992 resultados para RADIOACTIVE WASTE PROCESSING


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Banana is an agricultural product of great economic importance for various developing countries. The relationship between moisture content and water activity provides useful information for the processing and storage of banana waste. The water activity and moisture content of three banana (Mussa spp. Haploid AAB cv. Nanica) waste items were analyzed to determine the desorption isotherms at six different temperatures (20, 30, 40, 50, 60 and 70°C). The desorption isotherms of the peel, pedicel and pulp of overripe bananas were determined in wide ranges of moisture content (0.001-6.360 kg kg-1 d.b.) and water activity (0.02-0.907). The theoretical GAB model was used for modelling the desorption isotherms. An analytical solution of the Clausius-Clapeyron equation was proposed to compute the isosteric heat of sorption, the differential entropy and Gibbs' free energy by way of the GAB model when the effect of temperature on the hygroscopic equilibrium was considered. © 2012 de Gruyter. All rights reserved.

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Agroindustrial by-products and residues from treatment of sewage sludge have been recently recycled as soil amendments. This study was aimed at assessing toxic potential of biosolid, obtained from a sewage treatment plant (STP), vinasse, a by-product of the sugar cane industry, and a combination of both residues using Allium cepa assay. Bioprocessing of these samples by a terrestrial invertebrate (diplopod Rhinocricus padbergi) was also examined. Bioassay assembly followed standards of the Brazilian legislation for disposal of these residues. After adding residues, 20 diplopods were placed in each terrarium, where they remained for 30 days. Chemical analysis and the A. cepa assay were conducted before and after bioprocessing by diplopods. At the end of the bioassay, there was a decrease in arsenic and mercury. For the remaining metals, accumulation and/or bioavailability varied in all samples but suggested bioprocessing by animals. The A. cepa test revealed genotoxic effects characterized by different chromosome aberrations. Micronuclei and chromosome breaks on meristematic cells and F1 cells with micronuclei were examined to assess mutagenicity of samples. After 30 days, the genotoxic effects were significantly reduced in the soil + biosolid and soil + biosolid + vinasse groups as well as the mutagenic effects in the soil + biosolid + vinasse group. Similar to vermicomposting, bioprocessing of residues by diplopods can be a feasible alternative and used prior to application in crops to improve degraded soils and/or city dumps. Based on our findings, further studies are needed to adequately dispose of these residues in the environment. © 2013 Springer Science+Business Media Dordrecht.

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The potential of natural and heat-treated Macauba palm cake as adsorbent for the removal of Methylene Blue (MB) and Congo Red (CR) from solution has been investigated. Equilibrium adsorption was attained in <7 h and the process was favored at pH 5.0 for MB and pH 6.5 for CR with an adsorbent (g):adsorbate (mL) ratio of 1:200 and an initial concentration of adsorbate of 25 mg L−1. The maximum adsorption capacities of the natural and heat-treated materials were, respectively, 25.80 and 32.30 mg g−1 for MB, and 32.00 and 20.30 mg g−1 for CR. The isotherm model proposed by Sips represented most adequately the adsorption of MB and CR. The adsorptions of the dyes were best described in terms of a pseudo second-order reaction. Thermodynamic parameters such as ΔHo, ΔSo and ΔGo were calculated. The adsorption process was found to be endothermic and spontaneous. Macauba palm cake is adequate for the removal of waste dye from industrial effluents by virtue of its abundance, low cost and efficiency of adsorption.

