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295 Uppsatser om Nitrogen retention - Sida 1 av 20

Våtmarker för näringsretention i Lillån : var bör de ligga och vilken effekt kan vi förvänta

Construction of wetlands in the agricultural landscape may reduce nitrogen and phosphorus transfer to streams, thereby reducing the eutrophication of lakes and seas. The agriculturalstream Lillån, a tributary to stream Sagån, ends up in Lake Mälaren and is transporting large amounts of these plant nutrients. The aim of this study was to estimate how hypothetical wetlands of different size and location may reduce nitrogen and phosphorus load from stream Lillån. Estimated nutrient retention in several small wetlands was compared to retention in a single large wetland based on existing data from the agricultural stream and from a nearby smaller stream. Retention in the stream was suggested to decrease along with the nutrient concentration in the water.

Förslag till kväverening i Forsåsystemet genom våtmarksetablering

The last hundred years humans have drastically changed the amount of available nitrogen in nature. Today human activities release twice as much available nitrogen as all natural processes are doing together. We also have degraded nature´s possibilities to take care of nitrogen through the draining of wetlands and straightening of rivers. In order to regain the potential of Nitrogen retention in the water systems there now requires a reshape of the landscape we live in. A planned expansion of the mining activities in Garpenberg, Dalarna, would double the content of nitrogen in the waters below the mine.

Referensvåtmarker för uppföljning av växtnäringsretention i anlagda våtmarker

One of the environmental problems today in seas, lakes and streams is eutrophication. This is often caused by nutrients such as phosphorus (P) and nitrogen (N) that leak from agricultural areas. A measure to partly prevent the nutrient discharge is to construct or restore wetlands.In order to control the efficiency of nutrient reduction of existing wetlands in the county, the administrative board in Västra Götaland wants to find different criterias for reference wetlands. These reference wetlands should represent other wetlands and be used in future evaluations of reduction of nutrients and design of constructed wetlands. According to the administrative board in Västra Götaland the reference wetlands should have a catchment area of about 50 hectare consisting of at least 70 % arable land, to represent wetlands created to remove nutrients.

Translokation av större vattensalamander : -bevarandestrategi eller riskåtgärd?

This study evaluates the retention of nitrogen and phosphorus in four newly constructed wetlands in the municipality of Falkenberg, Sweden. The four wetlands have been selected because they have been specifically constructed with the aim to reduce nitrogen and phosphorus in farming areas. The process of selecting the specific wetlands has been done in collaboration with the county administration in Halland. Through field studies in collaboration with the landowners where the wetlands are sited, the areas that provide the wetlands with water were determined. The size of these drainage areas were determined in a GIS computer program. The type of land use within the drainage areas was also determined.

Näringsämnesretention i fyra nyanlagda våtmarker i Falkenbergs Kommun

This study evaluates the retention of nitrogen and phosphorus in four newly constructed wetlands in the municipality of Falkenberg, Sweden. The four wetlands have been selected because they have been specifically constructed with the aim to reduce nitrogen and phosphorus in farming areas. The process of selecting the specific wetlands has been done in collaboration with the county administration in Halland. Through field studies in collaboration with the landowners where the wetlands are sited, the areas that provide the wetlands with water were determined. The size of these drainage areas were determined in a GIS computer program. The type of land use within the drainage areas was also determined.

Småvatten då och nu : en förändringsstudie av småvatten i Skåne och deras kväveretentionsförmåga

Wetlands play an important role in the ecosystem. They reduce the impact of flow flux in the drainage area, acts as upholder of biodiversity, as an esthetic and recreational component in the landscape and they have the ability to reduce nutrients such as nitrogen, and help preventing eutrophication in costal areas.The number of wetlands in Scania have, due to the intensified agriculture been reduced to maximize the area suitable for crops.However since the mid 80th the consequences of this has been acknowledged, and many wetlands have been restored.This master?s thesis aim to see what impact this development have had on wetlands in Scania over the last 60 years. And also look at some of those factors important for the efficiency of nitrogen removal in wetlands. During the process a detailed manual for inventories of this sort was created.The material used to execute the inventory of wetlands where aerial photographs over Scania from the 1940th, 1980th and 2000.

Näringsretention i återskapad våtmark på betesmark : studier av en mad vid Bornsjön

It is important to construct or recreate different types of wetlands and study their retention of nutrients, since knowledge of their effectiveness in this matter is poor. In 2003 a wetland was constructed on an old meadow on the western shore of Lake Bornsjön in central Sweden. The main purpose of the wetland was to reduce the amount of phosphorus entering the lake, which is the back-up water supply for Stockholm when the city cannot obtain water from Lake Mälaren. Large areas around Lake Bornsjön consist of agricultural land and the nutrient concentrations in the inflows to the lake are usually relatively high (approx. 1 mg/l total nitrogen and 0.05-0.1 mg/l total phosphorus).

