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221 Uppsatser om Nitrogen fixation - Sida 5 av 15

Närsaltsdosering till luftad damm : en åtgärd för ökad TOC-reduktion hos Skoghalls Bruk luftade damm

In the process of making carton boards into Skoghall Mill, are great quantities of water being contaminated. This water has to be treated before it is possible to release into the recipient, Kattfjorden. One of the contaminations that is important to extract from the wastewater, is organic carbon (measured as TOC-total organic carbon) because microbiological breakdown can lead to the bottom becomig free of oxygen.The wastewater treatment at Skoghall Mill is done through an external wastewater treatment that is located at the factory. The biological treatment (aerated lagoon) is a 140 000 m3 water pool with surface aerator, which is give oxygen to the water. In the lagoon live microorganisms who performs the biggest part of the TOC-reduction.One problem with the lagoon is that the treatment of TOC is considerably worse during wintertime than during summertime.

Kvickrotens reaktion på klippning och konkurrens i rajgräs- och vitklöverbestånd :

Couch grass (Elymus repens (L.) Gould) is a severe weed in Sweden, and since both the use of herbicides and cultivation should be decreased, it will become increasingly problematic to control couch. The present work is meant to, by literature studies and an experiment, give some answers to the question if cutting and competition can depress the growth of couch. The experiment was carried out in the growing season 2001 at Ultuna, Uppsala, in plastic boxes. The design was three-factorial randomised complete blocks. The factors were plant combination, nitrogen level and cutting strategy.

Möjligheter att förutsäga kvävegödslingsbehov i höstvete med Yara N-tester

The Yara N-Tester is a handheld chlorophyll meter which can be used in several different crops as an aid to determine if there is a need of complementary fertilization with nitrogen (N) or not. If the crop requires more N the N-Tester will recommend an amount in kg per ha. The possibility to assess the need of N depends on the strong relation that exists between chlorophyll- and N-concentration in the leaves of plants. In the multiannual trial series ?Nitrogen to winter wheat at different soil conditions? measurements with the N-Tester was carried out at flag leaf emergence (GS 37). In this work the result of measurements, the NTesters ability to estimate the need of N in winter wheat, will be presented for the years 2008-2011.

Vad orsakar höga ammoniumvärden i ensilage? :

High levels of ammonia in grass silage have been up for discussion by Swedish advisers. One reason is that it is more difficult for the rumen-microbes to utilise high levels of ammonia. A low level of ammonia is also good because if the cattle can use more of the protein in the silage, they don?t need so much protein concentrate. That is very good for the economy at the farm, and it is also good for the environmental problems caused by high levels of ammonia. In this project, 24 samples of silage have been taken at 20 different farms in the south west of Sweden.

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.

Proveniensbestämning av vikingatida hornmaterial : En studie utifrån stabila isotoper

The main aim was to investigate the provenance of Viking age antler material findings of moose and red deer from Sigtuna and from three sites on the island of Gotland in the Baltic sea. This was done by analysis of the stable isotopes of carbon, nitrogen and sulphur. Thre were never any living population of these mammals on Gotland during the Viking age.?34S-values of sulphur from this study was compared with earlier research and by studying maps of the Swedish bedrock. The ?34S-values were more like the ?34S-value for bedrock other than European granite.

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.

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).

Kvickrotsstudier: 1. Kvickrotens reaktion på myllningsdjup, kvävemängd och kväveplacering i konkurrens med gröda. 2. Reducerad glyfosatanvändning på trädad åkermark :

1. Reaction on burial depth and nitrogen availability and placement in competition with a crop In this trial it was investigated how couch grass (Elymus repens) changes its ability to compete in stands of wheat and barley with different burial depth and different amounts and placement of nitrogen. More knowledge in this area can be valuable in the attempt to decrease the use of herbicides and still keep the weeds under control. The trial was carried out in the summer of 2004 as an outdoor pot experiment. The pots contained 15 litres of soil with a surface of 0,06 m2.

Miljöpåverkan av äggproduktion : En jämförelse mellan Lilluns ägg och andra svenska äggproducenter

The purpose of this report was to compare Lilluns egg production with other Swedish egg producers based on the flow of nutrients (nitrogen, phosphorus and potassium) in the egg production systems. The main focus in the report was the utilization rate of the forage and the excess of nutrients per kg egg. Additionally, the purpose was to identify the environmental impact from Lilluns egg production and compare the results with other egg producers. The inflow of nutrients associated with forage and poultry was compared with the nutrients that were exported from the production. All of the egg producers in this study had an excess of nutrients.

Foderbetor och kogödsel som substrat för biogasproduktion; anaerob mesofil samrötning i labbskala

One of Sweden?s sixteen national environmental objectives strives to decrease the impact on the climate. By 2020, green house gas emissions should be 40 % less compared to the levels of 1990 and a minimum of 50 % of the energy consumption should come from renewable energy sources. Because of this there is a great need of increasing the production of renewable energy. This is where biogas comes in as a competitive alternative.

Batch flow behandling och kontinuerligt flöde av lakvatten i en rotzonsanläggning : En jämförande studie i pilotskala

This report deals with the performance of a batch flow treatment of landfillleachate compared with a continuous flow system. The parameters in focus were total Kjeldahl nitrogen (TKN), BOD5 and COD. The pilot-scale experiment used eight barrels with a volume of 150 liters. Each barrel was constructed differently concerning its flow, its bed material grain size and its presence of plants or not. Four of the barrels worked in batch mode, thus four in continuous flow mode.

Effekter av kalavverkning på mindre boreala sjöars vattenkvalitet

Forestry is an important industry in Sweden, with clear-cut as the most commonly used method for harvesting. Here the long-term impact of clear-cut on lake water quality (dissolved organic carbon (DOC), nitrogen, phosphorus and pH) has been investigated, based on 23 lakes sampled during autumn. Data for additional 15 lakes sampled for the Swedish monitoring program were also used. Lakes were classified as 5, 25, 40 and 60 year based on data of the forest age in the catchment, gathered from the Swedish national forest inventory. Clear-cut lakes were classified as 5 years (>20% of the catchment clear-cut during the last 10 years).

Lyviken : -bedömning av dagvattenkvalitet

AbstractStormwater is defined as rain- and melted water. Ludvika kommun had little knowledgde about the stormwater that reaches a specific recipient Lyviken. Therefore they intended to do an research of the stormwater that leads down to Lyviken. The aim with this study was to assess the quality of the contents in the stormwater based on pH, conductivity, phosphorous, nitrogen, bacterias, oil and one sample that meassured the value of several methals. Since the population has increased for decades, the area of hard surfaces and asphalts areas also has increased. This can increase the pollutions that finally ends up in the recipient.

Utvärdering av avloppsvattenreningen vid Hallsta Pappersbruk : Kartläggning av inkommande avloppsvatten och optimering av driftparametrar

Hallsta paper mill uses large amounts of water during the pulp and paper making processes. The wastewater is treated in two separate activated sludge processes referred to as BIO 1 and BIO 2. The main aim is to reduce the organic substance content, measured as COD (Chemical Oxygen Demand) before the wastewater is released into the environment. Since the effluent produced is very rich in organic substances, the addition of nitrogen (N) and phosphorus (P) are necessary to give satisfactory treatment results. Problems with sludge bulking sometimes occur which lead to increased levels of suspended matter and nutrients in the effluent.

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