Nitrogen recovery from wastewater treatment for fertilizers is a research topic that exists at the intersection of multiple topics important to the future of sustainable society. First, nitrogen recovery from wastewater implies a departure from the current methods of nitrogen mitigation, which involve nitrogen removal by conversion of various aqueous species to inert nitrogen gas. Secondly, by recovering nitrogen from wastewater specifically, there is the opportunity to begin a circular economy where value added products can be obtained from material that has historically been seen as a “waste”. Current wastewater treatment involves nitrogen removal through the biological transformation of aqueous nitrogen species to inert nitrogen gas. This process is energy intensive and risks the production of air pollutants such as N2O as intermediates in the biological transformation. If this nitrogen can be captured in a form that can be reused, a valuable product can be achieved with the potential reduction of both the energy required at the wastewater treatment plant as well as the carbon footprint. Finally, by recovering nitrogen in a form that can be used in agriculture as a fertilizer, additional environmental benefits can be realized by reducing reliance on Haber-Bosch based ammonia production, which is also energy intensive and contributes harmful emissions to the atmosphere. The work described in the following licentiate aims to consider the current status of nitrogen recovery from wastewater for fertilizers as a research topic. Literature was analytically examined to compare different techniques in terms of energy requirements, cost for fertilizer production, market for final fertilizer product, and technological readiness. The most interesting findings from this review were that there seems to be a disconnect between the fertilizer product produced by nitrogen recovery techniques and the market, which will become a challenge if these techniques are implemented at a large scale. The attitude of the farmers with regards to fertilizers from waste was overall positive, with their concerns mainly focused on the performance ability and cost of the product. Additionally, many techniques such as microbial fuel cells and microbial electrolysis cells have been unable to move past the laboratory phase despite being researched for many years. This indicates there are cost and technological barriers that are preventing the further scale up and implementation of these techniques. Energy and cost analyses will be crucial to motivate investment into these processes, and these are missing for many of the techniques found around this topic. To contribute to this field, experimental work was also included to assess the potential for ammonium adsorption from concentrated wastewater for fertilizer production. The experimental work focused on the utilization of the solid product of pyrolysis of sewage sludge (biochar) for adsorption and explored the potential enhancement of the char with various chemical treatments. The char with the best ammonium adsorption performance was found to be using a treatment of HNO3 followed by and NaOH, with an adsorption capacity of 4 mg NH4/g biochar. This char was compared with commercially activated carbon and clinoptilolite for full scale applications. It was found that even with this increased adsorption capacity, the use of chemically enhanced sewage sludge biochar for full scale applications is not realistic. The amount of raw material required for the complete recovery of ammonium from reject water at the municipal wastewater treatment plants exceeds the total amount of sewage sludge generated. Therefore it is recommended that the goal of incorporating sewage sludge biochar with wastewater treatment is to produce a solid fertilizer product loaded with ammonium (which would provide ammonium-N and phosphorus for plant growth, as well as carbon and other minerals for soil amendment) rather than having the goal be complete ammonium recovery from the wastewater stream.