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O objetivo deste trabalho foi realizar a caracterização físico-química e microbiológica do surimi obtido de resíduos da filetagem de piramutaba. Os resultados da caracterização físico-química dos resíduos e surimi foram: umidade (76,37 e 79,11%), lipídios totais (5,35 e 0,74%), proteínas (14,92 e 10,79%), cinzas (3,03 e 2,35%), pH (6,9 e 7,4), valor calórico (109,15 e 77,86 kcal.g-1) e atividade de água (ambos 0,98), respectivamente. Os resultados dos valores de bases voláteis totais foi de 7,29 mgN/100-1 g (resíduos) e carboidratos de 7,01% (surimi). Os valores de lipídios totais e proteínas foram reduzidos durante o preparo do surimi, provavelmente, devido a sucessivas lavagens durante o processamento. Os resíduos e o surimi foram analisados microbiologicamente estando em conformidade com os parâmetros exigidos. Os resultados mostraram que houve uma perda da cor vermelha (parâmetro a*) e amarela (parâmetro b*). Por outro lado, o parâmetro L* (luminosidade) aumentou após o processamento do surimi. Conclui-se que os resíduos de piramutaba podem ser empregados como matéria-prima de qualidade na elaboração de surimi e como fonte de nutrientes para a alimentação humana, constituindo-se também como uma alternativa para destino dos resíduos, antes lançados no ambiente.

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In this work, a method was developed for the application of red mud, an alkaline leaching waste, from a bauxite processing plant located in northern Brazil (Amazon region) as starting material for heavy clay products. Samples were prepared by pressing blends of red mud and clay, which were then fired at temperatures from 900 ºC to 1190 ºC. Characterization was carried out by chemical analysis, differential thermal analysis (DTA) and X-ray diffraction (XRD), and the following ceramic properties were evaluated: water absorption, linear shrinkage and flexural strength. In order to evaluate the Na+ stability in the dense ceramic, leaching tests were also carried out on the specimens after sintering process. Results indicated that samples with 50 and 70 wt% of red mud are proper for being used in the production of ceramic bodies, due to its excellent properties, mainly high mechanical resistance and low water absorption, showing thus, an option to minimizing the environmental impacts caused by the aluminum industry.

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Between 75% and 90% of the waste produced by health-care providers no risk or is "general" health-care waste, comparable to domestic waste. The remaining 10-25% of health-care waste is regarded as hazardous due to one or more of the following characteristics: it may contain infectious agents, sharps, toxic or hazardous chemicals or it may be radioactive. Infectious health-care waste, particularly sharps, has been responsible for most of the accidents reported in the literature. In this work the preliminary risks analysis (PRA) technique was used to evaluate practices in the handling of infectious health-care waste. Currently the PRA technique is being used to identify and to evaluate the potential for hazard of the activities, products, and services from facilities and industries. The system studied was a health-care establishment which has handling practices for infectious waste. Thirty-six procedures related to segregation, containment, internal collection, and storage operation were analyzed. The severity of the consequences of the failure (risk) that can occur from careless management of infectious health-care waste was classified into four categories: negligible, marginal, critical, and catastrophic. The results obtained in this study showed that events with critics consequences, about 80%, may occur during the implementation of the containment operation, suggesting the need to prioritize this operation. As a result of the methodology applied in this work, a flowchart the risk series was also obtained. In the flowchart the events that can occur as a consequence of a improper handling of infectious health-care waste, which can cause critical risks such as injuries from sharps and contamination (infection) from pathogenic microorganisms, are shown.

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The problem of proper disposal of solid waste generated in different industrial processes is one of worldwide environmental concerns nowadays. Thus, this study aimed to establish a new alternative for the disposal of two agro-industrial residues employing them to produce particleboard for different purposes in building construction. The focus was given to the reuse of the sugarcane bagasse (SB) originated during the processing of Saccharum officinarum for sugar and ethanol production, and bamboo stem leaves of Dendrocalamus giganteus(BB). For this, six particleboards were produced in the following compositions: with 100% SB, 75% SB + 25% BB, 50% SB+50% BB, 40% SB +60 BB, 25% SB+ 75% BB and 100% BB in the total mass of the composites. The particleboards physical characterization followed Brazilian Standard ABNT NBR 14810-3 to density, moisture content and water absorption. Results showed these raw materials are compatible to particleboard production.

