947 resultados para Nitrogen pollution
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Selostus: Kauran ytimen β-glukaanipitoisuus
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Diplomityössä luotiin katsaus sellu- ja paperiteollisuuden haitallisimpiin ilmapäästöihin ja ilmapäästömäärien kehitykseen Suomessa 1990-luvun alusta nykypäivään. Työssä tutustuttiin sellu- ja paperiteollisuuden ilmapäästöjä rajoittavan lainsäädännön ajankohtaisiin asioihin Suomessa ja Euroopan Unionissa, sekä tarkasteltiin nykyisen lainsäädännön perustana olleita ilmastosopimuksia eli kansainvälisen ilmastopolitiikan syntyä ja kehittymistä. Työssä on myös selvitetty ilman osuutta paperinvalmistuksessa, tutustuttu ilmapäästöjen rajoittamismenetelmiin ja eri mittausmenetelmiin ilmapäästöjen toteamiseksi. Työn puitteissa suoritettiin mittalaitetestejä eri paperitehtailla. Haitallisimpia ja määrällisesti suurimpia ilmapäästöjä sellu- ja paperiteollisuudessa ovat typen ja rikin oksidit, pelkistyneet rikkiyhdisteet, hiukkaset, haihtuvat orgaaniset yhdisteet (VOC) ja hiilidioksidi. Ilmapäästömäärät Suomessa ovat typenoksideja lukuun ottamatta olleet laskussa 1990-luvun alusta nykypäivään. Tärkein kasvihuonekaasu on hiilidioksidi, jonka määrää rajoitetaan Kioton sopimuksessa. Vuoden 2002 aikana selvinneekin, mikä on Kioton sopimuksen vaikutus Suomen metsäteollisuuteen. Päästömittauksia tarvitaan lainsäädännön raja-arvojen toteamiseksi, mittauksia suorittavat sertifioidut päästömittauslaboratoriot. Suoritetuissa mittalaitetesteissä havaittiin mittalaitteiden soveltuvuudessa kosteiden paperiprosessin poistokaasujen määrittämiseen suuria eroja.
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Tutkimuksen tarkoituksena oli selvittää typenoksidien vähennysmahdollisuudet Stora Enson Varkauden tehtaiden sellutehtaalla ja voimalaitoksella. Tutkimuksessa käsiteltiin tehdasalueen suurimpia typenoksidien päästölähteitä: soodakattilaa, meesauunia, kuorikattilaa, öljykattilaa ja muovi-alumiinijakeen kaasutuslaitosta. Tutkimuksessa selvitettiin typenoksidipäästöjen syntymekanismit ja erilaisiin polttotekniikoihin soveltuvat typenoksidien vähennystekniikat. Varkauden tehtaiden typenoksidien vuosipäästö vuonna 2001 oli 836 tonnia. Kansallinen lainsäädäntö, kansainväliset sopimukset sekä paras käytettävissä oleva tekniikka (BAT) huomioiden selvitettiin kuhunkin kohteeseen parhaiten soveltuvat ratkaisut. Tutkimuksen perusteella laadittiin toimenpideohjelma, joka määrittelee suositeltavan toteutusjärjestyksen typenoksidien vähennystoimenpiteille. Toimenpideohjelman tärkeimpinä kriteereinä pidettiin vuonna 2004 tulevan uuden ympäristöluvan arvioituja luparajoja sekä toimenpiteiden kustannustehokkuutta. Toteutusjärjestyksessä ensimmäiseksi valittiin koeajojakson järjestäminen ajon optimoimiseksi kiertopetikattilalla ja toiseksi meesauunin ajon optimointi jatkuvatoimisen NOx-analysaattorin avulla. Seuraaviksi toimenpiteiksi ehdotettiin vertikaali-ilmajärjestelmän käyttöönottoa soodakattilalla sekä SNCR-järjestelmän asennusta kuorikattilalle. Saavutettava NOx-vähennys tulisi olemaan 10 – 45 % ja hinta 30 – 3573 EUR vähennettyä NOx-tonnia kohti. Tutkimuksen osana Ilmatieteen laitoksella teetetyn typenoksidien leviämisselvityksen mukaan Stora Enson tehtaiden NOx-päästöjen vaikutus Varkauden ilmanlaatuun on hyvin pieni. Suurin osa NOx-päästöistä aiheutuu liikenteestä.