Effekten av uteblivna miljöersättningar för anläggning av våtmarker

Environmental subsidies are used as incitements to farmers for development of sustainable land use. In 2014, applications for funding constructed wetlands were not available. This paper examines the environmental consequences of this lack of funding in one intensively cultivated region Skåne län, southern Sweden.A review of wetland applications between year 2007-2013 show that the average rate of applications has been 31 projects per year with a wetland size of 4,48 ± 1,61ha per project (mean±95% CI). Based on interviews, the result suggests that the lack of funding in one year leads to between 102 and 140 ha of constructed wetlands that is not built. This correspond to a total loss of increased Nitrogen retention capacity between 6,0 and 91,7 tons/year and a loss of increased phosphorus retention capacity between 0,17and 2,1 tons/year in the drainage basins of Skåne.Further the interviews show that continuity of environmental regulations and funding is important for the farmers? interest in environmental measures.It is concluded that the total loss of increased retention capacity is small compared to the annual transport of nitrogen and phosphorus in the drainage basins.

Modellstudie av föroreningsretention i Bäckaslövs våtmark : Tillämpning av modellverktygen MIKE SHE WET och MIKE 21

During the nineties, ecological handling of urban storm water became very popular in Sweden. Together with Chalmers University of Technology and two Swedish communities, DHI Water and Environment has been doing research of storm water ponds and constructed wetlands. This thesis work is a part of that research project. The work has been applied at the Bäckaslöv storm water treatment plant in Växjö, Sweden. The plant consists of one storm water pond and a downstream constructed wetland.

Näringsbelastning på en anlagd våtmark från åker, skog och enskilda avlopp :

This work is a part of the project ?Våtmarker i odlingslandskapet ? uppföljning av miljömålen? (Wetlands in arable land ? following-up of the environmental goals). The main objective with this project is to study nitrogen and phosphorus retention in a constructed wetland by using mass balance calculations. Continuous measurements of nutrients and water flow through the inlet and the outlet of the wetland are made. However, substantial amounts of nitrogen and phosphorus were assumed to reach the wetland with a drain-pipe transporting wastewater from nearby houses (10 persons).

Grundvattensänkning till följd av järnvägstunnel genom Hallandsås : miljökonsekvenser relaterade till förändrad kväveomsättning i mark

This thesis was carried out to give some background information to a report of SLU (Swedish University of Agricultural Sciences) for the Swedish National Rail Administration (Banverket). The requested information was to provide basic data for an environmental impact assessment of the construction of the tunnel through Hallandsås. The aim with the thesis work was to discuss and quantify the leaching of nitrate and the emission of nitrous oxide from the soil at the groundwater level established through the tunnel project. The nitrogen related processes that could be affected were described and discussed. The different areas where a decreased groundwater level can cause changes in the nitrogen processes are the wet and moist areas.

Förstudie till våtmark i Rimbo : Design för optimal hydrologi och kväverening

The euthropthication of the Baltic Sea is a threat that is beginning to be taken seriously by the governments concerned. In Sweden, regulations concerning the allowed nitrogen (N) concentration in the effluent water from wastewater treatment plants are being tightened up. The Rimbo wastewater treatment plant has been imposed to reduce the annual mean concentration of total N in the effluent water to levels below 15 mg l-1. A more and more common way to reduce the nitrogen level in wastewater is to let the water pass through a wetland. This study investigates the possibility to build this kind of wetland at the outlet of the Rimbo wastewater treatment plant.A prestudy of the topography, soil characteristics and groundwater flow indicates that the land area in question is well suited for the construction of a wetland.

Combining the Concepts of Fear Aroual and Customer Satisfaction & Retention - An Ethnographic Case Study on Krav Maga

The purpose behind this study is to explore and explain the role of fear arousal when combined with the concept of customer satisfaction and retention in one marketing strategy. The major theories applied are the concept of fear appeals and the concept of customer satisfaction & customer retention. We chose to conduct our research through an ethnographic case study of KM. We did a qualitative study where we collected 10 interviews and we conducted observations. Our empirical data consists of academic articles from scientific journals, interviews andobservations.

En studie av retentionen i floden Oder och dess avrinningsområden, Polen.

Nutrient enrichment is the main cause of the increasing eutrophication process in the Baltic Sea during last century. A prerequisite counteract this process the load of nutrients to the Sea must be investigated. The large contribution of nutrients to the Sea is caused by emission from the rivers within the drainage basin. For the total emission of nutrient into the Sea the retention process in the rivers has big influence. This process in the river system has been assumed as a not important part of the nutrient cycle.

Modellerade och uppmätta kväveflöden i energiskog som bevattnas med avloppsvatten

The aim of this essay was to study the nitrogen flow in two willowplantations, at different locations in the south of Sweden, that wereirrigated with sewage. The study was also performed to compare thedifferences in nitrogen flows between two years, 1998 and 1999. The studywas made in three parts. First, the denitrification activity was measuredusing the acetylen inhibition method. Second the nitrogen flow, as well asthe water- and heat flows, were modeled through the SOIL-SOILN-modelThird; the nitrogen flow was calculated to compare with the results fromthe model.The results from the measurements were then compared with the resultsfrom the SOILN-simulations to detect differences in the denitrificationrate.

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