<p>Plant nutrients are important for all life on earth and are also important as fertiliser infood production all over the world. Because of this, plant nutrients are of great valuebut they also bring problems. As an example, the loss of nitrogen and phosphorusfrom agriculture and urban society's sewage systems contributes to some of today’smajor problems in water environment. Another problem associated with plantnutrients is that finite recourses are used in the production of mineral fertilizers. Forinstance the limited economical life-span of phosphorus rock might lead to globalconsequences such as unequal distribution of the fertilizers which can increase thehunger around the world.In this thesis, laws, taxes, policies and technology that affect the management of plantnutrients have been described to show how the issue is handled today. Interviewswith representatives of some of the organizations whose activities directly, orindirectly, affect the flow of nutrients through the region of Stockholm have also beencarried out to better understand their views on responsibility and today's situation ingeneral. The goal has been to illustrate today's problems and to make an attempt togive examples of what could make the situation more sustainable in the future.</p>

Plant nutrients are important for all life on earth and are also important as fertiliser infood production all over the world. Because of this, plant nutrients are of great valuebut they also bring problems. As an example, the loss of nitrogen and phosphorusfrom agriculture and urban society's sewage systems contributes to some of today’smajor problems in water environment. Another problem associated with plantnutrients is that finite recourses are used in the production of mineral fertilizers. Forinstance the limited economical life-span of phosphorus rock might lead to globalconsequences such as unequal distribution of the fertilizers which can increase thehunger around the world.In this thesis, laws, taxes, policies and technology that affect the management of plantnutrients have been described to show how the issue is handled today. Interviewswith representatives of some of the organizations whose activities directly, orindirectly, affect the flow of nutrients through the region of Stockholm have also beencarried out to better understand their views on responsibility and today's situation ingeneral. The goal has been to illustrate today's problems and to make an attempt togive examples of what could make the situation more sustainable in the future.

<p>Wastewater treatment is increasingly controlled by the Swedish environmental quality objectives, adopted by the Swedish parliament. There is a need for a sewage system that can fulfill stringent requirements concerning the environment, recycling and resource use and hygiene. Additional environmental aspects in recent years are the impact of climate change, new knowledge about the effects of pharmaceuticals in water, the need for improved wastewater treatment and increased recycling of nutrients to agriculture.</p><p> </p><p>This report has, from a future scenario of the year 2050, analyzed seven different systems for wastewater treatment and treatment of compostable biowaste from households in Eskilstuna. A future scenario was chosen based on that within a forty year period new challenges may arise which can result in higher demands on sewage treatment than those we see today. Another reason why the future scenario was established is that changes in wastewater treatment systems are slow to establish.</p><p> </p><p>The analysis is mainly focused on the economical aspects but environmental aspects such as emissions to receiving waters and potential recycling of plant nutrients has also been evaluated briefly. The economical analysis was made from a new construction perspective. The economy model is constructed in Microsoft Office Excel and named URWARE Eko. The report also includes a section based on results from previous system studies.</p><p> </p><p>A target image of Eskilstuna 2050 was initially created. Seven systems were then analyzed based on this target image. The seven different systems could be divided in to three main categories: conventional sewage system that were modified, source separated blackwater systems and a sewage plant with improved treatment technology in the form of membrane technology and reverse osmosis.</p><p> </p><p>The results showed that it differed a factor of 1.9 between the cheapest system (sludge recovery to productive land) and the most expensive (separated blackwater treated in a central treatment facility). All systems have a big recycling potential of phosphorus. Blackwater systems and wastewater plants with membrane technology and reverse osmosis are the best systems for recycling of other nutrients such as nitrogen, potassium and sulfur.</p><p><em> </em></p>

