Gaseous ammonia emissions from livestock production are a well known source of anthropogenic ammonia emissions and have been the subject of numerous studies in Western Europe and in the United States of America. They are deemed responsible for the acidification of ecosystems. Furthermore, ammonia emissions from intensive livestock operations located in the vicinity of major cities induce favourable conditions for smog formation. Ammonia volatilization from manure also reduces its effectiveness as a fertilizer by reducing its nitrogen content, an important nutrient for plant growth. Certain technologies and structures exist to cover manure storage tanks in order to limit these ammonia losses to the atmosphere. Very few studies have been done in Canada where climate and manure management practices differ widely from those in Western Europe and in the United States of America. In this project, a measurement campaign was financed by Agriculture and Agrifood Canada on four commercial livestock production infrastructure to begin the development of national ammonia inventory. Commercial dairy and swine manure storages covered by floating geomembranes were monitored for periods exceeding six months in the Eastern Townships of Quebec. The swine manure storage emitted negligible amounts of ammonia, from 5.9 ?10[superscript -3] to 0.14 [micro]g? m[superscript -2] . s[superscript -1] over the summer time. The dairy manure storage emitted more substantial amounts of ammonia when the manure surface was frozen in winter, from 1.9 to 16 [micro]g. m[superscript -2] ? s[superscript -1], then when unfrozen, 93 to 166 [micro]g? m[superscript -2] ? s[supercript -1]. A structural difference in the covering technology at the dairy manure storage rendered it less airtight than the swine manure storage. Therefore, the efficiency of a cover to limit ammonia emissions from manure is function of its air tightness. Ammonia emission rates from two tie-stall commercial dairy buildings were also monitored in the Eastern Townships of Quebec. Ammonia emission measurements done at building A during winter 2007 ranged from 3.77 to 6.80 g ? day[superscript -1] ? animal[superscript -1] while those performed at building B during summer 2007 were higher and ranged from 11.33 to 18.20 g ? day[superscript -1] ? animal[superscript -1]. These values fall within the wide range of those published for Western Europe and the United States of America. However, unlike studies completed in Europe using similar procedures, the methods used to measure gaseous ammonia concentrations and building ventilation flow rates in this study were validated in controlled environments.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Composting of pig slurry (DLS) is an important strategy to mitigate the environmental damage of intensive pig farms. Despite being a promising strategy, one of the problems from composting is still the losses of nitrogen (N) by volatilization of ammonia (NH3). Acidification of DLS before to addition to the piles, reducing the pH and thus, the piles, may be a possibility to circumvent this problem. However, little is known about the effect of acidification of DLS, not only on emissions of (NH3) as with respect to emissions of greenhouse gases (GEE) (CO2, CH4 e N2O) during the process, especially in automated systems where the addition of manure and mixing of piles are frequent. This study was conducted with the objective of evaluating the effect of acidification of pig slurry on ammonia and greenhouse gases emissions during an automated composting process. The study was conducted at the Federal University of Santa Maria, RS, during 154 days in compost piles containing the mixture of wood shavings and sawdust as substrate, with weekly additions of DLS, followed by two revolving piles during the first 106 days. Between 107 and 154 days were made only weekly turnings piles. Two treatments were tested, one