Made available in DSpace on 2014-07-29T14:52:05Z (GMT). No. of bitstreams: 1 FABIANO ANDRE PETTER.pdf: 2453719 bytes, checksum: da5399318ecc7cdd53eb39e42af320d6 (MD5) Previous issue date: 2010-07-02 / The effect of biochar on the chemical and biological soil properties, on the physiological response and productivity of soybean and upland Rice and on N2O emission was investigated. The study was carried out in Nova Xavantina, Mato Grosso state between September 2006 and May 2009 on two different soil types: Haplic Ferralsol (soybean) and Dystric Cambisol (rice). The experimental design was a combination of strips and random blocks where 5 doses (0 kg ha-1, 100 kg ha-1, 200 kg ha-1, 300 kg ha-1 e 400 kg ha-1) of NPK (0-20-20) were distributed in strips and 5 doses of biochar (0 Mg ha-1, 2 Mg ha-1, 4 Mg ha-1, 8 Mg ha-1 e 16 Mg ha-1) in random a manner in the case of soybean and 4 doses (0 kg ha-1, 100 kg ha-1, 200 kg ha-1 and 300 kg ha-1) of NPK (05-25-15) were distributed in strips and 4 doses of biochar (0 Mg ha-1, 8 Mg ha-1, 16 Mg ha-1 and 32 Mg ha-1) in random a manner in the case of rice. For rice urea was applied as top dressing corresponding the NPK doses: 0 kg ha-1, 15 kg ha-1, 32 kg ha-1 e 50 kg ha-1 de N, respectively. Every treatment had 4 replications. The biochar was applied only once, before the instalation of the experiments to the 0-15 cm soil layer. Soil fertility parameters were evaluated in samples collected at 0-10 cm, 10-20 cm and 20-30 cm and pH, Ca, Mg, Al, H+Al, P, K, Cu, Zn, Fe, Mn, SOM and total C and N were measured. Among physiological parameters the height and dry mass of plants were evaluated plus the nutrient levels in plant tissue at flowering and yield. The evaluation of soil biological parameters included the basal respiration rate of the soil (C-CO2) and the microbial biomass carbon (MBC). Nitrous oxide (N2O) emissions were also measured. Total C was significantly higher at 0-10 cm in the 1st year after biochar application and at 10-20 cm in the 3rd year in the treatment with 16 Mg ha-1 biochar. There was interaction between biochar and NPK, resulting in increase in K levels at 0-10 cm, 1st and 3rd year after application of biochar and decrease in exchangeable acidity in the 1st year. The 8 Mg ha-1 and 16 Mg ha-1 biochar doses resulted in higher values of plant height and dry mass both in the 1st and 3rd year, however, biochar had no effect on nutrient levels in plant tissue. Soybean yields were, again, significantly affected by biochar doses in a positive and quadratic manner both in the 1st and 3rd year. There was a significant increase in P, Ca, levels and pH, and Al and exchangeable acidity (H+Al) were reduced at 0-10 cm in the treatments with 32 Mg ha-1 biochar. Similar effect was observed for (H+Al) and K at 10-20 cm. Biochar had no effect on other soil chemical parameters. It negatively affected the dry mass of the plants at 25 and 55 DAP, however, did not have influence on plant height. Rice yield was directly and linearly influenced by biochar doses. Increase in nutrient use efficiency (N, P, K) was also observed at the highest biochar dose (32 Mg ha-1). Biochar had no effect on C-CO2 and MBC but seu uso resulted in higher emission rates of N2O at the 32 Mg ha-1 dose. In conclusion, in general, biochar had similar effects on soil chemical properties and yields, however its effect was manifested in a greater manner (larger contrast) in the more sandy soil. It increased nutrient use efficiency. As of plant