Wastewater treatment is increasingly controlled by the Swedish environmental quality objectives, adopted by the Swedish parliament. There is a need for a sewage system that can fulfill stringent requirements concerning the environment, recycling and resource use and hygiene. Additional environmental aspects in recent years are the impact of climate change, new knowledge about the effects of pharmaceuticals in water, the need for improved wastewater treatment and increased recycling of nutrients to agriculture.   This report has, from a future scenario of the year 2050, analyzed seven different systems for wastewater treatment and treatment of compostable biowaste from households in Eskilstuna. A future scenario was chosen based on that within a forty year period new challenges may arise which can result in higher demands on sewage treatment than those we see today. Another reason why the future scenario was established is that changes in wastewater treatment systems are slow to establish.   The analysis is mainly focused on the economical aspects but environmental aspects such as emissions to receiving waters and potential recycling of plant nutrients has also been evaluated briefly. The economical analysis was made from a new construction perspective. The economy model is constructed in Microsoft Office Excel and named URWARE Eko. The report also includes a section based on results from previous system studies.   A target image of Eskilstuna 2050 was initially created. Seven systems were then analyzed based on this target image. The seven different systems could be divided in to three main categories: conventional sewage system that were modified, source separated blackwater systems and a sewage plant with improved treatment technology in the form of membrane technology and reverse osmosis.   The results showed that it differed a factor of 1.9 between the cheapest system (sludge recovery to productive land) and the most expensive (separated blackwater treated in a central treatment facility). All systems have a big recycling potential of phosphorus. Blackwater systems and wastewater plants with membrane technology and reverse osmosis are the best systems for recycling of other nutrients such as nitrogen, potassium and sulfur.

Övergödning uppstår i en sjö på grund av att det släpps ut för mycket näring till sjön, främst fosfor är ett problem som försämrar miljön i och omkring sjön. Enligt vattendirektivet ska alla sjöars status vara god, vilket medför att en övergödd sjö behöver åtgärdas. Lågflödesmuddring är en metod att bärga det näringsrika sedimentet som orsakar övergödningen. Då sedimentet är näringsrikt, kan det potentiellt vara till nytta i växtodling på land, i stället för att skapa miljöproblem i vatten. Studien har sammanställt erfarenheter från fem olika pilotprojekt där metoden lågflödesmuddring används för att bärga sediment som i projekten har använts i försök för att utveckla någon form av resurs. Erfarenheter från projekten vittnar om att det finns ett försiktigt intresse från olika sektorer i samhället för att återvinna det bärgade sedimentet.  Sedimentets flytande struktur och för att det kan innehålla förorenande ämnen, begränsar möjligheterna till användning. Beroende på vad sedimentet ska användas till hamnar det under olika förordningar i Sverige. / Eutrophication in a lake occurs due to excess nutrients being released into the lake, namely phosphorous is a problem that deteriorates the environment in the lake and its surroundings. All lakes' conditions should have good status in accordance with the Water Framework Directive; thus, a eutrophic lake must be remedied. Slow flow dredging is a method to salvage the nutritious sediment giving rise to eutrophication. Being that the sediment is nutritious, it could potentially benefit agricultural practices on land, instead of constituting an environmental problem in water. The study has summarised knowledge from five different pilot projects where the dredging method has been used to salvage sediment that in the projects has been used in trials in order to develop some kind of resource. Observations from the projects testify to the fact that there is tentative interest from various sectors for the reuse of the salvaged sediment. The sediments' viscous composition and the fact that it may contain contaminants limits the possibilities for its utilisation. Depending on the area of application different Swedish regulations are to be enforced.

