Biogas is a renewable energy produced through anaerobic digestion, which means that organic matter is degraded by microorganisms under anaerobic conditions. The produced biogas can then be used for cogeneration, electricity, heat or upgraded to vehicle gas. Eskilstuna Energy & Environment AB has four digesters at Ekeby water sewage treatment plant, Eskilstuna. One of the biogas reactor (RK4) is equipped with a jet-mixing system while the remaining digester uses top-mixing. The mixing system is an important parameter to achieve optimum operating conditions for the process regarding gas production and degree of digestion.

Russian comfrey, Symphytum x uplandicum, was tested as a plant nutrient source in a trial with tomatoes. Comfrey liquid was produced by Stiftelsen Holma i Höör. Tomato plants of the cultivar Aromata planted in a medium of soil:peat (1:1) enriched with organic nutrients and lime, were fed with comfrey liquid plus Biofer, in three different concentrations. Two different concentrations of BioRika were used as comparison, along with an unfertilized control group. In the comfrey treatment I a total amont of 1g N, 0,23 g P, 0,84 g K, was given to the tomatoes.

På SSAB EMEA i Luleå tillverkas stål baserat på pellets från LKAB i Malmberget och i mindre utsträckning LKAB i Kiruna. I framtiden ändras förhållandet och Kiruna blir den större leverantören. Pellets från Kiruna skiljer sig från motsvarigheten i Malmberget genom en högre fosforhalt, även kolpulver och koks som används vid nedsmältning av pellets kommer att ha en högre fosforhalt. Detta kommer att leda till en stigande fosforhalt i råjärn vilket i sin tur medför ett försvårande av fosforreningen på SSAB. Verket har för närvarande ingen praxis för hantering av de ökade mängderna fosfor.

Sammanfattning Kisel (Si) är det näst vanligaste ämnet (drygt 25 %) i berggrunden. Bara en del av detta är tillgängligt som monokiselsyra, den form i vilken kisel är upptagbart för växter. Jordens kiselinnehåll är beroende av bergets vittring. Mycket höga halter av kisel återfinns i naturen i vulkaniska substrat (pimpsten innehåller drygt 66 % Si och scoria närmare 47 % Si), i diatomit (ett mineral bestående av resterna från encelliga kiselhaltiga alger, s.k. diatoméer) innehållande 66 % Si, scoria approximatly 47% Si), in diatomite (a mineral consisting of the remainings of single celled algae, diatoms containing < 40 % Si) and in some clays (30-60% Si).

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.

To achieve the requirements to decrease emissions of greenhouse gases by 20 % by 2020, Swedenneeds to increase its use of bioenergy. In doing so it seems natural that those who already haveaccess to large amounts of biofuels in the form of by-products such as straw, wood chips anddigestible materials take advantage of these assets locally. By combining production of heat withpower production at the farm it may be possible to not only reduce the direct use of fossil fuel forheating but also reduce energy costs.The purpose was to simulate different cases of using a small scale biofueled combined heat andpower plant for farm-based systems. A MatLab-model was developed and used to draw conclusionsabout the costs for production of heat and electricity with different conversion technologies.The model uses climate data to simulate the variations in heat energy demand on a day-to-day basis.The given heat demand is the base of the simulation and from this the possible electric output iscalculated. This study has focused on the impact of the following properties: electric-, heat- andtotal efficiency, fuel, fuel price and specific fuel requirements.

A common perception is that fungicide treatments increases yield, but that the nitrogen of the particular grain is diluted so that the overall removal of grain nitrogen from the field remains unchanged. The aim of this paper is to demonstrate that a healthy crop reduces the risk of nutrient loss from agricultural land. The results from genotype and plant protection trials often show constant nitrogen content in the grain, although the yield has been increased. Results from such experiments are therefore processed in order to confirm this and show that it is no statistically significant difference between the protein content (and also nitrogen content) in crops which have undergone fungicide treatment compared to crops which remained untreated. The trials processed have been carried out in the southernmost part of Sweden and are distinguished to concern winter wheat production.The explanation to the results is that a healthy crop is able to maintain the biological functions of the plant in a more efficient way than a crop damaged by a fungal infection.