with manure acidification with H3PO4 to pH around 6.0 and another without acidification. The evaluation of emissions of NH3 was carried out in semi-open static chambers, while the GEE was performed in static chambers. The pH of DLS was reduced on average 0.87 units with acidification compared to the original values and the average value of all applications was 5.84. In compost piles, the pH decreased from 8.11 to 6.72 on average during all period of the experiment. The concentrations of NH4+ at the end of the experiment were, on an average of two evaluated layers, 102.98 mg kg-1 in the pile without acidification and 398.81 mg kg-1 in the pile with acidification, while the levels of NO3- were 13.37 mg kg-1 in the pile without acidification and 1371.04 mg kg-1 in the pile with acidification. The cumulative emission of NH3 in the treatment with acidification was 32.6 g m-2, 70% lower than the treatment without acidification (107.8 g m-2). Acidification of DLS also reduced the cumulative CO2 emissions to the atmosphere of 91.65 kg m-2 to 69.05 kg m-2 (25%) and the CH4 of 639.97 g m-2 to 227.13 g m-2 (65%). On the other hand, acidification of DLS at the time of addition to the substrate increased the cumulative emission of N2O by 30.4 g N-N2O m-2 (130%) at 154 days of composting. / A compostagem de dejetos líquidos de suínos (DLS) é uma importante estratégia para mitigar o passivo ambiental da suinocultura intensiva. Apesar de ser uma estratégia promissora, um dos problemas decorrentes da compostagem são, ainda, as perdas de nitrogênio (N) por volatilização de amônia (NH3). A acidificação dos DLS previamente a adição às pilhas, reduzindo seu pH e, consequentemente, das pilhas, pode ser uma possibilidade para contornar esse problema. Todavia, pouco se conhece sobre o efeito da acidificação dos DLS, não somente sobre as emissões de NH3 como no que tange às emissões de gases de efeito estufa (GEE) (CO2, CH4 e N2O) durante o processo, sobretudo, em sistemas automatizados, onde a adição de dejetos e o revolvimento das pilhas são frequentes. Esse trabalho foi conduzido com o objetivo de avaliar o efeito da acidificação de dejetos líquidos de suínos sobre as emissões de amônia e gases de efeito estufa durante um processo de compostagem automatizada. O trabalho foi conduzido na Universidade Federal de Santa Maria, RS, durante 154 dias, em pilhas de compostagem contendo a mistura de maravalha e serragem como substrato, com adições semanais de DLS, seguidas de dois revolvimentos das pilhas durante os primeiros 106 dias. No período entre 107 e 154 dias foram efetuados apenas revolvimentos semanais das pilhas. Foram testados dois tratamentos, sendo um com acidificação dos dejetos com H3PO4 até pH próximo a 6,0 e outro sem acidificação. A avaliação das emissões de NH3 foi realizada em câmaras estáticas semi-abertas, enquanto a de GEE foi realizada em câmaras estáticas. O pH dos DLS foi reduzido em média 0,87 unidades com a acidificação em relação aos valores originais, sendo o valor médio de todas as aplicações de 5,84. Nas pilhas de compostagem, o pH reduziu de 8,11 para 6,72 na média de todo período de condução do experimento. Os teores de NH4+ ao final do experimento foram, na média das duas camadas avaliadas, de 102,98 mg kg-1 na pilha sem acidificação e 398,81 mg kg-1 na pilha com acidificação, enquanto os teores de NO3- foram de 13,37 mg kg-1 na pilha sem acidificação e 1371,04 mg kg-1 na pilha com acidificação. A emissão acumulada de NH3 no tratamento com acidificação foi de 32,6 g m-2, 70% inferior ao tratamento sem acidificação (107,8 g m-2). A acidificação dos DLS reduziu, também, as emissões acumuladas de CO2 para a atmosfera de 91,65 kg m-2 para 69,05 kg m-2 (25%) e CH4 de 639,97 g m-2 para 227,13 g m-2 (65%). Por outro lado, a acidificação dos DLS no momento da sua adição ao substrato aumentou a emissão acumulada de N2O em 30,4 g N-N2O m-2 (130%) em 154 dias de compostagem.