height and dry mass, soybean gave better response for biochar application than rice. Finally, biochar seems to maintain its effect on yield and increases its effect on SOM accumulation over time. / Estudou-se o efeito do carbono pirogênico nas características químicas e biológicas do solo, na fisiologia e produtividade das culturas da soja e do arroz de terras altas e na emissão de N2O para a atmosfera. Os experimentos foram realizados em Nova Xavantina, MT, em dois diferentes tipos solos: Latossolo Vermelho Amarelo (soja) e Cambissolo Háplico (arroz) em delineamento experimental com junção de faixas e blocos ao acaso, em que 5 doses (0 kg ha-1, 100 kg ha-1, 200 kg ha-1, 300 kg ha-1 e 400 kg ha-1) de NPK (0-20-20) e 5 doses de carvão vegetal (0 Mg ha-1, 2 Mg ha-1, 4 Mg ha-1, 8 Mg ha-1 e 16 Mg ha-1), no caso da soja, e 4 doses (0 kg ha-1, 100 kg ha-1, 200 kg ha-1 e 300 kg ha-1) de NPK (05-25-15) e 4 doses de carvão (0 Mg ha-1, 8 Mg ha-1, 16 Mg ha-1 e 32 Mg ha-1), no caso do arroz, foram aplicadas, para o carvão ao acaso, em 4 repetições (blocos). Combinado com NPK na cultura do arroz foi realizada aplicação de 0, 15, 32 e 50 kg ha-1 de N em cobertura, respectivamente. Para avaliação de fertilidade do solo foram coletadas amostras de solo nas camadas de 0-10 cm, 10-20 cm e 20-30 cm e analisados os seguintes atributos: pH, Ca, Mg, Al, H+Al, P, K, Cu, Zn, Fe, Mn, M.O., C orgânico e N total. Os parâmetros fisiológicos avaliados foram: altura, matéria seca, teor foliar dos nutrientes P, K, Ca e Mg, Fe, Cu, Zn e Mn em pleno florescimento e produtividade. A avaliação dos parâmetros biológicos do solo consistiu na determinação da taxa de respiração basal do solo (C-CO2) e carbono da biomassa microbiana (CBM). Foi avaliado a emissão de N2O para a atmosfera. Na cultura da soja houve aumento significativo nos teores de C total de 0-10 cm no 1° ano e 10-20 cm no 3° ano com a aplicação de 16 Mg ha-1de carvão. Verificou-se efeito na interação carvão e NPK, com aumento de K e na camada de 0-10 cm no 1° e 3° ano e acidez potencial apenas no 1° ano. As doses de 8 Mg ha-1 e 16 Mg ha-1 proporcionaram maiores alturas e massa seca nas épocas avaliadas. Não se verificou efeito nos teores foliares de nutrientes. A produtividade foi significativamente aumentada em razão da aplicação de 16 Mg ha-1. Na cultura do arroz houve aumento significativo nos teores de P e Ca e no pH e redução de Al e H+Al na camada de 0-10 cm com a aplicação de 32 Mg ha-1de carvão. Esse efeito se repetiu para H+Al na camada de 10-20 cm e com aumento nos teores de K. Verificou-se efeito negativo do carvão na matéria seca aos 25 e 55 DAP, todavia não influenciou a altura das plantas. A produtividade foi aumentada à medida que se aumentou as doses de carvão. Observou-se maior eficiência no uso do N, P e K na dose de 32 Mg ha-1. Não se verificou efeito significativo do carvão no C-CO2 e CBM. Observou-se os maiores fluxos de N2O para a atmosfera na presença de 32 Mg ha-1. Como conclusão geral, o carvão vegetal teve efeito similar nas propriedades de fertilidade do solo e produtividade das plantas nos dois experimentos, entretanto seu efeito foi mais fortemente manifestado (maior contraste) no solo mais arenoso. Aumentou ainda a eficiência de uso de nutrientes. Considerando a altura das plantas e a massa seca a soja apresentou melhor resposta para a aplicação de carvão no solo. Finalmente, o carvão vegetal manteve seu efeito na produtividade e aumentou a acumulação da M.O. no solo com o passar do tempo.