PFAS (per- and polyfluoroalkyl substances) are a large group of substances that are used in a large variety of products because of their unique water and dirt repellent properties. The substances are extremely persistent and can spread over large distances in groundwater, surface water, and in the air, which makes them an environmental and a health concern. A significant pathway of PFAS into the environment is through wastewater, where the usage of consumer products containing PFAS contribute to the emissions. The project was performed by analysing data of PFAS concentrations in wastewater and sludge sampled continuously during 2022 at Uddebo wastewater treatment plant (WWTP) in Luleå municipality. The aim was to evaluate the composition of PFAS compounds and their concentrations in wastewater and sludge and compare with other municipalities, to analyse how PFAS concentrations change during the existing wastewater treatment process, and to suggest strategies for future treatment of PFAS in wastewater.  No significant change of the PFAS content in wastewater could be observed throughout the treatment process in Uddebo WWTP. Evaluation of the PFAS composition showed that PFOS was the most abundant substance in both water and sludge. Over the year some variations in the total PFAS concentration could be seen, which coincided with increased water flow during the snowmelt period and an operational disturbance at the treatment plant. The variations of the total PFAS concentrations in wastewater over the year were mainly caused by PFBA, PFOS and 6:2 FTS. Analysis of total oxidizable precursors in the wastewater showed that substances that can transform into more persistent PFAS are present in the incoming water to the plant to a large extent. The pilot plant designed for treatment of pharmaceuticals, including ozonation and a granular activated carbon filter, did not result in any separation of PFAS from the water. An assessment of the contribution of PFAS from landfill leachate showed that it constitutes a significant share of the total PFAS content in wastewater. Compared with the content of PFAS in other Swedish WWTPs the total concentrations in wastewater at Uddebo WWTP was among the highest of five compared municipalities, while Luleå had the lowest PFAS concentrations in sludge among two compared municipalities.  The comparison between municipalities was limited by large differences in sampling frequency and performed analyses between the municipalities. Standardised analyses, additional background information, and more detailed statistical analyses are necessary to be able to make this type of comparison more informative. The occurrence of PFOS, which have been globally banned since 2009, shows that restrictions of the usage of PFAS must be combined with treatment of contaminated media to reduce the concentrations of PFAS in the environment. Development of PFAS degradation techniques is vital to remove PFAS from circulation. The difficulties of treating large amounts of water with low concentrations motivates investigations concerning if treatment of smaller water flows with higher PFAS concentrations is a better alternative than implementing treatment of the total amount of water that reaches the WWTP.

Per- and polyfluoroalkyl substances (PFAS) are a rising topic in the field of contaminated sites around the world, with destruction of these being an area in dire need of innovation. Previous experiments of destructive character have been proven efficient using boron doped diamond electrodes (BDD) in small scale electrochemical cells. Further need for experimentation on actual site conditions is needed to further evaluate the use of this method, as well as research on alternative electrode materials to reduce the cost of remediation.  In this study, four cells containing contaminated soil were used: one with BDD electrodes, one with iron electrodes and two control cells. The iron electrodes were used to investigate if a less costly electrode material could achieve any degree of PFAS degradation. For the experiment a soil from a previous firefighting training site where firefighting foam containing high amounts of PFAS (620                     g/kg soil concentration) was used. During the first phase of the experiment a constant flow of deionized water was added to the cells containing the soil, and porewater was sampled at the in- and outflow along with the soil porewater, on a weekly basis, to evaluate the distribution of PFAS to provide information about possible degradation taking place. The extent of degradation was not quantified. However, due to differences in the molecular composition of the analysed PFAS a trend where short-chain PFAS increase throughout the experiment in the BDD cell indicated that short-chain PFAS were generated, which is an expected by-product in electrochemical oxidation of PFAS. No short-chain PFAS generation was seen in the iron electrode cell, nor was there a high amount present in the control cell leachate.  Further, leaching of PFAS was more efficient in the control cells, while PFAS in the BDD and iron electrode cell were retained or leaching was slowed down, most likely due to the electrode interaction with PFAS in porewater.Additionally a second phase where water flow through was halted and the cells were run in a batch mode was conducted to see PFAS degradation in stagnant conditions over time. In the stagnant cell in the second phase, only low PFAS concentrations in porewater were recorded while no degradation was established.  Further, fluoride analysis recorded F- concentrations in the range of    M, where the limit of detection was   M, which limited the confirmation of PFAS mineralisation in soil.  From this study insight of the difficulties with soil treatment of PFAS using electrokinetic method was highlighted, with sampling being a key factor in the accuracy of the result. For a more accurate establishment of the degradation experiments in a closed cell, with more extensive sampling throughout the entire column would be necessary. This is needed to generate a clearer picture of changes in PFAS concentration in the soil from the presumed degradation, coupled with a mass balance to provide the fate of PFAS in this type of setup.

