Perfluorinated substances (PF) are environmental pollutants that are used to coat fibres of so called ?all weather clothes? to make them water resistant. PF are effectively spread through water. Waste water treatment plants (WWTPs) are a pollutant source of these substances. PF are poisonous to different kinds of organisms, and supposedly also to human beings, if concentrations are sufficiently high.Perfluorinated substances have been investigated at three waste water treatment plants in Stockholm during the 2000?s.

Society has depended on fossil-based fuel for a long time, which has led to a fundamental increase of greenhouse gases in the Earth?s atmosphere. To tackle this problem the international community has agreed that action is necessary. Focus is now directed towards local extraction of energy from renewable sources such as biogas.Utö is participating in the Green Island project, which aims to investigate the possibility of making the island climate neutral. This report has been implemented on behalf of Skärgårdsstiftelsen, the main partner responsible for the Green Island project in Sweden.

Sewage sludge contains plant nutrients and has earlier been utilised as fertilizer to cropland. Unfortunately not only plant nutrients but also heavy metals, pathogens and organic contaminants tend to accumulate in sludge. The suitability to use sewage sludge in agriculture has therefore been subject to several discussions over the years. The Swedish food industry does no longer accept sludge as fertiliser for Swedish producers. In 1999 the Swedish parliament accepted several objectives for environmental protection. In order to prevent environmental pollution and further exploitation of the earth crust, one of these objectives confirm that phosphorous from sewage shall be recirculated to arable land.

Chemical substances are spread diffusely and uncontrollably as a result of the increased consumption of goods. REVAQ is a certification system that works to reduce the flow of hazardous substances to Swedish treatment plants and to create a sustainable nutrient recycling. According to REVAQ, the yearly accumulating rate of metals should not exceed 0.2% in soil per year. Silver and bismuth are two metals that do not fulfill this requirement. The silver concentration in sludge decreased during the last decade, however the last few years, it has leveled off.

Because of the increasing trends in energy consumption and increased environmental awareness, greater focus has been placed on improvement and development of renewable energy sources. An already proven and accepted method is biogas production from anaerobic digestion at municipal wastewater treatment plants.In the waste water treatment process solid material and dissolved pollutants are separated from the water, forming a sludge. The sludge is separated from the process and stabilized during anaerobic digestion or aerobic aeration. Most often, mesophilic anaerobic digestion is used. Because of degradation by microorganisms, biogas with a high content of methane is formed during the digestion.

In connection with Henriksdals wastewater treatment plant (WWTP) a smaller plant is situated called Sjöstadsverket where new methods for wastewater treatment are tested and evaluated in different process lines. On one of the lines experiments with enhanced biological phosphorous removal (EBPR), have been carried out to evaluate if it is a good alternative to traditional chemical phosphorus removal. This thesis evaluates the results from the experiments conducted during fall 2005.The incoming water from Hammarby Sjöstad consists of only household wastewater, which gives a wastewater with high concentrations of nutrients and organic carbon. This is partly positive, because one of the limiting factors for effective biological phosphorus removal is the lack of easily biodegradable organic carbon. The high concentrations of ammonium and phosphorus demand a high reduction to achieve the requirements of outgoing concentration.To optimize the process experiments with different recirculations and different aeration techniques have been made.

The aim of this study was to in laboratory experiments investigate how addition of urea, ECOX and structural materials can optimize sanitization during composting of sewage sludge. Today we strive for a sustainable society and the importance of closing the nutrient loop increases. It has therefore become even more important to safely reuse plant nutrients from human excreta to agricultural land. Partly because it increases the sustainability of society as the world's supply of many nutrients are finite, partly because it promotes human health, both by reducing disease transmission and by increasing Agricultural production. An untapped resource such as sewage sludge that is rich in nutrients and humus-forming materials could replace parts of the commercial fertilizers used in Sweden today. owever, sewage sludge contains undesirable substances such as heavy metals and drug residues, and pathogenic microorganisms.