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Vegetal origin agro-industrial wastes are seen as a problem since the beginning of the industrial processes; however, they are becoming attractive as raw material for numerous purposes such as active enzymes and in the molecule bioprospecting area. Moreover, it is difficult to understand what the studied residue is consisted of in studies on agro-industrial waste, since the wastes names and constituents may vary according to the used equipment, as for waste from orange and mango processing. Thus, defining a specific waste, including comparisons between botanical and industrial descriptions, can help in understanding studies about wastes. The current review sought to contextualize such a scenario by gathering definitions, relevant information and studies on agro-industrial wastes and by-products, international enzymes market, and recent studies on bioactive compounds. In this context, waste from orange and mango are interesting because of the expression of these fruits on the world market; moreover, the processing does not include steps that could disrupt these biomolecules.

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

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Radiometals play an important role in nuclear medicine as involved in diagnostic or therapeutic agents. In the present work the radiochemical aspects of production and processing of very promising radiometals of the third group of the periodic table, namely radiogallium and radiolanthanides are investigated. The 68Ge/68Ga generator (68Ge, T½ = 270.8 d) provides a cyclotron-independent source of positron-emitting 68Ga (T½ = 68 min), which can be used for coordinative labelling. However, for labelling of biomolecules via bifunctional chelators, particularly if legal aspects of production of radiopharmaceuticals are considered, 68Ga(III) as eluted initially needs to be pre-concentrated and purified. The first experimental chapter describes a system for simple and efficient handling of the 68Ge/68Ga generator eluates with a cation-exchange micro-chromatography column as the main component. Chemical purification and volume concentration of 68Ga(III) are carried out in hydrochloric acid – acetone media. Finally, generator produced 68Ga(III) is obtained with an excellent radiochemical and chemical purity in a minimised volume in a form applicable directly for the synthesis of 68Ga-labelled radiopharmaceuticals. For labelling with 68Ga(III), somatostatin analogue DOTA-octreotides (DOTATOC, DOTANOC) are used. 68Ga-DOTATOC and 68Ga-DOTANOC were successfully used to diagnose human somatostatin receptor-expressing tumours with PET/CT. Additionally, the proposed method was adapted for purification and medical utilisation of the cyclotron produced SPECT gallium radionuclide 67Ga(III). Second experimental chapter discusses a diagnostic radiolanthanide 140Nd, produced by irradiation of macro amounts of natural CeO2 and Pr2O3 in natCe(3He,xn)140Nd and 141Pr(p,2n)140Nd nuclear reactions, respectively. With this produced and processed 140Nd an efficient 140Nd/140Pr radionuclide generator system has been developed and evaluated. The principle of radiochemical separation of the mother and daughter radiolanthanides is based on physical-chemical transitions (hot-atom effects) of 140Pr following the electron capture process of 140Nd. The mother radionuclide 140Nd(III) is quantitatively absorbed on a solid phase matrix in the chemical form of 140Nd-DOTA-conjugated complexes, while daughter nuclide 140Pr is generated in an ionic species. With a very high elution yield and satisfactory chemical and radiolytical stability the system could able to provide the short-lived positron-emitting radiolanthanide 140Pr for PET investigations. In the third experimental chapter, analogously to physical-chemical transitions after the radioactive decay of 140Nd in 140Pr-DOTA, the rapture of the chemical bond between a radiolanthanide and the DOTA ligand, after the thermal neutron capture reaction (Szilard-Chalmers effect) was evaluated for production of the relevant radiolanthanides with high specific activity at TRIGA II Mainz nuclear reactor. The physical-chemical model was developed and first quantitative data are presented. As an example, 166Ho could be produced with a specific activity higher than its limiting value for TRIGA II Mainz, namely about 2 GBq/mg versus 0.9 GBq/mg. While free 166Ho(III) is produced in situ, it is not forming a 166Ho-DOTA complex and therefore can be separated from the inactive 165Ho-DOTA material. The analysis of the experimental data shows that radionuclides with half-life T½ < 64 h can be produced on TRIGA II Mainz nuclear reactor, with specific activity higher than any available at irradiation of simple targets e.g. oxides.

