977 resultados para High organic


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The region of Aracá River (Middle and Upper Rio Negro-AM) has peculiar characteristics, having soils with atypical profile and high organic matter contents in great deep. The levels of aluminum and iron in the soil samples increased as a function of depth and concentrations of mercury ranged from 0.097 to 0.964 µg g-1. Statistical analysis showed the degree of similarity between soil samples collected. The highest concentrations of mercury in soil samples are directly related to soil higher content of organic matter, directly influencing the fate and bioavailability of mercury species to the environment.

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The cassava processing industry generates wastewater named manipueira with a high organic content. Although considered a pollutant, manipueira can be used as substrate for fermentative processes including the cultivation of Geotrichum fragrans. This aerobic microorganism isolated from cassava wastewater has cyanide resistant respiration. Under cassava wastewater cultivation, G. fragrans produced fruit aroma volatile compounds. This study evaluated volatile compounds produced by G. fragrans in cassava liquid waste. The waste had a sugar composition composed of dextrin (2.6%), maltose (1.4%), sucrose (32.1%), glucose (38.3%), and fructose (25.6%). The average value of total sugars was 58.2 g l(-1), composed of 38.0 g l(-1) reducing and 20.2 g l(-1) non-reducing sugars. The chemical oxygen demand (COD) average value was 60 000 mg l(-1). G. fragrans used sugars (fructose and glucose) for energy generation reducing the COD value of the cassava wastewater by 40%. Biomass production of G. fragrans cultivated for 12 h in natural cassava liquid waste was 12.8 g l(-)1. The volatile compounds identified in the cassava liquid waste after 72 h cultivation were: 1-butanol, 3-methyl 1-butanol (isoamylic alcohol), 2-methyl 1-butanol, 1-3 butanodiol and phenylethanol; ethyl acetate, ethyl propionate, 2-methyl ethyl propionate and 2-methyl propanoic. The effect of substrate supplementation with glucose (50 g l(-1)), fructose (50 g l(-1)) and aqueous yeast extract (200 ml l(-1)) did not affect the qualitative and quantitative profiles of volatile compounds. These results indicate that the carbon (C) source utilized by microorganism was glucose or fructose, while nitrogen (N) supplementation was not necessary because the agent did not exhaust all the nitrogen of the wastewater. (C) 2003 Elsevier B.V. Ltd. All rights reserved.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Sewage sludge, waste with high organic matter content and rapid decomposition, combined with sawdust, rich in carbon and slow decomposition, are suitable components for the study of degraded areas. In order to test the interactions of these residues in the recovery of a degraded soil in Selvíria - MS, four doses of sewage sludge (0, 8, 16 and 24 t ha -1, dry basis ) and four doses of sawdust particles (0, 8, 16 and 24 t ha-1, dry basis ) were tested in February 2009, in a completely randomized block design (4 × 4 + 1 factorial), with four replications. As indicators of the effects, the penetration resistance, gravimetric moisture and soil bulk density (0-0.10, 0.10-0.20; 0.20-0.40 m) were used. Significant effects were observed for the factors (sewage sludge and sawdust) and control treatment for penetration resistance in the soil depths studied, for gravimetric moisture in the intermediate layer and for the soil density in the surface and intermediate layers. Considering the type of soil and the short period of study (24 months), the use of organic wastes presented improvement in physical properties of soil in relation to control. However, it is necessary to study them for a longer period.

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Pós-graduação em Engenharia e Ciência de Alimentos - IBILCE

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The amount of waste generated by industries has increased gradually in recent years. The proper disposal of residues has been an area of study of many researchers. Several organic compounds are considered potential contaminants of natural waters due to their high toxicity, difficult natural degradation and long persistence in the environment. Ways of recovery and reutilization as well as concepts that minimize the generation of wastes have been increasing widely. Organometallic compound of pyrazine carboxylic acid has proven to be of great interest in many areas. Herein, we studied the use of pyrazine tetracarboxylic acid ligand for complex formation with iron (Fe). The binder (C 8H4N2O8) was synthetized with the addition of Fe (complex) and tested as a catalyst in oxidation reactions of the organic model compound methylene blue (MB). Tetramethyl pyrazine was used in the synthesis, which was oxidized with potassium permanganate in order to form the ligand. The ligand (C 8H4N2O8) was then characterized to validate its formation. For the complex solution, it was used (C 8H4N2O8) and Fe (NO3)3.9H2O 0,01molL-1. After preliminary tests, it was found that the best ratio of Fe and the ligand was 2: 1. Through the oxidation tests, it could be seen that the complex has great potential for the degradation of different concentrations of MB. During only 20 minutes of reaction, approximately 60% of MB 500 mgL -1 was oxidized. The use of the complex was found to be an attractive alternative for oxidation of effluents with high organic compounds levels and contributes to the minimization of organic contaminants hazards in the environment.

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Pós-graduação em Serviço Social - FCHS

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Pós-graduação em Agronomia (Energia na Agricultura) - FCA

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Ethanol, the main automotive biofuel, has its production based on the fermentation of sugars found in biological materials and on the distillation of the alcoholic media formed during the fermentative process. Stillage is the main residue from ethanol production, containing a high organic loading in addition to acidic and corrosive characteristics. Considering the available technologies to treat stillage, we highlight anaerobic digestion, which allows the reduction of the impacts associated to pollutants loading of this effluent and the generation of energy from the methane gas produced in the process. Based on the high treatment efficiency usually associated to the anaerobic process, this work aimed to assess whether anaerobic systems applied to the treatment of stillage are energetically self-sufficient. First we evaluated the energy recovery capacity in an anaerobic reactor applied to the treatment of stillage resulting from corn-to-ethanol processing. The results indicated the great influence that a correct selection of electrical equipment and their respective operating periods have on the net energy balance of the anaerobic treatment. The high energy consumption of the heater would not allow the system to achieve a positive net energy balance – the maximum energy recovery would reach only 0.68% of the consumption. However, the replacement of the mixture equipment would result in energy gains ranging from 8.5 to 967.9% of the consumption. In this work we also assessed the efficiency of methane yields for a few studies and the correlation between some parameters of the anaerobic process. With respect to the methane yield, we noted that mesophilic systems tend to be more advantageous than the thermophilic ones (efficiency of 76.45 ± 22.51% vs. 69.40 ± 30.36%). Considering the study... (Complete abstract click electronic access below)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Pós-graduação em Agronomia (Ciência do Solo) - FCAV

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The swine culture potentially generates waste with high organic load and pollutants, being responsible for the spread of pathogens, contamination of rivers, groundwater and soils, besides it produces foul odors and emit greenhouse gases. However, the high amount of organic matter, which expresses the amount of pollutant load, reflects the energetic potential of these wastes used as raw material in biogas generation through technology of digesters. The properly use of theses digesters provides the production of clean energy and promotes the conservation of the environment. The economic viability of the implantation of an Indian model digester on a small swine farm was verified based on the value from initial investments of deployment, maintenance costs, depreciation, and on the interest and revenues arising from the system. Besides, the amount of biogas produced daily and the average consumption of biogas by the most common used devices such as refrigerator, stove, water heater, and generator of electricity was calculated.. For a backdrop of 10 years, the results of economic indicators NPV of BRL 57,598.95, IRR of 48.38%, Simple Payback of 2.06 years, and Discounted Payback of 2.3 years, demonstrated a favorable outlook for the use of this technology, with the possibility to generate economic, social and environmental benefits.