Göteborg Energi has a surplus of district heating during spring, summer and fall. The heat surplus is due to a constant production of waste heat from oil refineries and heat from waste incineration over the year. It would be desirable to increase the demand for heat and the uptime for the newly built combined heat and power generation plant, Rya Kraftvärmeverk. One alternative could be to integrate Rya Kraftvärmeverk with a pellet production facility. By producing heat, electricity and pellet in a joint process the energy use can be decreased.

Phosphorus is essential to all plants and is taken up from the soil as the ion H2PO4 - (and to some extent HPO42-). Plant availability depends on, among other factors, the soil pH. In order to provide for plant available phosphorus, it is applied as mineral fertilizers and farmyard manure. However, that causes phosphorus leaching from arable land to surrounding surface waters and lakes and contributes to the eutrofication. There are three types of soils in Sweden that are at higher risk of contributing to phosphorus leakage.

Denna uppsats är skriven höstterminen 1997, då ett nytt läromedel började utvärderas i Linköping. Den svenska skolan har sedan en tid haft bristande natur- och teknikundervisning i de lägre årskurserna. Den Kungliga Vetenskapsakademien gav vissa av Linköpings skolor uppdraget att i lärarlag arbeta med ett nytt material, för att kunna se dess fördelar och brister. Materialet heter Science and Technology for Children (STC) och är framtaget av den amerikanska organisationen National Science Resource Center. Sedan utvärderingen av STC har läromedlet bytt namn till NTA (Natur och Teknik för Alla).

Emissions of radionuclides to the atmosphere can lead to wet deposition on plants in the event of rainfall. An increased level of radioactivity in the plants may occur due to interception and retention of the radionuclides. If the content of the plants is above the threshold limit value, entire yields may have to be destroyed. In order to prevent contamination or decrease the content countermeasures can be taken. The impact of the biomass, leaf area index (LAI) and growth stage of the plant on the interception and retention is important to know in order to decide which countermeasures to use. Weather may also be an important factor. In this work the interception and retention of 134Cs and 85Sr by spring wheat, ley and spring oil-seed rape was studied.

This is a project about how you grow timothy seed and red clover seed successfully. The main part is about economic analyse to see if it is any economy by growing leyseed. There are lots of things to be aware of to get all the costs in your economic analyze. Timothy Timothy seed is planted on 4400 hectares in Sweden. It is possible to grow timothy seed in the south part of Sweden. Timothy is very sensitive for dry weather in spring and in the beginning to summer. Timothy gives acceptable harvest of seed for about three years. Red clover Red clover is also sensitive for dry weather and is suitable to grow in the south part of Sweden.

Emissions of radionuclides to the atmosphere can lead to wet deposition on plants in theevent of rainfall. An increased level of radioactivity in the plants may occur due tointerception and retention of the radionuclides. If the content of the plants is above thethreshold limit value, entire yields may have to be destroyed. In order to preventcontamination or decrease the content countermeasures can be taken. The impact of thebiomass, leaf area index (LAI) and growth stage of the plant on the interception andretention is important to know in order to decide which countermeasures to use.Weather may also be an important factor.In this work the interception and retention of 134Cs and 85Sr by spring wheat, ley andspring oil-seed rape was studied.

It is estimated that 22 000 contaminated areas exist in Sweden today. In order to classify the risk of contaminant migration from these areas and to prioritize which of these contaminated areas should first be treated, the Swedish Environmental Protection Agency (EPA) has designed a method, for the investigation of contaminated areas (MIFO). One of these contaminated areas is the landfill Gräsötippen outside Köping. The landfill has been used by both Yara AB and the Köping municipality between the years 1945 and 1975, and both industrial and household waste have been deposited there. The aim of this report is to survey which contaminants that can be found in the soil and water in the landfill Gräsötippen and to evaluate the migration of these contaminants.