In this thesis, three separate experiments have been performed on different aspects of the interaction between the causal agent of clubroot, Plasmodiophora brassicae, and its hosts. In the first experiment the pathotype of the P. brassicae single spore isolate, which is currently used to construct a reference genome, has been classified using the ECD bioassay. The disease severity of infected plants was scored according to two different scales and the pathotype was determined according to three previously published guidelines. The results were compared to previous published studies describing the e3 isolate. The life cycle of P. brassicae is not well understood.

The purpose of this study has been to evaluate whether a Low temperature bio-mass dryer could be integrated with the local district heating system in Malå. The aim is to increase the thermal efficiency of the cogeneration plant in Malå, by lowering the temperature of the cooling medium. Another benefit that comes from this is improved combustion efficiency at the power plant, since drying the fuel causes an Increase of the heating value.Simulations has been made in Excel, and with use of linear regression, to find out if it is profitable. Data for this purpose has been supplied by the power company Skellefteåkraft and furthermore SMHI.The result of the Calculations shows that a very efficient bio-mass dryer is needed, if yield of investments should be made possible. An Investment of 4,27 Mkr, in a dryer, could at a such criterium return 60000 kr/year, if the price of the biomass is 190kr/MWh.

Eutrophication of the Baltic Sea and Swedish lakes remains a major problem despite many years of effort to reduce the emissions of nutrients. One major source is waste water systems, especially private sewage systems. These sewages accounts for a very large share of nutrients per capita in comparison with citizens connected to larger sewage treatment plants. Norrtälje community has the greatest number of private sewage systems in Sweden. Discharges of nutrients, especially phosphorus, to the Baltic Sea from these sewage systems are significant.

The purpose of this report is to study the risk of dust explosions at the candy manufacturing plant Leaf Sverige in Gävle, Sweden. The risk analysis was conducted with a preliminary hazard analysis, PHA and event trees. The analysis focuses only on the risk posed to employees and material damages at the plant. No third person injuries have been considered. Another purpose of this report is to study risk awareness and risk communication concerning dust explosions.

Nanofiltration is a proper way of preparation of drinking water. The process has a lot in common with reverse osmosis where a semipermeable membrane is used to separate a pure water flow from the remaining water. A pilot plant was used to ensure that nanofiltration is a suitable technology for a specific waterworks station in Glemmingebro, Ystad. The purpose was also to find out if a pH-adjustment is needed for feed water in a possible full scale plant.  In this case nanofiltration is used mainly to remove sulphate and calcium since the raw water contains concentrations of these substances which exceed the limits for potable water. It is important to receive a high recovery (RC), otherwise the deliviery of water won?t be high enough.

The use of combi-drilling during spring tillage has become very common in southern Sweden in recent years. Combi-drilling leads to fewer passes on the field and better plant nutrient utilisation. An example of a combi-drill is the Väderstad Rapid, which is very widely used in spring tillage in southern Sweden. The Rapid has separate fertiliser and seed coulters, which means that the draught requirement is relatively high. It thus requires large, heavy tractors, which compact the soil and are comparatively expensive to buy and run. A few years ago the Finnish combi-drill Tume Nova Combi came onto the Swedish market.

At Forsmark nuclear power plant a new course called "education in everyday safety" has been started in an attempt to improve the safety culture. The goal is to spread the of expectations and approach the maintenance management has set, to all employees working at the plants. During the course, theory is mixed with practical tasks to reach a common view how work should be done to achieve safety for the plant and the people that work there.The practical tasks are done inside "maintenance simulators". They are built inside 20 ft containers which contains two dummy pipe systems. On the pipe systems some valves, a flow meter and a pump has been installed.

This diploma work covers an investigation over the heat - and hot water systems of thetenant-owner's association, Bogården. The heat - and hot water needs of Bogården aresatisfied by both district heating as well as three heat pumps. Implemented investigationshows that the heat pumps are not used in a profitable way. Apart from that, the reservepossibilities are small. There is also a risk of the growth of Legionella bacterium in thehot water system.Since the heat pumps are already installed, HSB-Gävleborg (responsible for Bogården)has a wish to investigate possible proposed actions for optimization of existing plant.After completed investigation, a new proposed action is presented.