Submitted by Biblioteca de Pós-Graduação em Geoquímica BGQ (bgq@ndc.uff.br) on 2017-04-27T16:58:25Z No. of bitstreams: 1 Dissertação Brotto, A. C.pdf: 1827218 bytes, checksum: d583ce8460c1efc5934c93cec6ef4c3d (MD5) / Made available in DSpace on 2017-04-27T16:58:25Z (GMT). No. of bitstreams: 1 Dissertação Brotto, A. C.pdf: 1827218 bytes, checksum: d583ce8460c1efc5934c93cec6ef4c3d (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / Universidade Federal Fluminense. Instituto de Química. Programa de Pós-Graduação em Geociências- Geoquímica Ambiental. Niterói, RJ / O estudo das emissões de óxido nitroso (N2O) em processos de tratamento de esgoto tem se tornado necessário e urgente nos últimos anos visto à sua contribuição às mudanças climáticas globais, já que este gás é responsável por 6% do efeito estufa e tem se tornado a principal substância destruidora do ozônio estratosférico do século XXI. Poucos são os estudos que quantificaram as emissões de N2O diretamente em estações de tratamento de esgoto (ETEs) e a literatura apresenta uma grande variação nos fatores de emissão (FEs) obtidos por eles. As Diretrizes de 2006 do IPCC para Inventários de Gases do Efeito Estufa sugerem o FE de 3,2 (2-8) g N2O pessoa-1 ano-1 para estimativas das emissões de N2O em ETEs, que corresponde a 0,035% do nitrogênio total (NT) emitido como N2O. As emissões de N2O em processo de tratamento de lodos ativados foram determinadas no período de janeiro a julho de 2010 em uma ETE municipal no Estado do Rio de Janeiro que trata aproximadamente 14,7 mil m3 dia-1 com média remoção de DQO para o período de estudo de 73% e carga de NT afluente de 46 mg N L-1. Os principais parâmetros operacionais relacionados às emissões de N2O em ETE foram estudados, a saber, concentração de oxigênio dissolvido (OD), concentração de nitrito (NO2 -), pH e temperatura. As maiores emissões de N2O foram observadas quando a concentração de OD se encontrava entre 1,3 e 3,4 mg L-1, o pH entre 5,9 e 6,5 e temperatura acima de 30oC. Enquanto as menores emissões ocorreram em concentrações de OD abaixo de 1,0 mg L-1 e acima de 4,0 mg L-1, e em pH acima de 6,5. O fluxo de N2O estimado é de 4,1 x 105 g N2O ano-1 e os FEs de N2O per capita, por vazão de esgoto tratado e pela carga NT afluente são 8,1 g N2O pessoa-1 ano-1, 8,0 x 10-5 g N2O L -1 e 0,12%. O FE per capita estimado exclusivamente para o tanque de aeração é aproximadamente 2,5 vezes superior ao proposto pelo IPCC (2006) para inventários de emissões de N2O para países que possuam sistemas centralizados de tratamento de esgoto com avançado controle dos processos de nitrificação e desnitrificação. / The study of nitrous oxide (N2O) emissions from wastewater treatment processes has become necessary and urgent in the last years due to its contribution to global climate change, since this gas is responsible for 6% of the global greenhouse effect and will become the main ozone-depleting substances (ODS) of the 21st century. Few studies have quantified the direct emissions of N2O from wastewater treatment plants (WWTPs) and literature shows a wide variation in the emission factors (EFs) obtained by them. 2006 IPCC Guidelines for National Greenhouse Gas Inventories suggests an EF to estimate N2O emissions from WWTP of 3.2 (2.8) g N2O person-1 yr-1, which corresponds to 0.035% of total nitrogen emitted as N2O. Emissions of N2O from a full-scale activated sludge process was determined from January to July of 2010 during measurement campaign at a municipal WWTP in the State of Rio de Janeiro that treat roughly 14,700 m3 day-1 with an average influent removal COD for the period of study of 73% and total nitrogen load (TN) of 46 mg N L-1. The most important operational parameters leading N2O emissions in WWTP were also studied, namely, dissolved oxygen concentration (DO), nitrite (NO2 -) concentration, pH and temperature. The largest emissions of N2O were observed when DO concentration was between 1.3 and 3.4 mg L-1, pH between 5.9 and 6.5 and temperatures above 30oC. While lower emissions occurred in DO concentrations below 1.0 mg L-1 and above 4.0 mg L-1, and at pH above 6.5. Total estimated annual flux of N2O is 4.1 x 105 g N2O yr-1 and the EF of N2O estimated per capita, wastewater flow and the influent TN load are 8.1 g N2O person-1 yr-1, 8.0 x 10-5 g N2O L(wastewater)-1 and 0.12%. The per capita EF estimated exclusively for the aeration tank is almost 3 times higher than that proposed by the IPCC (2006) for N2O emission inventories for countries that predominantly have advanced centralized WWTPs with nitrification and denitrification steps.