As wastewater treatment plants transition to water resource recovery facilities, the need for improved control and consequently supervision increases. Despite the large volume of research that has been performed on this topic, the use in industry is scarce. Practical implementation is challenging due to the nature of the process, and a lack of standardisation in the research results in uncertainty as to the state of the art. This is one of the main challenges identified.  Experimental work is performed using the Benchmark Simulation Model No. 1 to identify monitoring requirements and evaluate the performance of univariate fault detection methods. For the former, residual based process fault signatures are used to determine minimal sensor requirements based on detectability and isolability goals. Sensor faults are the focus of the latter issue, using the Shewhart, cumulative sum, and exponentially weighted moving average control charts to detect bias and drift faults in a controlled variable sensor.  The use of a standard model and known fault detection methods is useful to establish a baseline for future work. Given the lack of standardised use in industry this is considered critical. Both proposed methods emphasise ease of visualisation which is beneficial for industrial implementation.

With the aim of designing an infrasound-integrated technology which can enhance the algae drying performance, this thesis provided the theoretical possibility of using infrasound as an algae dehydration technology. To test the relation between algae drying speed and other three parameters namely sound frequency, sound pressure and sample mass, four major experimental groups including initial experiments and core experiments with fifteen sub-experimental groups are designed. Results of the experiments shows expected accordance with the theoretical inferences of infrasound being an algae drying technology. Experiment steps and specifications are presented as the research methodology. A real system with the drying capacity of 2 ton fresh algae per day are designed based on the experimental calculations and results. Several revisions including air circulation and infrasound resonance are made when scaling up the research from experimental level up to industrial level. Other specifications of the real system design follow the experiment results with regard of the research consistency. Freeze drying technology is selected for the comparative cost analysis including manufacturing costs and energy consumptions. Results shows infrasound-integrated technology has a relatively low energy consumption whereas it costs more manufacturing costs than freeze drying technology. Research assumptions, limitations and recommendations for this research are described in this article. From the author’s perspective, this paper can be used as an initiation and instruction for larger scale researches in regard of infrasound-integrated algae dehydration/drying.

Odlingsallmänningar som odlingsform används i städer runt om i världen. De kan bidra till städer bland annat genom att öka tillgängliga grönområden, skapa mötesplatser för social gemenskap, öka lokal matproduktion samt öka den biologiska mångfalden. Stockholm är en växande stad som blir allt tätare och stadens grönområden utgör en allt viktigare funktion. Rapporten ämnar till att undersöka odlingsallmänningar i Stockholm. Frågeställningarna som undersökts är hur odlare får tillgång till mark och vilka hälsoeffekter odlingarna kan ge upphov till. För att besvara dessa frågor har en litteraturstudie använts samt intervjuer med personer som odlar i odlingsallmänningar i Stockholm, eller som på annat sätt är relaterade till de odlingsinitiativ som undersökts. Totalt har fem olika odlingsinitiativ undersökts. Resultatet visar på att odlingsallmänningar kan ge hälsoeffekter i form av en ökad social gemenskap, tillgång till terapeutiska platser nära hemmet samt en ökad medvetenhet om kosthållning. Resultatet visade även på att odlingsallmänningarna kan utgöra en bra möjlighet till fysisk motion. Alla de studerade fallen hade genomgått olika processer för att få tillgång till mark vilket visar på variationen i både initiativ till odlingarna och hanteringen av markfrågor. De studerade odlingsallmänningarna var placerade både på offentlig och privat mark. Tillgång till mark utgjordes både av initiativtagare som tagit kontakt med markägare för att fråga om tillstånd att bruka marken och en gerillaodling som börjat odla utan tillstånd. Det var även en kommun som genom medborgardialog hittat engagemang för odling samt en mobil odling som flyttat runt på lediga platser i väntan på exploatering. Vilka personer som får tillgång till de identifierade hälsofördelarna skiljer sig något mellan de olika odlingsallmänningarna. Hälsofördelarna som en ökad biologisk mångfald möjliggör gagnar däremot alla i staden. / Community gardening, as a form of cultivation, is used in cities around the world. They can contribute to cities by, among other things, increasing available green areas, creating social community meeting places, increasing local food production, and increasing biodiversity. Stockholm is a growing city that is becoming increasingly denser, and the city's green areas serve an increasingly important function. The report aims to study community gardens in Stockholm. The research questions are how initiative takers gain access to land and what health effects the community gardens can give rise to. A literature study has been used as well as interviews to answer the questions. The interviews were carried out with people who cultivate in community gardens or who are otherwise related to the community gardens that were investigated. Five different community gardens have been studied in total. The results show that community gardens can produce many health effects. They can increase social inclusion, access to a therapeutic place near the home, and raise awareness of diets. The results also showed that the gardens could represent a good opportunity for physical exercise. All the cases studied had undergone different processes to gain access to land, which shows the variation in both initiatives for cultivation and land management. The studied community gardens were located on both public and private land. Access to the land was made up of both initiators who contacted landowners to ask for permission to use the land, a guerrilla garden that started cultivating without a permit, a municipality that found commitment to cultivation through citizen dialogue and a mobile garden that moved around in vacant places in waiting on exploitation. The persons who gain access to the identified health benefits differed slightly between the different community gardens. In contrast, the health benefits that increased biodiversity enables benefit everyone in the city.

