer the study's research questions, a qualitative research strategy was applied, in which the study's empirical information was collected through various semi-structured interviews with Swedish product development companies. The intention is therefore to try to implement coherent interpretations of the study's collected data, in order to obtain a result that can be practically used in further studies and activities in the field. According to the study's results, the companies' motives can be categorized into the three foundations according to the Triple Bottom Line model; (1) economically, (2) socially and(3) environmentally. Further categorization was seen for (4) trademark motifs. Furthermore, it can be noted that different sustainability activities require different implementations, and that no major measures have been taken within the companies' existing business models during implementation. After implementation of a chosen sustainability activity, economic, social, and environmental effects regarding the brand have arisen. Finally, the study considers that sustainability activities should be implemented and prioritized differently based on industry. It is therefore a recommendation for practitioners in the work and sports industry to focus on LCA, as the study's empirical findings have found that recycling and reuse are not suitable for these product categories. Furthermore, it is recommended that the fashion industry prioritize reuse before recycling. Partly because recycled garments often have a shorter life cycle due to poorer quality, but also because it is a more advanced sustainability activity compared to reuse. As a result, this study can draw the link that it becomes significantly more important to perform a LCA on products that cannot be reused or recycled. The thesis will be given in Swedish.

It is generally accepted that a decrease in temperature causes the rates of chemical and biochemical reactions to slow down, usually resulting in poorer performance of biological wastewater treatment systems. Despite this, early researchers repeatedly showed that excess biological phosphorus removal (EBPR) was more efficient at colder temperatures. Recent studies, however, have demonstrated that the reaction rates of EBPR processes decrease with temperature in accordance with Arrhenius' Law, resulting in an apparent contradiction in the literature. The objective of this study was to investigate the EBPR temperature controversy. The experimental systems used were two, lab-scale UCT configuration plants fed with acetate as the sole volatile fatty acid (VFA) source. The results showed that EBPR systems do perform more efficiently at colder temperatures, i.e., at 5°C compared to 20°C. The reason for better system performance was determined to be related to reduced competition for substrate in the non-oxic zones that results in an increased population of phosphate accumulating organisms (PAOs) relative to non-PAOs and, therefore, greater EBPR efficiency even though the reaction rates are slower. The proliferation of PAOs relative to non-PAOs at cold temperature indicates that some of the PAOs are psychrophilic, i.e., they have alternate biochemical pathways that give them a competitive advantage over bacteria dependent upon glycogen metabolism. The activated sludge acclimated to 20°C had relatively high polyhydroxyvalerate (PHV) and glycogen contents relative to sludge acclimated to 5°C. It was initially hypothized that there is a significant competition between PAO and glycogen accumulating organisms (GAOs) at 20°C and cold temperature (5°C) nearly eliminates this competition in favor of the PAOs. A series of batch test experiments revealed that despite similar acetate utilization by the sludges grown at the two temperatures nearly 30% less PHA was produced by the sludge taken from the 20°C reactor, indicating that GAOs were a small fraction of the population at 20°C. Transmission electron microscopy pictures showed that the biomass acclimated to 20°C had a much more diverse bacterial population than the biomass acclimated to 5°C. However, no GAO population was detected in electron microscopy samples under any temperature conditions. The decreased P removal efficiency at 20°C was then attributed to the presence of fermentative or other non poly-P bacteria that are capable of utilizing substrate under anaerobic conditions. PHA