Dans ce travail nous avons étudié des réactions chimiques sur la surface de deux métaux :le platine et l'or, en utilisant la microscopie ionique à effet de champ électrique (FIM) et la spectrométrie de masse de désorption par champ pulsé (PFDMS). En complément de ces données expérimentales, nous apportons des résultats obtenus par la théorie de la fonctionnelle de la densité (DFT). La taille et la morphologie de nos échantillons font qu’ils sont de bons modèles de grains de phase active dans un catalyseur réel.<p>\ / Doctorat en sciences, Spécialisation chimie / info:eu-repo/semantics/nonPublished

Lustgas är en växthusgas, ca 300 gånger mer potent än koldioxid och som har potential att bryta ned ozonlagret med sin livslängd på 120 år i atmosfären. Lustgasutsläppen beräknas ha ökat med mellan 20–30% sedan förindustriell tid vilket tros bero på en ökad användning av konstgödsel i jordbrukssektorn men en del av all lustgas som bildas kommer från avloppsreningsverk vilka står för ca 1,6% av lustgasavgången till atmosfären där Henriksdals reningsverk bidrar med lustgasproduktion. Under 2021 beräknade man en lustgasavgång från Henriksdals reningsverk på ca 37 ton, vilket kan jämföras med klimatavtrycket på 10 000 nyregistrerade bilar vid körningar på ca 1500 mil/år. Syftet med rapporten var att undersöka om det gick att beräkna mängden kväve i avgående lustgas och jämföra det med hur mycket av den beräknade lustgasen som avgår till luft av andelen renat ammonium, samt att undersöka olika strategier för minimering av lustgasproduktion. Det finns flera vägar till lustgasbildning i de biologiska reningsprocesserna i verket. Tre huvudspår finns dock till lustgasbildning varav autotrof nitrifikation var aktuell för detta examensarbete. Flera driftsstrategier finns att tillgå för att undersöka hur lustgasproduktion påverkas av olika faktorer. Under detta examensarbete undersöktes en av dessa, syrebörvärden, där ett fast syrevärde i den luftade bassängen antingen skulle minska eller öka lustgasproduktionen beroende på luftningsintensitet och ammoniumkoncentration i vattnet. Lustgasavgången beräknades bestå till 0,19% av kväve renat från ammoniumbelastningen. Resultatet visade att vid låga syrehalter i vattnet fanns en lägre andel lustgasbildning jämfört med högre luftningsintensitet. Nackdelen blev dock att andelen renad ammonium sjönk i blocket. Vid högre luftningsintensitet var lustgasavgången högre i ett av huvudscenariona. I det andra scenariot med hög luftning var andelen renat ammonium lägre än i första scenariot, men med låga lustgashalter. Slutsatsen blev att lustgas kan bildas under olika förutsättningar men att under just den här studien var lustgasproduktionen som högst när nitrifikationen var som mest effektiv. / Nitrous oxide is a greenhouse gas, almost 300 times more potent than carbon dioxide, and which has the potential to deplete the ozone layer with its lifetime of 120 years in the atmosphere. Nitrous oxide emissions are estimated to have increased between 20–30% since pre-industrial times, which is believed to be due to increased use of artificial fertilizers in the agricultural sector, but part of all nitrous oxide that is formed comes from wastewater treatment plants, which account for approx. 1.6% of nitrous oxide emissions to the atmosphere where Henriksdals treatment plants contribute to nitrous oxide production. In 2021, nitrous oxide emissions from Henriksdal's treatment plant were calculated to be approximately 37 tons, which can be compared to the climate footprint of 10,000 newly registered cars driven approximately 15 000 km per year. The aim of the report was to investigate whether it was possible to calculate the amount of nitrogen in outgoing nitrous oxide to compare it with how much of the calculated nitrous oxide is emitted to air from the proportion of purified ammonium, as well as to investigate different strategies for minimizing nitrous oxide production. There are several routes to the formation of nitrous oxide in the biological purification process in the plant. There are, however, three main tracks for nitrous oxide formation, of which autotrophic nitrification was relevant for this degree project. Several operational strategies are available to investigate how nitrous oxide production is affected by various factors. During this thesis, one of these, oxygen set-point, was investigated, where a fixed oxygen value in the aerated basin would either decrease or increase nitrous oxide production depending on aeration intensity and ammonium concentration in the water. The nitrous oxide discharge was calculated to consist of 0.19% nitrogen purified from the ammonium load. The result showed, that at low oxygen levels in the water, there was a lower proportion of nitrous oxide formation compared to higher aeration intensity. The disadvantage, however, was that the proportion of purified ammonium decreased in the block. At higher aeration intensity, nitrous oxide emissions were higher in one of the main scenarios. In the second scenario with high aeration, the proportion of purified ammonium was lower than in the first scenario, but with low levels of nitrous oxide. The conclusion was that nitrous oxide can be formed under different conditions, but during this study, nitrous oxide production was highest when nitrification was most efficient.