Syftet med detta arbete är att ta reda på vilka problem det finns i perennplanteringarna i offentliga miljöer samt hur man kan förebygga problemen och hur man bygger upp växtbäddar för perenner utifrån ett hållbarhetsperspektiv. Undersökningen genomfördes hösten 2011 och baserades på litteratur som böcker, artiklar, faktablad samt intervjuer. I undersökningen ingick fem angränsande kommuner till Gävle samt tre erkända trädgårdsmästare. Utgångspunkten för valet av trädgårdsmästarna var att de skulle ha erfarenhet av att skapa väl fungerande och hållbara exempel på offentliga perennplanteringar i Sverige. Det finns många olika orsaker till att perennrabatterna i våra offentliga miljöer inte ser så attraktiva ut. Oavsett orsak så kan man säga att grundproblemet är bristfällig kunskap och eventuellt brist i kommunikationsleden från ”idé till planta” när det gäller de offentliga planteringarna. Det är många delar som är viktiga i en växtbädd för att perenner, träd och buskar ska kunna etablera sig och utveckla sin prakt år efter år. En av dessa komponenter är en bra jord. Det är viktigt att man väljer en rotogräsfri jord utifrån växtvalet redan från början. Ett av problemen i kommunerna var att fel sorts jord hade använts från början. Trots att alla påstod att de använde sig enbart av rotogräsfri jord i dagsläget så hade de problem med ogräs. Två orsaker till detta kan vara att man väljer fel växter och att skötseln inte fungerar, vilket resulterar i att ogräset tar över. Den perfekta växtbädden, finns den? Eftersom det är naturen vi arbetar med är det svårt att uppnå det ultimata resultatet, men vi kan göra det bästa utifrån förutsättningarna som finns med alla de delar som ingår i en växtbädd.

This thesis assessed the technical and economic premises for installing systems that process manure in order to recover nutrients and inherent energy. The main purpose of recovering nutrients was to extract phosphorus from the manure, so as to be able to distribute more of the manure on the farm without exceeding the phosphorus regulation. Three other scenarios were included as reference; conventional manure handling, solid-liquid separation only and solid-liquid separation including energy recovery. Since most important parameters for modeling scenarios in agriculture are site-specific (e.g. soil type, crop rotation and manure composition), the thesis results were based on a case farm. The case farm is a 675 ha dairy farm with approx. 1400 milking cows, located in Östergötland, Sweden. As for the results, it was first concluded that the central characteristics of manure were the content of dry matter (DM), nitrogen (N), phosphorus (P) and potassium (K). The higher the DM content, the more fuel for energy recovery, and the higher the N:P-ratio, the more on-farm N can be utilized before having to consider the P regulation. The technical premises for farm-scale nutrient recovery were limited to commercial techniques from companies operating in Sweden, and included various possible processing methods, such as; pH modification, anaerobic digestion, coagulation-flocculation, precipitation, filtration and reverse osmosis. However, most methods were either too costly or simply not realistic to install on stand-alone farms, resulting in only two feasible options; struvite precipitation and secondary solid-liquid separation with a decanter centrifuge. The comparison in economic performance for all scenarios resulted as follows: nutrient recovery by struvite precipitation was the most profitable scenario of all, if struvite was allowed to replace mineral P fertilizer (i.e. end-product on-farm utilization). If not, it was more profitable to invest in only energy recovery, as nutrient recovery by secondary solid-liquid separation or struvite precipitation with end-product sales were not as profitable. However, the absolutely largest increase in profitability lies within investing in a primary solid-liquid separation. As for the case farm, this investment reduced costs by more than 2 MSEK, while any of the latter scenarios reduce costs by 0,1-0,2 MSEK. Furthermore, the possible utilization of the waste heat from energy recovery increased profitability by a factor of ten.