production greatly increased at 5°C, whereas glycogen metabolism substantially reduced. Even though glycogen is an essential requirement for EBPR mechanism, the EBPR microorganisms have the ability to adapt their metabolic pathways to environmental conditions and greatly reduce their need for glycogen. It is apperant that cold temperature inhibits some of the key enzymes in glycogen metabolism resulting in lower glycogen accumulation that in turn increases the EBPR performance. Therefore temperature not only exerts selective pressure on the dominant population but also alters the metabolic pathways of the EBPR process. Increased glycogen accumulation, as observed in this study at 20°C, may not be related to GAO proliferation as suggested by Filipe et al. (2001) instead it may be related to EBPR bacteria to efficiently use glycogen metabolism. Current models (Brdjanovic et al. 1997; Filipe et al. 2002) consider that GAO metabolism is an integral part of EBPR metabolism and the performance of EBPR processes depends on PAO/GAO fraction in the EBPR system. No GAO proliferation was observed even the A/O process was operated without P addition for more than 3 weeks at 10°C. Therefore such important concept should be further investigated before it is included in EBPR models. EBPR stoichiometry was presumed to be insensitive to temperatures (Brdjanovic et al. 1997). However, observed stoichiometric values of PHA storage per unit glycogen utilization and PHA utilization per unit glycogen rephlenishment were quite different at different temperatures. Temperature, therefore, not only affects the kinetics of EBPR systems but also affects the EBPR stoichiometry. Most prokaryotic cells have the ability to alter their cellular membrane fatty acid composition as temperature decreases to counteract the adverse effects of temperature on membrane fluidity (Becker et al., 1996). This unique ability is known as "homeoviscous adaptation". In this study, homeoviscous adaptation by EBPR activated sludge was investigated for a series of temperatures ranging from 20°C to 5°C using one of the lab scale EBPR systems. The fatty acid analysis results showed that the unsaturated to saturated fatty acid ratio increased from 1.40 to 3.61 as temperature dropped from 20 to 5°C. The increased cis-9-hexadecanoic acid (C16:1) at 5°C strongly indicated the presence of homeoviscous adaptation in the EBPR bacterial community. Thus the cell membranes of the EBPR community were still in a fluid state, and solute transport and proton motive force mechanisms were operable even at 5°C. It was concluded that loss of EBPR performance at low temperatures, as reported by McClintock et al. (1992) was not related to the physical state of the cellular membranes, but was probably caused by unsuitable operational conditions. Even though the transport of volatile fatty acids (e.g. acetate) is an integral part of EBPR biochemistry and stoichiometry, this important concept has been ignored. Fleet (1997) concluded that acetate entry into bacterial cells in EBPR sludge was simple passive diffusion based upon the results of a single study (Baronofsky et al. 1984). However, this study showed that neither acetate nor propionate can cross the cell membrane via simple passive diffusion. The existence of apparent saturation curves when the substrate uptake rates (acetate and propionate) were plotted against the substrate concentrations suggested that transport of volatile fatty acids obey facilitated or active transport. Following from the above results, an investigation of the impacts of operational conditions such as low solids retention time (SRT), presence of electron acceptors in the non-oxic zones, low anaerobic detention time, and lack of acclimation was performed. The results showed that the "critical, i.e., wash-out" SRT increased as temperature decreased, but if the biomass was permitted to acclimate to the lower temperature, a major population shift would occur which would increase the capacity of the system for phosphorus (P) removal. When the 5 °C sludge was allowed to acclimate at a relatively high SRT (18 d), the system's P-removal capacity greatly surpassed that of the 20 °C system. The decrease in EBPR performance because of the presence of nitrates in the non-oxic zones was determined to be greater than what would be predicted based on accepted stoichiometry. / Ph. D.