This thesis has, commissioned by Dräger, an international company at the forefront of medical and safety technology, examined how the use of inhalational anesthetics affects the climate and environment. The purpose of this work is to examine how the Swedish healthcare sector currently works with inhalational anesthetics, how different anesthetic machines affect the emissions, as well as alternatives available to reduce anesthetic gases emissions. Climate change is a current issue in today’s society, but the impact of anesthetic gases on the climate is not widely known, despite their everyday use in the healthcare sector. Through data collection from two Swedish hospitals; Linköping University Hospital and Örebro University Hospital, an interview with medical and medical engineering staff, as well as a literature study the main question of the thesis could be answered; How do the most common anesthetic gases affect the environment? The results are presented in the form of diagrams showing the amount of anesthetic gas used in the aforementioned hospitals during surgeries. The results have been analyzed and discussed based on the research questions, and the different results from each hospital have been compared to each other. It can be seen that Dräger’s anesthesia machines have a relatively low consumption of sevoflurane, but it is impossible to draw any definitive conclusions due to lack of data, and lack of access to machines from other manufacturers. / Detta examensarbete har, på uppdrag av Dräger, ett internationellt företag i framkant inom medicin- och säkerhetsteknik, undersökt hur användning av inhalationsanestetika påverkar miljön. Målet med arbetet är att undersöka hur den svenska sjukvården för närvarande arbetar med inhalationsanestetika, hur olika anestesimaskiner påverkar utsläppen, samt alternativ som finns tillgängliga för att minska dessa utsläpp. Klimatförändringar är en aktuell fråga i dagens samhälle men påverkan av anestesigaser på klimatet är inte allmänt känt, trots att dessa används dagligen i hälsovården. Genom datainsamling från två svenska sjukhus; Linköpings Universitetssjukhus och Örebro Universitetssjukhus, intervjuer med medicinsk- och medicinteknisk personal, samt en litteraturstudie har arbetets problemställning besvarats; Hur påverkar de mest frekvent använda anestesigaserna miljön? Resultaten visar i diagramform hur mycket anestesi gas som använts i tidigare nämnda sjukhus under operationer. Resultaten har analyserats och diskuterats utifrån forskningsfrågorna, dessutom har de olika resultaten från respektive sjukhus jämförts med varandra. Det kan ses att Drägers anestesimaskiner har en relativt låg konsumtion av sevofluran, men brist på data samt brist på tillgång till maskiner från andra producenter gör det omöjligt att dra en konkret slutsats.