Chemical substances are spread diffusely and uncontrollably as a result of the increased consumption of goods. REVAQ is a certification system that works to reduce the flow of hazardous substances to Swedish treatment plants and to create a sustainable nutrient recycling. According to REVAQ, the yearly accumulating rate of metals should not exceed 0.2% in soil per year. Silver and bismuth are two metals that do not fulfill this requirement. The silver concentration in sludge decreased during the last decade, however the last few years, it has leveled off.

An efficient market implies that the use of fundamental analysis should not result in excess return, and that any return exceeding the market average can be explained by compensation for risk, accord-ing to The Capital Asset Pricing Model (CAPM). The focus of this study is to test whether the suc-cessful investment strategy developed by Piotroski (2000) generates excess return on American data, after risk adjustment by using Fama & French?s (1993) 3-factor and Carhart?s (1997) 4-factor CAPM. Initially we form stock portfolios based on companies characterized by high book-to-market values, additionally, we divide them into different performance classes by ranking them with Piotroski?s (2000) measure of financial performance, F_SCORE.

This study aims to measure the effect of accounting conservatism and to identify thebusiness activities causing firms to undervalue owners? equity. To estimateaccounting conservatism, we have followed the hypothesis that no firm over time cangenerate a return greater than its cost of equity, i.e. CAPM. Thus, if a firm in factgenerates an excess return over time, we assume that the excess return is an estimateof accounting conservatism within that firm.The hypothesis originates from the corporate valuation model ?Economic ValueAdded®? which tries to adjust for accounting bias.

Bringing back the nutrients from the city to the country is becoming increasingly important, as the world?s stores of nutrients get more exhausted. Sewage sludge is an unapplied resource, rich in plant nutrients, which could replace parts of the commercial fertilizers used in Sweden today. Sewage sludge may contain large amounts of pathogens, such as Campylobacter and Salmonella, why use can cause severe spreading of infections, both to animals and humans. These pathogens have the ability to survive for a long time in soil and water and therefore some sort of treatment of the sludge is recommended before use.

This study is based on a statistical analysis of fundamental key ratios on the Stockholm Stock Exchange during the period 2004-2012. In total 35 financial ratios of 90 companies were tested, ultimately five ratios remained within the 5% significance level. These ratios were ROA, P/B, Total Yield, EV/EBIT and Operating Margin. A custom made investment model was created based on the purpose to achieve a risk-adjusted excess return. The results in general did not show any significant difference in return between the model's portfolio and index.

Purpose: The purpose of this thesis is to examine whether some periods of declines in Swedish real credit can be explained by a credit crunch. Is it further possible, with these results, to do any conclusions about the banks behaviour in the on going financial crisis that has shadowed the country since 2007/2008? Method: A credit crunch is here defined as a period of supply-side restrictions on loans which doesn?t reflect the ongoing interest rates. By estimating a supply and demand function with a disequilibrium model the excess demand- and supply for credit due to different periods can be calculated. Conclusion: A credit crunch has been present during a period after the banking crisis of early 1990?s.

The purpose of this study has been to make an inventory of combustible waste in the region around Norrköping and to investigate the composition of domestic waste, industrial waste and two different types of sludge. The work was performed at the request of Norrköping Miljö & Energi, due to the planning of an incineration plant. The inventory of the waste was performed through inspection of environmental impact reports, from waste disposal plants in a number of local government areas in the region. The quantities were also compared to another inventory, carried out in a different way. The characterisation of the wastes was compared to the fuel specification determined by Norrköping Miljö & Energi.

In line with Sloan (1996) but on European data (STOXX 600) we are investigating whether stock prices reflect information about future earnings contained in the accrual and cash flow components. The extent to which current earnings performance persists into the future earnings performance is shown to depend on the relative magnitudes of the cash and accrual components of current earnings. Moreover, we still find a significant positive excess return (Jensen?s alpha and size-adjusted return) by replicating Sloans (1996) hedge portfolio by taking a long position in the stock of firms reporting relatively low levels of accruals and a short position in the stock of firms reporting relatively high levels of accruals. However, we find no evidence of negative excess returns for companies with relatively high accruals, this somewhat lower the total excess returns for all the portfolios.