The most common way to treat wastewater in Sweden today is by a combination of an activated sludge process and a chemical treatment. These processes are not very energy efficient and may not be the most environmentally friendly. That is why it is interesting to evaluate new alternative methods to see if they can be less harmful to the environment and help to a lower resource consumption. New techniques are tested in a pilot installation at Hammarby Sjöstad, Sjöstadsverket. To be able to evaluate these techniques in a wide perspective system analyses are conducted where different impacts can be considered, advantages and disadvantages in the systems.Five system structures for water treatment have been constructed in Matlab/Simulink in this study.

Obesity is the most common nutritional disorder, and is defined as an accumulation of excessive amounts of adipose tissue in the body. Obesity is a condition where an animal exceeds its optimum body weight by more than 10-25%. Risk factors associated with obesity may include breed, age, castration or high energy intake relative to energy consumption. The consequences of obesity are believed to be metabolic and hormonal changes, as well as cardiovascular and respiratory diseases, orthopedic problems, tumors and premature death. Prevention and early detection of obesity leads to better health care.

Uppgiften för examensarbetet har varit att göra en bestämning av ammoniumhalten ibiogasslurry med hjälp av jonkromatografi. Resultatet från analysen har sedan jämförtsstatistiskt för att bland annat se repeterbarheten för metoden. Metoden har även jämförts medden spektrofotometriska metoden som finns på Sobacken, så kallad Langemetoden.Ammoniumhalten är en parameter som påverkar biogasbildningen i rötkammaren och det ärdärför viktigt att denna hålls låg.Jonkromatografi är en separtionsmetod som bygger på jonbyteskromatografi. En separationsker i en kolonn innehållande en stationär fas och genom den flödar den mobila fasen ochäven provet. Den stationära fasen och eleuenten har olika laddningar, för katjonkolonnen ärden stationära fasen negativ och den mobila positiv.

In the production of pulp, paper and cardboard, a large amount of water is used daily. The water has to be purified in the internal purifying plant before it reaches the receiving body of water. In the biological purifying stage at the Stora Enso Skoghall mill, an aerated basin is used where the microorganisms, using oxygen, oxidize the organic material to carbon dioxide. The air is pumped from the bottom of the basin and the oxygen can then be transported from the air bubbles to the water through diffusion. The problem with aeration of waste water from the forest industry is that wood residues, such as fatty acids, are making the transport of oxygen in water more difficult.

Eutrophication is an environmental problem that affects more than ten percent of Swedish lakes. Excess nutrients increase the growth of algae, and cause major problems in the ecosystem through oxygen-free bottoms, fish kills, and at worst dead bottoms. Agriculture accounts for 44% of human emissions of phosphorus to lakes and rivers. Leaching occurs of particle bound phosphorus and of dissolved phosphate. The amount of phosphate in the soil solution that may be leached is partly due to the prevailing pH in the soil solution. The purpose of this study was to investigate how the relationship between phosphate solubility and pH was affected by liming.

Avloppsreningsverk står inför uppgiften att rena inkommande vatten för att möta lagstiftade gränsvärden till en så låg kostnad som möjligt. Att syresätta biologiska reningsprocesser är kostsamt eftersom luftningsanordningen förbrukar mycket energi. Ungefär en femtedel av Himmerfjärdsverkets totala elenergiförbrukning går till luftning av biologiska processer.För att öka Himmerfjärdsverkets energieffektivitet startades under 2010 experiment med olika strategier för luftflödesstyrning. En av verkets nitrifikationsbassänger byggdes då om för att möjliggöra zonvis reglering av syrehalten.Syftet med denna studie var att utvärdera reglering med ammoniumåterkoppling och syrehaltsprofil för styrning av Himmerfjärdsverkets nitrifikationsprocess. Utvärderingen baserades på reningsresultat och energiförbrukning.Med nuvarande reglerstrategi varieras luftningen genom återkoppling från syrehalten i den andra av sex zoner i varje luftad bassäng.

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.

This master thesis in energy optimization was made during the autumn of 2006 at Käppala wastewater treatment plant in Lidingö, Stockholm. A preceding thesis, where all electricity consumption was mapped, showed that the aeration in the biological treatment is the single largest consumer in the plant, and it is therefore of interest to reduce this cost. The oxygen control strategy used at Käppala WWTP is working well from a nutrient removal point of view, but not from an economic one. The last aerobic zones have a very low oxygen consumption during low loading periods which give rise to enhanced dissolved oxygen concentrations with excessive costs and reduced denitrification as a result. But also during periods of normal loading unnecessary high oxygen concentration are sometimes given.By modifying the aeration control strategy three full-scale experiments have been made, with the intention to reduce the air consumption.