Av samtliga globala processer som reglerar jordsystemet är de biogeokemiska flödena av kväve (N) och fosfor (P) mest påverkade av mänskliga aktiviteter. Inerta former av N och P omvandlas till reaktiva former som sprids i miljön, där de orsakar eutrofiering och påverkar marina ekosystem negativt. Majoriteten av de reaktiva N- och P-formerna används för framställningen av mineralgödsel. Ett alternativt sätt att producera gödsel är att återvinna näringsämnena i avloppet. En teknik som återvinner näringsämnen i urin är basisk urintorkning. Teknologin stabiliserar urea med ett basiskt torkningsmedium och koncentrerar näringsämnena genom att evaporera vattnet i urinen. Slutprodukten är ett torrt gödsel i pulverform. I det här projektet testades urintorkningsteknologin för första gången i ett fältförsök. Ett system för urintorkning med kapacitet att förånga 40 kg urin dygn-1 m-2 konstruerades och integrerades i ett befintligt torrt sanitetssystem för användning under en period på tre månader. I projektet utvärderades 13 dygn av de 3 månaderna. Resultaten visade att 24 kg urin tillfördes systemet och att systemet kunde upprätthålla en kontinuerlig torkning av urinen. Efter torkningen återvanns majoriteten (97 %) av N i slutprodukten. På grund av att den tillförda mängden urin var liten blev växtnäringshalterna i slutprodukten och i torrsubstansen (TS) av slutprodukten låga. Systemet hade emellertid potential att torka mycket större kvantiteter urin. Om systemets fulla potential hade använts, det vill säga att torka 40 kg urin dygn-1 m-2, så hade särskilt N- och P-halterna ökat avsevärt. N-halterna hade även ökat ytterligare om torkningen hade utförts vid en lägre temperatur. Systemets energiförbrukning var hög, eftersom systemet hade en kontinuerlig energikonsumtion och även komponenter med hög effekt. I jämförelse med den konventionella avloppsvattenreningen och produktionen av mineralgödsel har systemet en hög energikonsumtion, men i jämförelse med en förbränningstoalett är systemets energiförbrukning likvärdig. För att minska energiförbrukningen kunde reglertekniska åtgärder utföras så att systemets energitillförsel upphör när systemet inte används. Systemets energiförbrukning får även ställas i relation till de problem som dagens system för livsmedelsproduktion och sanitet medför. Till skillnad från nämnda system möjliggör urintorkningsteknologin besparing av dricksvattenresurser, ett slutet kretslopp av näringsämnen och en minskad påverkan på miljön. / Of all global processes that regulate the earth system, the biogeochemical flows ofnitrogen (N) and phosphorus (P) are the most affected by human activities. Inert forms of N and P are converted into reactive forms that are dispersed in the environment, causing eutrophication and affecting marine ecosystems. The majority of the reactive N and P are used for the production of mineral fertilizers. An alternative way of producing fertilizers is to recycle nutrients from waste water. A technology that reuses nutrients in urine is alkaline urine drying. The technology stabilizes urea with an alkaline drying medium and concentrates the nutrients by evaporating the water in urine. The end-product is a dry fertilizer in powder form. In this master project, the alkaline urine drying technology was tested for the first time in field conditions. A system for urine drying with the capacity to evaporate 40 kg of urine day-1 m-2 was constructed and integrated into an existing dry sanitation system for use over a period of three months. The master project evaluated the system for 13 days of the 3 months. The results showed that 24 kg of urine was collected in the system, significantly less than what the system had been designed to dry. Furthermore, the results showed that the system functioned smoothly recovering 97 % of the urine-N in the end-product. The nutrient content in the end-product and the dry matter of the end-product was low due to the low amount of urine that was collected. However, the system had the potential to dry much larger quantities of urine. If the system would have been operated to function at full potential (drying 40 kg of urine day-1 m-2) the N- and P-content in the end-product would be much higher than that observed during the 13 days. Furthermore, the system if operated at lower temperatures has the potential to recover more N. The system’s energy consumption was high, as the system had a continuous energy consumption. In comparison with the conventional waste water treatment and the production of mineral fertilizers, the system has a high energy consumption, but compared to an incineration toilet, the system’s energy consumption is equivalent. In order to reduce the energy consumption, automatic control could be implemented so that the energy is switched off when the system is not used. The system’s energy consumption may also be set in relation to the problems that today’s systems for food production and sanitation entail. Unlike the aforementioned systems, the urine dehydration technology does not consume drinking water, it enables recycling of nutrients as well as a reduced impact on aquatic life.