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The goal of this research was evaluated the effects of potassium and nitrogen fertilization on the plum (Prunus salicina) fresh fruit quality and after cold storage. The experiment was carried out in a five year-old plum orchard 'Reubennel', located at Araucaria County, Parana State, Southern Brazil, in a Haplumbrept Soil. Potassium fertilizer was applied at 55 and 110 kg/ha/year of K2O, as KCl. Nitrogen fertilizer was applied at 40, 80, 120, 160 and 200 kg/ha/year of N, as urea. It was used a split-plot design in a factorial scheme (2x5). One hundred plum fruits were harvested from each plot, in the same day, when 25 to 50% of the peel presented yellow-reddish color. At harvest and after 17, 27 and 37 days of storage at 0 ± 0.5 ºC, the flesh firmness, the total soluble solids, and the titratable acidity were assessed. Fresh fruit quality was affected by N application, with the best results obtained by applying 40 kg/ha/year of N. The N and K rate of 40 and 110 kg/ha/year, respectively, kept superior fruit quality during the storage. 'Reubennel' cold storage can not exceed 27 days. Fresh and stored 'Reubennel' plum fruit qualities depend on the N and K fertilizer rates.
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Biofilters degrade only a small fraction of the natural organic matter (NOM) contained in seawater which is the leading cause of biofouling in downstream processes. This work studies the effects of chemical additions on NOM biodegradation by biofilters. In this work, biofiltration of seawater with an empty bed contact time (EBCT) of 6 min and a hydraulic loading rate of 10 m h-1 reduces the biological oxygen demand (BOD7) by 8%, the dissolved organic carbon (DOC) by 6% and the UV absorbance at 254 nm (A254) by 7%. Different amounts of ammonium chloride are added to the seawater (up to twice the total dissolved nitrogen in untreated seawater) to study its possible effect on the removal of NOM by a pilot-scale biofilter. Seawater is amended with different amounts of easily biodegradable dissolved organic carbon (BDOC) supplied as sodium acetate (up to twice the DOC) for the same purpose. The results of this work reveal that the ammonium chloride additions do not significantly affect NOM removal and the sodium acetate is completely consumed by the biofiltration process. For both types of chemical additions, the BOD7, DOC and A254 in the outlet stream of the biofilter are similar to the values for the untreated control. These results indicate that this biofilter easily removes the BDOC from the seawater when the EBCT is not above 6 min. Furthermore, nitrogen does not limit the NOM biodegradation in seawater under these experimental conditions.
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This study was carried out to evaluate the yield, total N content in leaves and must composition of grapes from the Cabernet Sauvignon variety subjected to the application of urea and organic compost. Cabernet Sauvignon grapevines in Rosário do Sul, RS, Brazil, in 2008, 2009 and 2010 were subjected to annual application of 40 kg N ha-1 in the form of organic compost and urea, and compared to unfertilized grapevines. In the 2008/09, 2009/10 and 2010/11 crop seasons, leaves were collected for analysis of total N content. At maturation of the grapes, the yield and quality attributes of the must were evaluated. The application of N sources, especially organic compost, increased the N content in the whole leaf at full flowering. Application of organic compost and urea has little effect on grape yield and does not affect the total nutrient content in the must, nor the enological attributes.
