479 resultados para Resíduos agrícolas


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This work develops a methodology (using the degree-days concept and linear regression), to forecast the duration of phenological phases in crops. An experiment was conducted in the greenhouse with three cultivars of cowpea (Vigna unguiculata (L.) Walp.), cv. Califórnia-781, Tvx 5058-09C and IT 81D-1032. The methodology was based on the relative thermal efficiency rate, determined for each species or cv. The results show that the proposed methodology may be a good alternative in works involving crops, especially because it does not require the repetition of the experiments.

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In order to study the effect of gypsum, lime and the mixture of lime-gypsum, associated with syrup in the agricultural and industrial production and in the rooting of sugar-cane (Saccharum spp.), var. IAC 58-480, one experiment was carried out in soil Terra Roxa Estrutura. Sugar-cane was planted in November 1986, and the cane-plant harvesting in September 1988. Three successive harvests were collected.The experiment was set in a randomized block design with seven treatments and four replications .The treatments were: T1 - 1.2 ton/ha of lime; T2 - 0.8 ton/ha of lime + 0.4 ton/ha of gypsum; T3 - 0.6 ton/ha of lime + 0.6 ton/ha of gypsum; T4 - 0.4 ton/ha of lime + 0.8 ton/ha of gypsum; T5 - 1.2 ton/ha of gypsum; T6 - 2.4 ton/ha of gypsum; T7 - control. Syrup was applied at the amount of 45 m3/ha.In September 1990, after the third harvesting, the second application of the treatments was made, the gypsum being applied in amounts four times greater than those of that put into practice at the planting. During harvest, the following parameters were evaluated: number, length and average diameter of the stalks; yield; and probable sugar and theoretical alcohol production per hectare.The results showed that the second application of the treatments recuperated the crop. Greater yields were achieved when the gypsum was associated with lime or syrup.

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This paper supplies a revision about the main techniques of extraction, clean-up and pre-concentration of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) in water and soil samples, as well as chromatographic methods and immune assays for its identification and quantification.

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The use of oxygen to enrich the combustion air can be an attractive technique to increase capacity of an incinerator originally designed to operate with air. If incinerator parameters such as operation temperature, turbulence level and residence time are fixed for a certain fuel supply rate, it is possible to increase the residue consumption rate using enriched air. This paper presents the thermal analysis for operation with enriched air of an aqueous residue experimental incinerator. The auxiliary fuel was diesel oil. The theoretical results showed that there is a considerable increase in the incineration ratio up to approximately 50 % of O 2 in the oxidiser. The tendency was confirmed experimentally. Thermal analysis was demonstrated to be an important tool to predict possible incinerator capacity increase.

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The use of phosphate fertilizers and amendments in sugar cane crops may increase the concentration of some elements in soils, from where they would become available for plants (principally in acid soils) and transferred to me human food chain. This paper reports the transference of heavy metals (Cd, Cr, Cu, Ni, Pb and Zn), fluorine and radionuclides ( 238U, 234U, 226Ra, 232Th and 40K) from phosphate fertilizers and amendments to agricultural soils at Corumbatal River basin (SP). The products utilized and colleted in sugar cane crops at Corumbatai River basin are: phosphate fertilizers NPK 5:25:25 (two samples), limestones (three samples), phosphogypsum (two samples) and KCl (two samples). The heavy metals were determined by atomic absorption spectrometry (AAS), fluorine by potentiometry and radionuclides by alpha and gamma spectrometry. Heavy metals (17.8, 31.2, 75.2, 69.5, 138.8, 114.9 and 342.9 g/ha of Cd, Cr, Cu, Ni, Pb, Zn and F, respectively) and radionuclides (0.47, 0.16, 0.17 and 6.33 Bq/kg of soil to 238U, 226Ra, 232Th and 40K, respectively) incorporated in phosphate fertilizers and amendments are annually added in the sugar cane crops, but if utilized in accordance with the recommended rates, they do not raise the concentration levels in soils up to hazards values.

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This work studied alterations of physical properties of a distroferric red nitosol due to millet (Pennisetum americanum) covering, with or without liming, in a no-tillage system during the agricultural years of 1999/2000 and 2000/2001, using soybean and corn as culture succession. 6m×10m plots, with and without millet as vegetal covering, received only one initial superficial application of limestone, 3.1 t ha-1 in the first half of each plot in order to obtain 70% base saturation (V), after the desiccation of the millet. Some physical properties as soil density, aggregate stability, > 2 mm aggregate proportion, macro and micro porosity were analyzed whereas the chemical analysis determined Ca and Mg macro nutrients, organic matter, soil pH and H+Al. Millet vegetal residues and surface liming did not alter soil density nor the average weight diameter (AWD), > 2 mm aggregate, soil macro porosity and organic matter content, twenty-four months after the no-tillage system implantation for studied experimental conditions. Soil micro porosity was significantly affected in layers deeper than 0.20 m, in treatment with millet and limestone. Calcium, magnesium and H + Al contents and the soil pH values suffered significant alterations in superficial layer, between 0-0.05 m.