Energie und Rohstoffe auf Basis von Biomasse gelten als wichtiger Beitrag, um den anthropogen begründeten Klimawandel zu mindern. Diese publikationsbasierte Arbeit analysiert, inwiefern Aussagen über Vorzüglichkeit von Biomassenutzung im direkten Vergleich oder auch in komplexeren wirtschaftlichen Nutzungssystemen durch Unsicherheiten in den Treibhausgasemissionen (THG) oder durch die Anwendung der Bewertungsmethodik beeinflusst werden. Eine Fallstudie zur stationären Biostromerzeugung aus der Vergasung von Pappelhackschnitzeln zeigte mittels Monte-Carlo-Analyse, dass dieser Biostrom trotz Unsicherheiten weniger THG emittiert bzw. sogar Kohlendioxid sequestrieren könnte. Die zweite Fallstudie analysierte Biomassenutzung im Systemzusammenhang. Sie bezog neben THG-Emissionen als Bewertungskriterien sowohl den Bedarf an Agrarfläche als auch an fossilen Ressourcen mit ein. Für das Beispiel der Häuserdämmung mittels Hanffasern oder Styropor konnte aus den drei Kriterien auch unter Berücksichtigung mehrerer Szenarien keine eindeutige Vorzugslösung der Biomassenutzung abgeleitet werden. Basierend auf dem Produktivitätskonzept stellt der dritte Beitrag mit CUDe (Carbon Utilization Degree) einen Ansatz vor, wie die Nutzungseffizienz des in der Biomasse bereitgestellten Kohlenstoffs bewertet werden könnte. THG-Minderungsrechnungen erfordern eine fundierte Kenntnis der Methode als auch des Produktionssystems in seinem regionalen Kontext. Als Landnutzungseffekte sollten neben Änderungen im Bodenkohlenstoffgehalt auch Unterschiede in Lachgas-Hintergrundemissionen von annuellen gegenüber mehrjährigen Kulturen berücksichtigt werden. Trade-Offs sprechen dafür, Biomassenutzungssysteme nicht nur hinsichtlich Klimawirksamkeit zu optimieren. Ergänzend könnte Kohlenstoff auch als Ressource betrachtet und mit Effizienzkriterien bewertet werden. Biomassenutzung ließe sich so optimieren, dass gemeinsam mit Klimaschutz weitere aktuelle Handlungsfelder adressiert werden. / Biomass-based energy and materials are considered important for the mitigation of human-induced climate change and as relevant bioeconomic feedstock. This publication-based dissertation aims to contribute to the discussion about the reliability of mitigation assessment of biomass applications in an increasingly bio-based, low-carbon economy that also fulfils sustainability constraints of resource conservation. It analysed how preference of biomass use in direct comparison as well as in larger economic context is affected by single uncertainties as well as by mitigation calculation methods. A case study on stationary bioelectricity generation from poplar wood chip gasification with a Monte Carlo approach showed that such bioelectricity could emit less greenhouse gases (GHG) or even sequester carbon despite existing uncertainties. The second case study analysed biomass use in a systemic context. Besides GHG emissions also resource demand of cropland and fossil fuels were used to assess two strategies to isolate buildings. From the three criteria, none of the strategies would clearly be preferred. The third case study presented an approach to assess the efficiency of biomass carbon use (CUDe; Carbon Utilization Degree) and applied it exemplarily to a biogas and a hemp insulation system. GHG mitigation analyses of biomass use must be performed with profound knowledge of the methodology and the biomass system in its regional context. In land use change assessment, emissions resulting from deviating nitrous oxide baselines from annual and perennial crops should be considered in addition to carbon stock changes. Optimization of biomass applications only with respect to GHG emissions (or other single criteria) might overlook trade-offs. However, multi-criteria analyses might yield ambiguous results. A resource-efficient viewpoint on biogenic carbon use instead of its sole GHG implications might help to foster a transformation to bio-based, low-carbon economies.