Vatten är en livsnödvändig förutsättning för allt levande och förändringar i vattentillgången kan ha förödande konsekvenser. Därför är det viktigt att hitta ett hållbart sätt att konsumera och återanvända vatten på, särskilt i områden med risk för vattenbrist eller vattenkvalitetsproblem. Sandön är en skärgårdsö med speciell natur och denna studie behandlar en undersökning kring möjligheterna för implementering av regnvatteninsamling på ön för att minska grundvattenuttaget. Studien har omfattat en litteraturgenomgång, insamling, sammanställning och bearbetning av digitala data samt en fältstudie för insamling och kontroll av platsspecifika data. Resultatet av studien visar att möjligheterna för implementering av regnvatteninsamlingslösningar på Sandön är god och olika alternativa lösningar för insamling presenteras. Med den mest kostnadseffektiva lösningen blir den möjliga mängd som går att ersätta med regnvatten 26,7 % av hushållets användning under månaderna juni, juli och augusti, beroende på fastighetens storlek och utrymme för uppsamlingstank samt antalet personer. Den begränsande faktorn är inte potentialen på 23 miljoner liter vatten per år, utan uppsamlingstankens volym som är beroende av fastighetens storlek. Den beräknade optimala totala tankvolymen med avseende på nederbörd och vattenanvändning för Sandön är 3 m3. Vad studien också visar är att grundvattenuttaget på sommaren inte kan täckas upp av enbart regnvatten och att ytterligare lösningar krävs. / Water is a critical necessity for all living creatures and changes in the reservoirs may have disastrous consequences. It is important to find a sustainable way to consume and re-use water, especially in areas with a higher risk of water shortageor quality issues. Sandön is an island in the Swedish archipelago with unique nature and this study includes a survey on the possibilities for implementation of rainwater harvesting on the island in order to decrease the groundwater consumption. The study has covered a literature study on books, reports and articles, collection and processing of digital data and a field study was performed. The result of the study shows that the possibilities of implementation of rainwater harvesting solutions on Sandön is good and different system alternatives are presented. With the most cost-effective system the quantity that is possible to replace with rainwater is 26,7 % of the households use during the months of June, July and August, depending on the properties size, space for placement of tanks and the number of people. The limiting factor is not the potential of 23 millions of liters of water per year, but the volume of the storage tank which is dependent on the size of the property. The optimal total tank volume for Sandön is 3 m3. The study also concludes that the water consumption during the summer can not be covered only by the collection of rainwater and additional solutions are needed.