Thesis: Sc. D., Massachusetts Institute of Technology, Department of Chemical Engineering, 1976 / Bibliography: p. 361-366. / Sc. D. / Sc. D. Massachusetts Institute of Technology, Department of Chemical Engineering

To mitigate the global greenhouse gases (GHGs) emissions, carbon dioxide (CO2) capture and storage (CCS) has the potential to play a significant role for reaching mitigation target. Oxy-fuel combustion is a promising technology for CO2 capture in power plants. Advantages compared to CCS with the conventional combustion technology are: high combustion efficiency, flue gas volume reduction, low fuel consumption, near zero CO2 emission, and less nitrogen oxides (NOx) formation can be reached simultaneously by using the oxy-fuel combustion technology. However, knowledge gaps relating to large scale coal based and natural gas based power plants with CO2 capture still exist, such as combustors and boilers operating at higher temperatures and design of CO2 turbines and compressors. To apply the oxy-fuel combustion technology on power plants, much work is focused on the fundamental and feasibility study regarding combustion characterization, process and system analysis, and economic evaluation etc. Further studies from system perspective point of view are highlighted, such as the impact of operating conditions on system performance and on advanced cycle integrated with oxy-fuel combustion for CO2 capture. In this thesis, the characterization for flue gas recycle (FGR) was theoretically derived based on mass balance of combustion reactions, and system modeling was conducted by using a process simulator, Aspen Plus. Important parameters such as FGR rate and ratio, flue gas composition, and electrical efficiency etc. were analyzed and discussed based on different operational conditions. An advanced evaporative gas turbine (EvGT) cycle with oxy-fuel combustion for CO2 capture was also studied. Based on economic indicators such as specific investment cost (SIC), cost of electricity (COE), and cost of CO2avoidance (COA), economic performance was evaluated and compared among various system configurations. The system configurations include an EvGT cycle power plant without CO2 capture, an EvGT cycle power plant with chemical absorption for CO2 capture, and a combined cycle power plant. The study shows that FGR ratio is of importance, which has impact not only on heat transfer but also on mass transfer in the oxy-coal combustion process. Significant reduction in the amount of flue gas can be achieved due to the flue gas recycling, particularly for the system with more prior upstream recycle options. Although the recycle options have almost no effect on FGR ratio, flue gas flow rate, and system electrical efficiency, FGR options have significant effects on flue gas compositions, especially the concentrations of CO2 and H2O, and heat exchanger duties. In addition, oxygen purity and water/gas ratio, respectively, have an optimum value for an EvGT cycle power plant with oxy-fuel combustion. Oxygen purity of 97 mol% and water/gas ratio of 0.133 can be considered as the optimum values for the studied system. For optional operating conditions of flue gas recycling, the exhaust gas recycled after condensing (dry recycle) results in about 5 percentage points higher electrical efficiency and about 45 % more cooling water consumption comparing with the exhaust gas recycled before condensing (wet recycle). The direct costs of EvGT cycle with oxy-fuel combustion are a little higher than the direct costs of EvGT cycle with chemical absorption. However, as plant size is larger than 60 MW, even though the EvGT cycle with oxy-fuel combustion has a higher COE than the EvGT cycle with chemical absorption, the EvGT cycle with oxy-fuel combustion has a lower COA. Further, compared with others studies of natural gas combined cycle (NGCC), the EvGT system has a lower COE and COA than the NGCC system no matter which CO2 capture technology is integrated. / QC 20111123

No description available.