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Tämän työn tarkoituksena oli löytää keinoja erään leijukerroskattilan typenoksidipäästöjen vähentämiseksi. Koska päästöt olivat jo alunperin alhaiset leijukerrostekniikan ja hybridin SNCR/SCR –typenpoistolaitteiston ansiosta, päätettiin päästöjä lähteä vähentämään parantamalla ammoniakkiruiskutuksen säätöä. Alkuperäinen ammoniakkiruiskutuksen säätö oli liian hidas, jotta satunnaisten häiriöiden aiheuttamat typenoksidipiikit olisi pystytty poistamaan. Ammoniakkiruiskutusta parannettiin lisäämällä jokaiseen ammoniakkilinjaan mäntäpumput, joiden avulla ammoniakkia voidaan syöttää sinne, missä sitä eniten tarvitaan. Ammoniakkiruiskutuksen säätöön kehitettiin uusi sumeaan logiikkaan perustuva säätäjä. Myös muita kehittyneitä säätömenetelmiä kuten neuroverkkoa hyödynnettiin säätäjän kehityksessä. Ammoniakkiruiskutuksen säätäjää testattiin menestyksekkäästi Ruotsissa Brista Kraftin Märstassa sijaitsevalla voimalaitoksella
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In 2008 the regional government of Catalonia (Spain) reduced the maximum speed limit on several stretches of congested urban motorway in the Barcelona metropolitan area to 80 km/h, while in 2009 it introduced a variable speed system on other stretches of its metropolitan motorways. We use the differences-in-differences method, which enables a policy impact to be measured under specific conditions, to assess the impact of these policies on emissions of NOx and PM10. Empirical estimation indicate that reducing the speed limit to 80 km h-1 causes a 1.7 to 3.2% increase in NOx and 5.3 to 5.9% in PM10. By contrast, the variable speed policy reduced NOx and PM10 pollution by 7.7 to 17.1% and 14.5 to 17.3%. As such, a variable speed policy appears to be a more effective environmental policy than reducing the speed limit to a maximum of 80 km/h.
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Growth experiments showed that adenine and hypoxanthine can be used as nitrogen sources by several strains of K. pneumoniae under aerobic conditions. The assimilation of all nitrogens from these purines indicates that the catabolic pathway is complete and proceeds past allantoin. Here we identify the genetic system responsible for the oxidation of hypoxanthine to allantoin in K. pneumoniae. The hpx cluster consists of seven genes, for which an organization in four transcriptional units, hpxDE, hpxR, hpxO and hpxPQT, is proposed. The proteins involved in the oxidation of hypoxanthine (HpxDE) or uric acid (HpxO) did not display any similarity to other reported enzymes known to catalyze these reactions, but instead are similar to oxygenases acting on aromatic compounds. Expression of the hpx system is activated by nitrogen limitation and by the presence of specific substrates, with hpxDE and hpxPQT controlled by both signals. Nitrogen control of hpxPQT transcription, which depends on 54, is mediated by the Ntr system. In contrast, neither NtrC nor NAC is involved in the nitrogen control of hpxDE, which is dependent on 70 for transcription. Activation of these operons by the specific substrates is also mediated by different effectors and regulatory proteins. Induction of hpxPQT requires uric acid formation, whereas expression of hpxDE is induced by the presence of hypoxanthine through the regulatory protein HpxR. This LysR-type regulator binds to a TCTGC-N4-GCAAA site in the intergenic hpxD-hpxR region. When bound to this site for hpxDE activation, HpxR negatively controls its own transcription.
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BACKGROUND & AIMS: Protein and energy requirements in critically ill children are currently based on insufficient data. Moreover, longitudinal measurements of both total urinary nitrogen (TUN) and resting energy expenditure (REE) are lacking. The aim of this study was to investigate how much protein and energy are needed to equilibrate nitrogen and energy balances in ventilated critically ill children on the basis of daily measurements of TUN, REE and protein and energy intakes. Comparisons were made with the guidelines of the American Society for Parenteral and Enteral Nutrition and the Dietary Reference Intakes. METHODS: Children with an expected duration of mechanical ventilation ≥72 h were prospectively recruited. TUN was measured by chemiluminescence, and REE was measured by indirect calorimetry. Generalised linear models for longitudinal data were used to study the relation between protein intake and nitrogen balance and to calculate the minimum intake of protein needed to achieve nitrogen equilibrium. A similar approach was used for energy. Results were compared to the recommended values. RESULTS: Based on 402 measurements performed in 74 children (median age: 21 months), the mean TUN was high at 0.20 (95% CI: 0.20, 0.22) g/kg/d and the REE was 55 (95% CI: 54, 57) kcal/kg/d. Nitrogen and energy balances were achieved with 1.5 (95% CI: 1.4, 1.6) g/kg/d of protein and 58 (95% CI: 53, 63) kcal/kg/d for the entire group, but there were differences among children of different ages. Children required more protein and less energy than the Dietary Reference Intakes. CONCLUSIONS: In critically ill children, TUN was elevated and REE was reduced during the entire period of mechanical ventilation. Minimum intakes of 1.5 g/kg/d of protein and 58 kcal/kg/d can equilibrate nitrogen and energy balances in children up to 4 years old. Older children require more protein.