Metan är en stark växthusgas som är viktig att ta med i beräkningarna när det gäller klimatförändringar. Feedback från myrmarker vid en ökad temperatur i samband med klimatförändringar har diskuterats, bland annat eftersom myrmarker är en källa för metan till atmosfären. Det finns många faktorer som påverkar metanemission, och en av dom är vegetation. Olika sorts vegetation tros bidra olika mycket till avgivningen av metan. Syftet med denna studie var att undersöka hur stor betydelse det har att ta med olika växtsamhällens sammansättning i beräkningarna för att uppnå korrekta uppskattningar av metanemission från myrmark på ekosystemnivå.

During whole-tree harvesting, there is a risk that the soil will become impoverished of nutrients. To prevent this, nutrients are returned to the harvested site as wood ash. This action also reduces the risk of soil acidification. Nevertheless, the ash does not result in any increase of tree growth if it is added on mineral soils, which is where the measure is most commonly used in Sweden. Due to the lack of growth response, the interest from landowners is small, which is why ash amendment today is not done enough to compensate for the need.

Green manuring is a way of creating an organic fertilizer by growing a crop that is mowed down. Besides the fertilizing effect this method has been shown to have a positive influ-ence on soil organic matter as well as weed flora, and green manure is an important me-thod of weed control in organic farming in parts of Sweden. However, the release of nu-trients from the green manure varies and can therefore be difficult to control. Risks for losses of nutrients are also present. Although the area of organic farmland is increasing in Sweden, the use of green manure is decreasing.This report contains a literature study which compiles research on the functions of green manure in a cropping system and also how the crop can be used if harvested, for example to produce biogas.

Hemp is an ancient cultivated plant that came to Sweden in the 1st to 2nd Century and was particularly interesting for use for food, clothing and building materials. Over time, other applications have been developed for hemp, e.g. in energy and health products. Interesting new uses for hemp continue to be identified and this fascinating plant has incredibly versatile applications.In this project, seed production of industrial hemp in Sweden was studied and evaluated. Five different methods are described, four of which are proven under Swedish conditions.

Underdrainage is a costly investment but often a necessity to maintain rationalized plant cultivation, one can also see underdrainage as insurance to successful plant cultivation. Late ripening crops, low yield and difficult tillage cultivation are examples on an insufficient drainage. (Kvarnemo 1983) A drained field rise in land price and the scheme of the tiled drains is seen as a value item. The interest for underdrainage among the farmers follows with shifting economic situations within agriculture and has for long time been low. A big part of the Swedish tiled drainage systems is since 1930 and ahead. Many of these tiled drainage systems need to be replaced or complemented. The life length of one tiled drainage system varies with maintenance but can still remain in good function after 75 years with correct management.

The common warthog (Phachocoerus africanus) is a relatively long-legged pig with noticeable curved tusks, a short neck and three pairs of facial warts. It has four recognized subspecies. The common warthog is a non-migratory ungulate living on the African savannah. It is a hindgut fermenter and predominantly dependent on high-quality foods. It prefers open areas for grazing but use bushes for cover.

Green manuring is a way of creating an organic fertilizer by growing a crop that is mowed down. Besides the fertilizing effect this method has been shown to have a positive influ-ence on soil organic matter as well as weed flora, and green manure is an important me-thod of weed control in organic farming in parts of Sweden. However, the release of nu-trients from the green manure varies and can therefore be difficult to control. Risks for losses of nutrients are also present. Although the area of organic farmland is increasing in Sweden, the use of green manure is decreasing.This report contains a literature study which compiles research on the functions of green manure in a cropping system and also how the crop can be used if harvested, for example to produce biogas.

The purpose of this master thesis was to study the water system for mechanically cleaned water at Skärblacka mill, in order to find and evaluate possibilities of using energy more efficiently. The thesis also includes an evaluation of the software tool ?Pumpanalys?Skärblacka mill produces pulp and paper. The large amount of water required is cleaned mechanically through filters and called mechanically cleaned water (MR0). The MR0 water is pumped out to the factory by four crude water pumps.