992 resultados para Abundância de aves
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Hydrogen sulphide is one of the most toxic and corrosive compound present in swine-derived biogas streams.In this study, afield scale biotrickling filter for the removal of hydrogen sulfide was investigated.A Biofilter packed with supporting biofilm materials was fed continuously with a proprietary nutrient solution and operatedfor over 73days. The system has been operating with a H2S inlet concentrations ranging from 1,000to 3,000 ppm.Significant removal efficiencies >95% was demonstrated. pH of the stock feeding solution decreased from 6.2 to as low as 3.5within couple days.The resulting drop in pH provided circumstantial evidence to support biological H2 Soxidation to sulphuric acid by sulfide-oxidizers. Sulfur precipitation was also observed to occur. The results suggested that H2S removal from biogas stream can be efficiently achieved using portable, low cost and maintenance free biotrickling filters.
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The effects of swine wastewater-derived biogas on microalgae productivity were determined. Experiments were conducted in a closed photobioreactor containing digestate effluent as culturing media and biogas in the headspaceas source of CO2. Experiments were carried out under mixothrophic and autothrophic conditions. Results showed that autotrophic growth rate (0.6 d-1)was twofoldfaster than mixotrophic. Frequent reinjections of biogas containing up to 2,000 ppm of hydrogen sulfide was not inhibitory to microalgae growth. The rapid removal of H2S in the system suggests photobioreactors can be an interesting alternative to biogas purification. A model to estimate microalgae productivity based on the amount of available CO2, inorganic and organic carbon was developedand showed good data fit correlation (r²= 0.99).
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Phycoremediation of swine wastewaters has been widely reported as an attractive tertiary treatment system, that effectively removes the excessive nutrient loadswhilst offering a valuable source of feedstock biomass. Digestate from an upflow anaerobic sludge blanket (UASB, 6%v/v) and a nitrification reactor (NR; 50% v/v) were used as culturing media to microalgae. Experiments were carried out in lab scale photobioreactors (PBRs) using a consortia of Chlorella and Scenedesmus. Ammonia (44 to 90%) and phosphorus (77%) were efficiently removed from both effluents tested after 4 days. Microalgae biomass harvested from the UASB effluent showed 57, 34 and 1% of proteins, carbohydrates and lipids, respectively. Comparatively, the cellular composition of microalgae grown on NR effluent had lower protein (43%) but higher carbohydrate (42%) contents. Negligible difference in lipid fraction was observed independently of the effluents tested. The results suggest that the biomass harvested from phycoremediation of swine wastewaters can offer a valuable protein and carbohydrate feedstock for nutritional and biotechnological applications.
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2015
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use of additives (Mg/P and nitrification inhibitor dicyandiamide - DCD), on nitrous oxide emission during swine slurry composting. The experiment was run in duplicate; the gas was monitored for 30 days in different treatments (control, DCD, Mg/P and DCD + Mg/P). Nitrous oxide emissions rate (mg of N2O-N.day-1) and the accumulated emissions were calculated to compare the treatments. Results has shown that emissions of N-N2O were reduced by approximately 70, 46 and 96% through the additions of DCD, MgCl2.6H2O + H3PO4 and both additives, respectively, compared to the control. Keywords Composting; swine slurry; additives; nitrous
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O aumento na demanda de proteína animal e o aumento da população mundial levaram a 8 produção animal a obter o máximo de rendimento. Sob essas circunstâncias, a produção animal tornou-se 9 mais concentrada e controlada, o que resultou no confinamento dos animais. Desde que mais atenção foi 10 dada a fatores econômicos e rendimento por animal, o bem-estar e comportamento animal foi negligenciado. 11 Contudo, hoje em dia, o bem-estar animal está ganhando mais importância devido à pressão dos 12 consumidores e grandes mercados. Isso não necessariamente significa que fornecer boas práticas de manejo 13 aos animais irá melhorar bem-estar, pois alguns animais podem apresentar distresse mesmo sob boas 14 condições de ambiente . Contudo, a questão antes de qualquer tomada de decisão de investimentos em bem-15 estar animal deveria ser quanto é perdido quando o bem-estar animal é pobre, ao invés de quanto pode ser 16 ganho com os investimentos em bem-estar animal, ou simplesmente fazer isso porque é melhor para os 17 animais. Portanto, uma vez que o bem-estar animal representa um papel importante nas perdas durante a 18 produção, a cadeia produtora de carne deve adaptar-se para mudanças nas regras de bem-estar animal, 19 regulamentos e boas práticas de manejo pré-abate. Nesse artigo de revisão, o bem-estar animal é discutido 20 como uma alternativa para agregar valor melhorar a qualidade da carne suína.
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2015
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2015
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2015
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2016
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2016
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2016
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2016
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Dissertação apresentada para cumprimento dos requisitos necessários à obtenção grau de Mestre em Arqueologia
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Em um inquérito entomológico realizado em 2000, na zona periurbana do município de Dom Pedro-MA, pretendia-se estimar a abundância de Lutzomyia longipalpis, por conta da ocorrência de um óbito suspeito de calazar. Entretanto, constatou-se que do total de 2.961 flebótomos capturados no peridomicílio, 82,4% (2.440 espécimes) eram de Lutzomyia whitmani. Esta associação vem determinando um novo padrão de transmissão da leishmaniose cutânea (o urbano), como vem acontecendo com o calazar nordestino.