In this thesis, the flows of reactive nitrogen (Nr) in Scania were investigated and quantified. The thesis was also intended to form a basis for comparison between the urban nitrogen flow and other flows of nitrogen within Scania. The management of nitrogen in society has disturbed the natural nitrogen cycle. This is linked to a series of environmental problems such as eutrophication, acidification, global warming and smog. The method used was Substance Flow Analysis (SFA) for Nr. For calculation and flow charts Scania was divided into three subsystems; air, water and society.

Bakgrund: Det har tidigare konstaterats att det existerar ett samband mellan aktiers likviditet och dess avkastning. Bevis för detta har främst gått att finna på utländska aktiemarknader. På den svenska aktiemarknaden har tidigare utförda studier konstaterat att detta samband inte existerar. Vi vill därför göra en studie på den svenska aktiemarknaden, vilken delvis innefattar en ny tidsperiod för att se om någon likviditetspremie existerar.Syfte: Vårt syfte med denna studie var att undersöka om det är möjligt att uppnå en högre avkastning genom att investera i en portfölj med relativt sett illikvida aktier jämfört med en portfölj bestående av likvida aktier på Stockholmsbörsen samt undersöka om faktorerna likviditet, betavärde samt företagsstorlek signifikant påverkar portföljernas eventuella överavkastning jämfört mot ett lämpligt index.Metod: Vi har skapat tre olika portföljer, med tio aktier i varje vilka representerar de minst, mitterst och mest likvida aktierna enligt vårt valda likviditetsmått, aktieomsättningshastighet. Likviditetsmåttet laggar en månad för att kunna användas som investeringsstrategi.

In the pilot plant at Hammarby Sjöstad, Sjöstadsverket, several new methods are tested in order to achieve a good use of resources. When a new technique is considered it is often the performance of the technique itself, under given conditions, that is evaluated. However, in order to evaluate the overall function the whole picture is needed. With a system analysis it becomes possible to make a comparison where all the positive aspects are put up against the negative ones, for the technique itself as well as its requirements. In this way the influence that minor components have on an entire system can be considered.This report presents a system analysis of an anaerobic membrane reactor (MBR) with a VSEP-membrane (Vibratory Shear Enhanced Process).

The purpose with this literature study was to investigate the possibilities for improvement of forage protein in dairy cows with focus on feeding strategies and conservation of forage protein. The utilization of forage protein in dairy cows is often not that efficient as it could be. The feed crude protein consists of both true proteins and non protein nitrogen. The digestion of proteins in the rumen depends on the protein degradation rate and the ability of the microbes to synthesize microbial protein. The microbes need a balance between carbohydrates that provide them with energy and proteins that are degradable in the rumen.

The requirements for wastewater treatment plants (WWTP) are gradually increasing, partly because of higher incoming loads, which in turn require a more efficient treatment process. In parallel with environmental and economic goals there are also desires to lower energy consumption without compromising the wastewater treatment. Furthermore, there is a demand on WWTP´s to alter eutrophication in aquatic systems through better nitrogen and phosphorus removal. An increasing number of WWTP´s have acquired biological nitrogen and phos-phorus removal. A by-product of this type of biological treatment is the formation of nitrous oxide, which is a potent greenhouse gas.

The EU has had a special agreement with their former colonies in Africa, the Caribbean and the Pacific Islands, the ACP-countries, for almost 30 years. This has granted the ACPs with preferences on the Europen market, which have been excluded from other countries. The agreement is now beeing re-negotiated to make it more in terms with the rule of the WTO?s most favoured nation-principle. The new agreement will differ from the present one as it will be a mutual free trade agreement where the ACP countries will open their markets to the EU as much as the EU opens up it?s market to them.

Due to excess precipitation that cause runoff, all soils in Sweden naturally leaches nitrogen.High leaching from arable land is an environmental problem when the runoff reacheswaters. In the international agreement, Baltic Sea Action Plan, the aim is to reduce therunoff of nutrients. Sweden has agreed to reduce its load of e.g. nitrogen to the Baltic Sea.One of the proposed measures is an increased use of site-specific N-fertilization, which hasbeen shown to increase nitrogen use efficiency and therefore also reduce the nitrogen runoff.Either yields are increased with the same total amount of nitrogen, or the total quantityof nitrogen is reduced with preserved yield levels, which is profitable for the farmers.The dynamics of nitrogen leaching differs between top dressing applications above orbelow the economical optimum. There is a consensus about a difference in the dynamics,but not about its magnitude.