A two-year lysimeter study was undertaken to compare the environmental effects (e.g. nitrate leaching and nitrous oxide emissions) of soil applied lactose-depleted dairy factory effluent (LD-DFE) with lactose-rich DFE. The aim of this experiment was to determine the fate of nitrogen from LD-DFE and dairy cow urine applied to a Templeton fine sandy loam soil (Udic Ustrochrept), supporting a herbage cover of ryegrass (Lolium perenne) and white clover (Trifolium repens). Measurements were carried out on the amount of nitrogen lost from the soil via leaching, lost by denitrification, removed by the pasture plants, and immobilized within the soil organic fraction. Further, a comparison between the fate of nitrogen in LD-DFE irrigated onto land under a "cut and carry" system, as opposed to a "grazed" pasture system was undertaken. Lactose-depleted dairy factory effluent was applied at three-weekly intervals during the summer months at rates of 25 and 50 mm, until nitrogen loading targets of 300 and 600 kg N ha⁻¹ yr⁻¹ had been achieved. Measured leaching losses of nitrogen averaged 2 and 7 kg N ha⁻¹ yr⁻¹ for Control 25 and Control 50 treatments; 21, 20 and 58 kg N ha⁻¹ yr⁻¹ for 25 and 50 mm "cut and carry" treatments respectively; and 96 kg N ha⁻¹ yr⁻¹ for the 25 mm "grazed" treatment. The range of nitrate-N leaching loss from LD-DFE plus urine is no different from the lactose-rich DFE nitrate leaching loss. Uptake of nitrogen by the growing pasture averaged 153, 184,340,352,483, and 415 kg N ha⁻¹ yr⁻¹ for Control 25, Control 50, LD-DFE 25 and LD-DFE 50 mm "cut and carry" treatments, and the LD-DFE 25 mm "grazed" treatment, respectively. Denitrification losses were 0.06, 4.4, 1.69, 19.70, and 7.4 kg N ha⁻¹ yr⁻¹ for Control 25, the LD-DFE 25 "cut and carry" treatments, the LD-DFE 25 mm "grazed" treatment, and calculated "paddock losses", respectively. Isotopic nitrogen studies found that 29.4 and 25.8% of applied LD-DFE nitrogen was immobilised in the LD-DFE 25 and LD-DFE 50 "cut and carry" treatments. The results of this experiment confirm the findings of the previous lactose-rich DFE study, in that the effects of grazing stock are of greater environmental concern than the removal of lactose from the effluent waste stream.

No description available.

No description available.

A radio frequency (rf) quadrupole instrument, currently known as an Isobar Separator for Anions (ISA), has been integrated into an Accelerator Mass Spectrometry (AMS) system to facilitate anion–gas reactions before the tandem accelerator. An AMS Cs+ sputter source provided > 15 keV ions that were decelerated in the prototype ISA to < 20 eV for reaction in a single collision cell and re-accelerated for AMS analysis. Reaction based isobar suppression capabilities were assessed for smaller AMS systems and a new technique for gas–phase reaction studies was developed. Isobar suppression of 36S– and 12C3– for 36Cl analysis, and YF3– and ZrF3– for 90Sr analysis were studied in NO2 with deceleration to < 12 eV. Observed attenuation cross sections, σ [x 10^–15 cm^2], were σ(S– + NO2) = 6.6, σ(C3– + NO2) = 4.2, σ(YF3– + NO2) = 7.6, σ(ZrF3– + NO2) = 19. With 8 mTorr NO2, relative attenuations of S–/Cl– ~ 10^–6, C3–/Cl– ~ 10^–7, YF3–/SrF3– ~ 5 x 10^–5 and ZrF3–/SrF3– ~ 4 x 10^–6 were observed with Cl– ~ 30% and SrF3– > 90% transmission. Current isobar attenuation limits with < 1.75 MV accelerator terminal voltage and ppm impurity levels were calculated to be 36S–/Cl– ~ 4 x 10^–16, 12C3–/Cl– ~ 1.2 x 10^–16, 90YF3–/SrF3– ~ 10^–15 and 90ZrF3–/SrF3– ~ 10^–16. Using 1.75 MV, four 36Cl reference standards in the range 4 x 10^–13 < 36Cl/Cl < 4 x 10^–11 were analyzed with 8 mTorr NO2. The measured 36Cl/Cl ratios plotted very well against the accepted values. A sample impurity content S/Cl < 6 x 10^–5 was measured and a background level of 36S–/Cl < 9 x 10^–15 was determined. Useful currents of a wide variety of anions are produced in AMS sputter sources and molecules can be identified relatively unambiguously by stripping fragments from tandem accelerators. Reactions involving YF3–, ZrF3–, S– and SO– + NO2 in the ISA analyzed by AMS are described, and some interesting reactants are identified.