Idag är klimatfrågan ett av världens mest omtalade ämnen. Majoriteten av forskarna runt om i världen är eniga att klimatförändringen är direkt orsakad av oss människor. Detta har gett en insikt om att klimatförändringen är en av mänsklighetens största utmaningar som behöver tas på allvar. Därför behöver vi människor gemensamt enas och ta ansvar för globala lösningar. Idag är den linjära ekonomin klart dominerande, medan det nya motsatta systemet som benämns cirkulär ekonomi blir allt mer eftertraktat. Den cirkulära ekonomin är ett koncept som möjliggör miljöns välmående på ett hållbart sätt. Begreppet handlar om i korthet att återanvända och återvinna produkter, resurser och material på ett sätt som efterliknar naturens egna kretslopp. Begreppet cirkulär ekonomi är väldigt brett och därför har vi valt att avgränsa arbetet till material inom byggbranschen. Syftet med examensarbetet har därför varit att undersöka utmaningar och möjligheter för implementering av cirkulär ekonomi inom byggbranschen. De frågor vi valt att titta närmre på är: Vad finns det för verktyg som kan bidra till cirkulär ekonomi i byggbranschen? Hur arbetar en stor svensk exploatör idag med cirkulär ekonomi? Vi har använt en kvalitativ forskningsmetod för att kunna fördjupa oss inom ämnet. Arbetet består till en stor del av litteraturstudien som bygger på webbkällor med hög trovärdighet. Vi har även intervjuat flera specialister på Riksbyggen. Vi har varit källkritiska och tagit hänsyn till aspekter såsom validitet, reliabilitet och variabilitet. Resultatet tar fram både privata och statliga verktyg men även olika miljöcertifieringar, som är relevanta inom byggbranschen i förhållande till cirkulär ekonomi. De olika verktyg och miljöcertifieringar fungerar på liknande sätt och alla framförs i syfte att främja den cirkulära ekonomin inom byggbranschen. Verktygen som nämns i rapporten har gett goda resultat och etableras mer i byggbranschen. Dock täcker inte ett verktyg eller miljöcertifiering alla aspekter inom cirkulär ekonomi, utan de fungerar bra som utgångspunkter. För att uppnå goda resultat krävs det att man kombinerar olika verktyg eftersom de kompletterar varandra. Slutsatsen är att det är mer effektivt att kombinera de olika verktygen. Detta för att täcka upp fler aspekter inom cirkulär ekonomi. Med god kunskap inom området och effektiv kommunikation mellan aktörer, optimeras resultatet. Därför är ett gott samarbete nyckeln till framgång. / Today, the climate issue is one of the world's most talked about topics. The majority of scientists around the world agree that climate change is directly caused by us humans. This has given us an insight that climate change is one of humanity's greatest challenges that needs to be taken seriously. That is why we need people to come together and take responsibility for global solutions. The linear economy is today clearly dominant, while the new opposite system called circular economy is becoming more sought after. The circular economy is a concept that enables the environment's wellbeing in a sustainable way. In short, the concept is to reuse and recycle products, resources and materials in a way that mimics the nature's own cycle. The notion of circular economics is very broad and that is why we have chosen to limit the work to materials in the construction industry. The purpose of the thesis has therefore been to explore challenges and opportunities for implementing circular economics in the construction industry. The question formulations we have chosen to look at are; What tools are there that can contribute to circular economy in the construction industry? How does a large Swedish operator work with circular economy today? We have used a qualitative research method where we have been able to immerse ourselves in the subject. The work consists largely of the literature study, which is based on sources from various websites with high credibility. We have also interviewed employees at Riksbyggen. We have been critical to sources and have taken into consideration of aspects such as validity, reliability and variability. The result produces both private and government tools as well as various environmental certifications, which are relevant in the construction industry regarding circular economy. The various tools and environmental certifications produced work in a similar way, and all are presented with the aim of promoting the circular economy in the construction industry. The tools mentioned in the report have produced good results and are more established in the construction industry. However, a tool or environmental certification does not cover the entire area of circular economics, but they work well as a starting point. To achieve good results, it is necessary to combine different tools since they complement each other. The conclusion is that it is more efficient to combine the different tools. This is to cover more aspects of the circular economy. With good knowledge in the subject and effective communication between partners, the result is optimized. Therefore, good cooperation is the key to success.

The project focuses on the center of Tensta. The municipality of Stockholm has identified multiple developing areas in Stockholm, one of them being Tensta and especially Tensta centrum.  The main focus of this project is to think about and implement social and environmental sustainability through architecture. A big garage complex sits quite empty in the center of Tensta today, taking up valuable place of the center. In this project the garage complex is disassembled and its parts re- and upcycled to fit a new building in the site. The building's program consists of Järva stadsdelsförvatlning (Järva city administration office), Tensta library and a restaurant. A new square is also designed to make the center of Tensta a more welcoming place.