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323 Uppsatser om Nitrogen removal - Sida 5 av 22
Jordbrukets påverkan på Östersjön : en jämförelse av indikatorer för att beskriva näringsbelastningen
The Baltic Sea, due to its special conditions, is a unique and vulnerable marine environment. There are many pressures that have an impact on the sea and one of the major problems is the extensive flow of nutrients from land. The most visible effect of the supply of nutrients is the annual algal blooms.
One of the main sources of nitrogen and phosphorus supply is agriculture. Nutrient losses
from arable land have been increasing as agricultural production has intensified. At the end of the twentieth century an increased awareness of these problems led to the formation of organizations such as HELCOM and Baltic 21.
Optimering av biologisk fosfor och kvävereduktion i ett reningsverk för hushållsspillvatten
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.
Urlakning av järn ur arkeologiskt trä med dietylentriaminpentaättiksyra (DTPA): undersökning av koncentrationens påverkan på extraktionstakten
Uppsats för avläggande av filosofie kandidatexamen i Kulturvård, Konservatorsprogrammet 15 hpInstitutionen för kulturvårdGöteborgs universitet2015:06.
Kvävemineralisering från stallgödsel beroende på olika grad av inblandning i mark
The impact of the distribution in the soil volume of two farm manures on the net mineralization and immobilization processes of nitrogen were studied in an incubation experiment. Cattle slurry and broiler litter were placed in the soil with three procedures for incorporation including placement on top of the soil (TOP), in the middle of the soil (MID) and mixed homogenously with the soil (MIX). During the two weeks of incubation, few significant differences in net mineralization were seen between TOP, MID and MIX. However, there was a tendency that MIX led to a larger net immobilization of N than placement at one point (TOP and MID). This is also the result in the literature.
Synoptisk provtagning i vattendrag med eutrofieringsproblem : En studie för att identifiera områden för prioritering av åtgärder
In Halland, agriculture is the major source of eutrophication of water. In the study, synoptic sampling were performed in the three watercourses Nyrebäcken, Skintan and Vinån all located in the county of Halland. Sampling occurred during the period February to May on three occasions with different flow rates: high, low and base flow. Samples were taken in the mainstream and tributaries with intention to show how big the impact of eutrophication it is in the water and to assess the impact of the tributariesThe results show that all watercourses are affected by eutrophication. Nyrebäcken has the highest concentrations of nitrogen and phosphorus in the mainstream, then Skintan and last Vinån.
Membranbioreaktorteknik- en framtida lösning på Lundåkraverket? : Membrane bioreactors- A future solution at Lundåkra wastewater treatment plant?
Membrane bioreactors (MBR) combined with biological phosphorous treatment (Bio-P) has been investigated if that could be an alternative to the future expansion with conventional active sludge treatment at Lundåkra wastewater treatment plant (WWTP) in the proximity of Landskrona, Sweden.The results showed that the surface demand in the biological treatment will be reduced with 67% with the MBR-alternative compared to a conventional activated sludge process. The nutrient removal in the MBR-solution was decreased or unchanged for nitrogen-, phosphorous- and organic parameters. However, the energy demand will increase with an estimated cost of approximately 1 million SEK annually. Moreover, the extra chemical consumption is estimated to cost 370 000 SEK annually.The disturbances caused by filamentous bacteria such as sludge dispersal could be resolved with MBR-technology because the membranes are not affected by these organisms. The Bio-P process combined with MBR-technology works if the wastewater recirculates from the membranes to an aerobic zone.In the proposal, there will be a new pre-treatment step, for instance hole screens.
Riktlinjer för enskilt avlopp : Underlag för bedömning av normal och hög skyddsnivå i Köpings kommun
In Sweden, the eutrophication of lakes, water courses and the coastal areas is considered the major threat to aquatic ecosystems and therefore actions taken to reduce the nutrient load to aquatic system including the Baltic Sea has high priority. There are many different sources of phosphorous and nitrogen and domestic wastewater is one contributing factor to the high load. Especially waste water from households that is not connected to municipal sewage treatment or a local small scale plant with appropriate nutrient removal efficiency is considered a problem. These types of households are quite common in rural areas in Sweden and in areas where summer houses has been converted to permanent living. Swedish legislation now permit the municipalities to decide in which areas within the municipality higher demands of the local small scale treatment facility should be met by the households (i.e.
pH-sensitivity in boreal streams ? the influence of landscape characteristics
The goal of the society to increase the proportion of renewable energy has led to an increased demand of bioenergy e.g. forest biomass. However, there are concerns that removal of biomass will lead to decreased base cation concentrations in the soils and acidification of streams. In order to find in which types of landscape removal of branches and tops could have such negative effects, this study aims to analyse the relations between pH-sensitivity and landscape variables in the Bothnia Bay water district. GIS and digital geographical data were used to analyse the landscape in subcatchments.