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In this work results are presented of laboratory tests aiming to evaluate the possibility of using concrete wastes in manufactured soil-cement pressed bricks. Tests of characterization of used soil of the composite of this soil with concrete wastes and of the mixtures of soil cement made with this composite were evaluated. According to results of tests carried out with cylindrical specimens and with soil cement pressed bricks, it was verified that the addition of the concrete wastes improved soil cement mechanical properties, favoring the a reduction of the cement consumption, obtaining pressed bricks with a better quality.

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Composting has been a viable and efficient alternative treatment to agroindustrial waste. This experiment was installed with the objective of analyzing the process of composting for slaughterhouse waste. Twelve piles of composting were prepared, using slaughterhouse waste, wheat straw and wood sawdust. The process was evaluated by daily temperature monitoring, observations of the occurrence of undesirable parameters (bad smell and/or ammoniacal smell, grease formation and presence of grubs and flies), as well as the capacity of recycling nutrients. The undesirable parameters were observed, on average, for the first five days after pile building; the temperatures increased, reaching 70 °C; chemical composition of compost showed relevant contents of macro and micronutrients, a high recycling potential. Utilization of impermeable floor and roof are recommended during the composting. The turning frequency used (15 days after pile building followed by turning) was adequate. The best relation of weight was 7.2 kg of waste for each kg of straw and 16.6 kg of waste for each kg of sawdust.

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The incentive for consumption and production in large quantity in modern society generates enormous amounts of urban solid residues in the form of municipal solid waste (MSW). With the intention of reducing these residues of the municipal waste tips and to generate energy, briquettes with mixtures of MSW and residues of Eucalyptus grandis were produced. The briquettes were manufactured with 0, 5, 10, 15, 20 and 25% of MSW in the mixture with wood waste and 12% of moisture content. The analyzed parameters used to choose the best treatments were combustion analysis versus ash content, mechanical strength and energy content. The briquettes up to 10% of MSW showed low resistance, and above 15% showed large increase in ash content. Therefore, the treatment that fulfilled the requirements for combustion versus ash content and mechanical resistance was of at least 15% of MSW, since the source of the ash is unidentified. Considering the net energy content, the best treatment was 25% of MSW, with 17,175 kJ kg-1. Nevertheless, it is strongly advised that further studies related to gas emissions are necessary.

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The residues generation is a quite serious problem in several industrial areas and also in the lumbering area. The search for the elimination or reduction of the volume of generated residues is endless, however limited, resulting in the search for a proper destination or better use, instead of simply burning it. A lot of uses and services are commonly proposed, but with low aggregated value to the residue. This work shows the usage viability of different discarded residues and wood composites in the production of an electric guitar. Cupiúba, ipê and jatobá residues have been used besides wood composites of pinus. The residues and wood composites have shown appropriate resistance, surfacing quality and design terms, and could be used to substitute the traditionally wood used in the production of the instrument as well as in other products of similar characteristics and with larger aggregated value.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The objective of this paper was to review data on residues of medical products in aquatic environments and at wastewater treatment plants. Secondarily the paper presents a discussion about the need for a good management of drugs residues and effluents generated by this sector. Bringing the evidences of environmental possible damages reported by ecotoxicity data on the effects of fluoxetine to Vibrio fischeri and H. azteca, aquatic organisms daily exposed to environmental contaminants. From the results we observed that 0.3 mg.l-1 of fluoxetine hidrochloride induced lethality to H. azteca and 30 mg.l-1 reduced the luminescence of Vibrio fischeri. This assay evidenced higher toxicity when we used the generic product.

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Several factors have contributed to the increase the world production of urban solid waste, resulting in difficulties to the correct management and the final environmentally appropriate disposal, in addition to causing serious socio-economic, environmental, and public health troubles. The soil and groundwater contamination by leachate in waste disposal sites is almost always present, leveraging the emergence and/or adaptation of methodologies for environmental assessment of these areas. The geophysical methods, especially the electrical resistivity method, are fast, reliable and low-cost alternative for this purpose. This paper reports the methodology adopted for the temporal monitoring of the plume of contamination of controlled landfill in the municipality of Rio Claro (SP). Electrical resistivity data were obtained in 1999 and 2008, by the resistivity method, using the techniques of vertical electrical sounding and electrical profile. In both years, similar tests were carried out in the same locations within the disposal area. The results indicated that the plume of contamination has resistivity values less than or equal to 50 ohm.m and moves guided by 2 flows: the main, to the southeast, and the secondary, to the west. Relatively to the first series of tests in 1999, the plume of contamination was higher and deeper in 2008, contrary to what was expected for a landfill deactivated for at least 10 years.

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Taking into account the current context about environmental concern, the main purposes of this research were to develop and apply indicators in order to evaluate waste residues management in airports. As a result, 17 indicators related to generation, storage, transportation, collection, and solid waste disposal were created. These were applied in Viracopos International Airport, in Campinas, São Paulo State, Brazil. The results obtained in the study had a 2.9 performance, in a scale from one to five, characterized as regular. Posteriorly, the main weaknesses in waste residues management were analyzed in such Airport, as well as good practices and solutions were identifed. The highlighted management strategies suggested were the adjustment of areas for waste storage, recycling, and residues composting.