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Two speed management policies were implemented in the metropolitan area of Barcelona aimed at reducing air pollution concentration levels. In 2008, the maximum speed limit was reduced to 80 km/h and, in 2009, a variable speed system was introduced on some metropolitan motorways. This paper evaluates whether such policies have been successful in promoting cleaner air, not only in terms of mean pollutant levels but also during high and low pollution episodes. We use a quantile regression approach for fixed effect panel data. We find that the variable speed system improves air quality with regard to the two pollutants considered here, being most effective when nitrogen oxide levels are not too low and when particulate matter concentrations are below extremely high levels. However, reducing the maximum speed limit from 120/100 km/h to 80 km/h has no effect – or even a slightly increasing effect –on the two pollutants, depending on the pollution scenario. Length: 32 pages
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During the last few years, the discussion on the marginal social costs of transportation has been active. Applying the externalities as a tool to control transport would fulfil the polluter pays principle and simultaneously create a fair control method between the transport modes. This report presents the results of two calculation algorithms developed to estimate the marginal social costs based on the externalities of air pollution. The first algorithm calculates the future scenarios of sea transport traffic externalities until 2015 in the Gulf of Finland. The second algorithm calculates the externalities of Russian passenger car transit traffic via Finland by taking into account both sea and road transport. The algorithm estimates the ship-originated emissions of carbon dioxide (CO2), nitrogen oxides (NOx), sulphur oxides (SOx), particulates (PM) and the externalities for each year from 2007 to 2015. The total NOx emissions in the Gulf of Finland from the six ship types were almost 75.7 kilotons (Table 5.2) in 2007. The ship types are: passenger (including cruisers and ROPAX vessels), tanker, general cargo, Ro-Ro, container and bulk vessels. Due to the increase of traffic, the estimation for NOx emissions for 2015 is 112 kilotons. The NOx emission estimation for the whole Baltic Sea shipping is 370 kilotons in 2006 (Stipa & al, 2007). The total marginal social costs due to ship-originated CO2, NOx, SOx and PM emissions in the GOF were calculated to almost 175 million Euros in 2007. The costs will increase to nearly 214 million Euros in 2015 due to the traffic growth. The major part of the externalities is due to CO2 emissions. If we neglect the CO2 emissions by extracting the CO2 externalities from the results, we get the total externalities of 57 million Euros in 2007. After eight years (2015), the externalities would be 28 % lower, 41 million Euros (Table 8.1). This is the result of the sulphur emissions reducing regulation of marine fuels. The majority of the new car transit goes through Finland to Russia due to the lack of port capacity in Russia. The amount of cars was 339 620 vehicles (Statistics of Finnish Customs 2008) in 2005. The externalities are calculated for the transportation of passenger vehicles as follows: by ship to a Finnish port and, after that, by trucks to the Russian border checkpoint. The externalities are between 2 – 3 million Euros (year 2000 cost level) for each route. The ports included in the calculations are Hamina, Hanko, Kotka and Turku. With the Euro-3 standard trucks, the port of Hanko would be the best choice to transport the vehicles. This is because of lower emissions by new trucks and the saved transport distance of a ship. If the trucks are more polluting Euro 1 level trucks, the port of Kotka would be the best choice. This indicates that the truck emissions have a considerable effect on the externalities and that the transportation of light cargo, such as passenger cars by ship, produces considerably high emission externalities. The emission externalities approach offers a new insight for valuing the multiple traffic modes. However, the calculation of the marginal social costs based on the air emission externalities should not be regarded as a ready-made calculation system. The system is clearly in the need of some improvement but it can already be considered as a potential tool for political decision making.
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The main aim of this study was to develop the project management framework model which would serve as the new model to follow for upcoming projects at the Lappeenranta cement plant. The other goal was to execute the SNCR (selective non catalytic reduction) project successfully so that the nitrogen oxides emissions are below the stated emission limit when the new emission limit comes into effect beginning in July, 2008. Nitrogen oxides, project management aspects, SNCR and the invested system are explained in the theory part. In the practical part of the study, the SNCR project in the Lappeenranta cement plant was executed and the findings were documented. In order to reach the aim of this study, a framework of project management was made. The framework is based on the executed SNCR project, previous projects in the cement plant and on the available literature relating to the subject matter. The developed project turned out to be successful.