The increasing demand for low carbon technology has increased the demand for some critical materials. Graphite is one of the strategic raw materials defined by the European Union as it is used in the production of for example batteries in electrical vehicles. Natural graphite is extracted through mining and the production is currently located outside the European Union. However, natural graphite deposits exist in for example Sweden. Mining activities can cause environmental issues, e.g. release of metals to the environment. By studying sediment in lakes, the historical element load can be investigated. In the Vittangi area (northern Sweden), a graphite deposit is located close to the natural lake Hosiojärvi. In the area, exploration has been conducted during the last 100 years. The latest exploration was conducted by the company Talga, who is also planning to extract the graphite. The aim of this master thesis is to determine the geochemical processes affecting the mobility of Co, Cu, Ni and Zn in Hosiojärvi, as well as their historical accumulation in the lake. Due to previous exploration in the area, the eventual impact from trace elements related to the bedrock and graphite deposit has also been studied. Based on previous elemental load to the sediment, the future impact until the mine starts have been discussed. The method used for answering the questions have been sampling of sediment, analysing metal concentrations in surface water, groundwater and sediment and dating of the sediment to determine sediment accumulation rate. The study shows that there has been an increase of Co, Ni and Zn to the lake, as the concentrations in the sediment has increased in the upper parts. By looking at those elements, the increase could be explained by the exploration during 1960 – 1970. The sediment is assumed to be in reduced conditions and the zone where redox processes can occur is assumed to be in the interface between the bottom water and the top sediment. In the sediment, framboidal pyrite is formed in the upper and lower parts of the sediment. Analysis on surface water shows that during the last four years, there is an increasing trend of  Co, Ni, Zn and SO4. The groundwater flows through the mineralisation and affects the water quality in Hosiojärvi, as the water quality of the lake has become more similar to the groundwater. The overall conclusion of the study is that the lake has been impacted by the previous exploration and is assumed to continue being affected until the planned mine is starting to operate.

The following study deals with organizational conditions that affect the implementation of municipal environmental strategies. It aims to increase understanding of and contribute with material of empirical studies of implementing the environmental responsibility of municipalities. The aim of the study was to identify how organizational conditions affect the implementation of environmental strategies and to present solutions to how municipalities can handle the challenges that occur when environmental strategy work is to be incorporated and implemented in a municipality. In order to provide answers to whether there were any, and in that case which, organizational conditions that could promote or hinder municipalities' ability to implement environmental strategies, a literature study and a case study of a medium-sized Swedish municipality was conducted with the aim of collecting experience-based knowledge. The result shows that it is difficult to point out the influence of individual organizational conditions on the implementation process, as they interact. However, the implications are that the organization's structure, culture and leadership influence the work process. Limitation of or the uncertainty on access to resources is highlighted as an obstacle in the work with the environmental strategy. It is pointed out that it will most likely not be an increased resource supply, but instead it is necessary to prioritize what the tax money will be used for. Furthermore, the existence of target conflicts has proved to be a challenge that municipalities need to handle. Target conflicts have been spotted between environmental goals and other municipal goals. Because municipalities generally work on the basis of many, and sometimes conflicting, goals, the ability to prioritize is central. To succeed with the environmental work, municipalities are recommended to identify and enable synergies between the environmental goals and other welfare goals.

In recent years the popularity of biofuels has been transformed from a sustainable option fortransportation to a questionable and criticized method. Many reports have therefore beenproduced to view biofuel production from a life cycle perspective; though results may bemisleading. In a number of the reports, biofuel production is viewed in a linear manner, i.e.crops and energy in and biofuel out. However there is a large quantity of material and energyflows associated with biofuel production and these must be accounted for.Industrial symbiosis concepts have therefore been applied in this thesis to the biofuel industryto identify possibilities to improve the material and energy flows. This has been done bymapping the exchanges and thereafter identifying possible synergies between biofuel firmsand with external industries. Examples from regional biofuel synergies and exchanges withindustrial partners have been highlighted. Many of the concepts have led to the identificationof methods for increased integration and improvements, including the use of a renewableenergy provider and the cooperation with external industries. Biofuels have therefore beenfound to profit from wastes, and instead of competition, benefit from one another, contrary tobelief. This leads to an expanded market of raw materials for biofuel production.Benefits do not only occur for the biofuel industry; from the application of biofuels, industrialsymbiosis may gain further benefits. Several new concepts have been produced in this thesisto account for the unique material handling possibilities that biofuel production firmsencompass. These include using biofuels as upcyclers of materials and the use of renewableenergy as a way to improve environmental performance. Furthermore, a classification methodhas been produced to add more detail about individual exchanges for the industrial symbiosisliterature in addition to viewing industrial symbiosis from an expanded system view toinclude exchanges beyond geographic proximity typical to the field.