Optimering av SNCR-system i en biobränsleeldad panna : möjligheter till minskade NOx-utsläpp för ENA Energi
Emission of nitrogen oxides as well as carbon monoxides is an inevitable result of combustion. A Swedish law "Law of environmental fee for emissions of nitrogen oxides as a result of energy production" (lagen om miljöavgift på utsläpp av kväveoxider vid energiproduktion (SFS 1990:613)) controls the emission of NOx from energy production by a system of fees. The system has resulted in a strong approach toward less emissions of NOx among the energy production plants. High emission levels, today exceeding 52 mg/MJsupplied fuel, leads to costs for energy production companies. This paper examines possibilities to reduce the emissions of NOx by optimization of the SNCR-technique in a biofuel fired heat and power plant.
Where has the fertilizer gone? Closing the nutrient budget for a eucalyptus fertilization experiment in southern China
An increasing demand for wood products in China has resulted in large areas invested in fast-growing tree plantations of eucalyptus. Eucalyptus plantations are often associated with an intensive management including fertilization. By understanding the effects of fertilization and where in the ecosystem nutrients are accumulated a more sustainable forest management could be achieved. In this study, a nutrient budget including all biomass and soil components was created for Eucalyptus urophylla. The examined nutrients were nitrogen, phosphorus and potassium.
Avskiljning av uran från dricksvatten med reaktiva filter :
Water is our most important provision and its quality is above all dependent on the
geological conditions in the area from where it is extracted. Due to geological
properties there are certain areas with an elevated risk of high uranium levels in the
ground water, which in turn constitutes a risk for human health. Consumption of water
that contains a high concentration of uranium implies a health risk due to the chemical
characteristics of uranium. Livsmedelsverket (The National Food Administration) and
Socialstyrelsen (The National Board of Health and Welfare) therefore recommend that
precautionary measures should be taken when the uranium concentration in ground
water exceeds 15 micrograms per litre. In particular, drinking water collected from
wells in areas with uranium-rich bedrock may have a harmfully high level of uranium.
One of the wells of the Ärla water purification plant, located near Eskilstuna, Sweden,
contains water that exceeds the guideline of 15 micrograms per litre.
One interesting technique for removing uranium from drinking water is adsorption to
reactive filter materials.
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.
Nitrogen fixation among boreal feather mosses along a clear-cut chronosequence
The Swedish boreal forests are limited by nitrogen (N) availability. While biological N2 fixation by cyanobacteria hosted by pleurocarpous feather mosses are important sources of N input to natural boreal forest ecosystems, little is known about the patterns of N2 fixation in silvicultural systems. This study investigates the biological N2 fixation rates of two boreal feather moss species (Pleurozium schreberi and Hylocomium splendens) along a chronosequence from clear-cut to mature forest, as well as the vegetation characteristics along the chronosequence. Measurements and samples were collected from 32 forest sites that were classified into four age classes (clear-cut, pre-commercially thinned, thinned and mature forest). The sites were located near the city of Arvidsjaur in northern Sweden.
Effekter på antalet vårdrelaterade urinvägsinfektioner av nya rutiner för kateteranvändning
Introduction Every tenth patient in Sweden is affected by nosocomial infections. Among these, urinary tract infection (UTI) is the most frequently occurring within the hospital environment. Nosocomial infections lead to increasing costs for care, more suffering among the patients, increasing use of antibiotics, and longer treatment spells. The Academic hospital have engaged all wards in the so called VRISS-project (?nosocomial infections must be stopped?) in order to reduce the number of nosocomial infections.Aim In connection to the VRISS-project new routines for removal of uretrahl catheters are introduced at ward 70E2 at the Academic hospital.