Made available in DSpace on 2016-08-19T12:56:35Z (GMT). No. of bitstreams: 1 CASSIO DA SILVA DIAS.pdf: 1841610 bytes, checksum: 19960efa8e582ace78afd42034c3916a (MD5) Previous issue date: 2010-11-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In nature babassu oil can be applied as fuel in diesel engines. However, such practice is limited by its high viscosity and gum formation tendency. Conversely, vegetal oil-based microemulsions often have appropriated combustion and physicochemical properties. In such context, this work aims to evaluate microemulsions from vegetal oil, hydrated alcohol and fusel oil as an alternative fuel. Thus, the babassu chemical properties were determined by several analyses and its miscibility pattern was evaluated by means of phase diagrams. Based on such study, were selected microemulsion with high oil content. Among them, the 60% oil-based ternary system has presented desired characteristics, being evaluated as pure or binary diesel blended fuels. The combustion efficiency, for all samples, was evaluated according to fuel consumption, gaseous exhaust emission. In general, all microemulsified systems has presented low viscosities, being inferior to the initial oil and equivalent to diesel. Furthermore, it was observed a significant reduction of the gaseous releases for B5 microemulsion blend. / A utilização do óleo de babaçu in natura em motores do ciclo diesel é limitada, tendo em vista que sua alta viscosidade pode ocasionar a formação de gomas e entupimento dos bicos injetores do motor. Entretanto, a obtenção de microemulsões a partir do óleo vegetal, álcool hidratado e óleo fúsel constitui uma alternativa para redução da viscosidade do sistema, apresentando vantagens nos aspectos sociais, econômicos e ambientais. O objetivo desse trabalho é a obtenção de microemulsões combustíveis. Na primeira etapa foram avaliados os parâmetros físico-químicos do óleo de babaçu, sendo então, construído um diagrama de fases a partir dos componentes formadores das microemulsões. Posteriormente, fez-se a seleção da região de microemulsão dos sistemas com maior proporção de óleo vegetal nos quais foram realizados ensaios físico-químicos de caracterização, sendo escolhido um sistema com proporção de 60% do óleo vegetal para ser testado puro e misturado ao diesel em um motor. A eficiência da combustão das microemulsões e de suas misturas binárias com o diesel no motor, baseou-se na quantificação do consumo, vazão dos gases e emissões de CO, CO2 e NOx. Os sistemas microemulsionados apresentaram uma redução significativa da viscosidade, quando comparado ao óleo de babaçu degomado, ficando-as semelhantes ao diesel e atingindo valores equivalentes aos padrões de comercialização. Houve uma melhora nos índices de emissões gasosas para as misturas das microemulsões com o B5.

Irish agriculture is becoming increasingly regulated, with restrictions on fertiliser application rates and stocking rates to reduce nitrate (NO₀⁻) leaching losses. However these regulations have been, to date, based on minimal field research. The purpose of this study was to determine the actual leaching losses of nitrate from Irish dairy pasture at a range of stocking rates, and to investigate the effectiveness of the nitrification inhibitor DCD at reducing nitrate leaching losses where these are deemed excessive. In grazed pastures, a major source of leached nitrate is the urine patch, where a high rate of N is applied in one application. This trial recorded the losses from urine and non-urine areas of pasture separately. Nitrate leaching losses from three soils were recorded using lysimeters at Johnstown Castle, Co. Wexford, over two years. Total nitrate losses were higher from the freely drained Clonakilty and Elton soils than from the heavy Rathangan soil. Mean nitrate losses from urine patches ranged from 16 - 233 kg nitrate-N / ha⁻¹, and were reduced by up to 53% when DCD was applied. DCD also reduced peak and mean nitrate-N concentrations in many cases. In addition, DCD halved the nitrous oxide (N₂O) emission factor on the Rathangan soil, caused increases in pasture N content, and increased herbage yield in some treatments. The distribution of urine patches under dairy grazing was recorded using GPS at Kilworth, Co. Cork. Cows were also found to deposit 0.359 urine patches per grazing hour. A model was produced to predict field-scale nitrate leaching losses from dairy pasture at a range of stocking rates. At 2.94 cows per hectare, the highest stocking rate, annual field N loss was below 34 kg nitrate-N ha⁻¹, mean drainage N concentrations were below 5.65 mg nitrate-N L⁻¹ (the EU drinking water guideline value), and the worst-case-scenario autumn peak concentration did not exceed 21.55 mg nitrate-N L⁻¹ (above the EU Maximum Allowable Concentration (MAC) but below the World Health Organisation (WHO) drinking water limit). DCD reduced total annual field N loss by 21% (a conservative estimate), and also reduced mean and peak nitrate concentrations. Provided fertiliser application rates are at or below 291 kg N ha⁻¹, and based on current legislative values for drinking water quality, this trial does not support any blanket restrictions on the stocking rate of Irish dairy farms. However where particularly high water quality is required, DCD shows potential as a useful tool to achieve low nitrate concentrations.