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Volatile amines are prominent indicators of food freshness, as they are produced during many microbiological food degradation processes. Monitoring and indicating the volatile amine concentration within the food package by intelligent packaging solutions might therefore be a simple yet powerful way to control food safety throughout the distribution chain.rnrnIn this context, this work aims to the formation of colourimetric amine sensing surfaces on different substrates, especially transparent PET packaging foil. The colour change of the deposited layers should ideally be discernible by the human eye to facilitate the determination by the end-user. rnrnDifferent tailored zinc(II) and chromium(III) metalloporphyrins have been used as chromophores for the colourimetric detection of volatile amines. A new concept to increase the porphyrins absorbance change upon exposure to amines is introduced. Moreover, the novel porphyrins’ processability during the deposition process is increased by their enhanced solubility in non-polar solvents.rnrnThe porphyrin chromophores have successfully been incorporated into polysiloxane matrices on different substrates via a dielectric barrier discharge enhanced chemical vapour deposition. This process allows the use of nitrogen as a cheap and abundant plasma gas, produces minor amounts of waste and by-products and can be easily introduced into (existing) roll-to-roll production lines. The formed hybrid sensing layers tightly incorporate the porphyrins and moreover form a porous structure to facilitate the amines diffusion to and interaction with the chromophores.rnrnThe work is completed with the thorough analysis of the porphyrins’ amine sensing performance in solution as well as in the hybrid coatings . To reveal the underlying interaction mechanisms, the experimental results are supported by DFT calculations. The deposited layers could be used for the detection of NEt3 concentrations below 10 ppm in the gas phase. Moreover, the coated foils have been tested in preliminary food storage experiments. rnrnThe mechanistic investigations on the interaction of amines with chromium(III) porphyrins revealed a novel pathway to the formation of chromium(IV) oxido porphyrins. This has been used for electrochemical epoxidation reactions with dioxygen as the formal terminal oxidant.rn

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The Lasail mining area (Sultanate of Oman) was contaminated by acid mine drainage during the exploitation and processing of local and imported copper ore and the subsequent deposition of sulphide-bearing waste material into an unsealed tailings dump. In this arid environment, the use of seawater in the initial stages of ore processing caused saline contamination of the fresh groundwater downstream of the tailings dump. After detection of the contamination in the 1980s, different source-controlled remediation activities were conducted including a seepage water collection system and, in 2005, surface sealing of the tailings dump using an HDPE-liner to prevent further infiltration of meteoric water. We have been assessing the benefits of the remediation actions undertaken so far. We present chemical and isotopic (δ18O, δ 2H, 3H) groundwater data from a long-term survey (8–16 years) of the Wadi Suq aquifer along a 28 km profile from the tailings dump to the Gulf of Oman. Over this period, most metal concentrations in the Wadi Suq groundwater decreased below detection limits. In addition, in the first boreholes downstream of the tailings pond, the salinity contamination has decreased by 30 % since 2005. This decrease appears to be related to the surface coverage of the tailings pond, which reduces flushing of the tailings by the sporadic, but commonly heavy, precipitation events. Despite generally low metal concentrations and the decreased salinity, groundwater quality still does not meet the WHO drinking water guidelines in more than 90 % of the Wadi Suq aquifer area. The observations show that under arid conditions, use of seawater for ore processing or any other industrial activity has the potential to contaminate aquifers for decades.

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NORM (Naturally Occurring Radioactive Material) Waste Policies for the nation's oil and gas producing states have been in existence since the 1980's, when Louisiana was the first state to develop a NORM regulatory program in 1989. Since that time, expectations for NORM Waste Policies have evolved, as Health, Safety, Environment, and Social responsibility (HSE & SR) grows increasingly important to the public. Therefore, the oil and gas industry's safety and environmental performance record will face challenges in the future, about its best practices for managing the co-production of NORM wastes. ^ Within the United States, NORM is not federally regulated. The U.S. EPA claims it regulates NORM under CERCLA (superfund) and the Clean Water Act. Though, there are no universally applicable regulations for radium-based NORM waste. Therefore, individual states have taken responsibility for developing NORM regulatory programs, because of the potential radiological risk it can pose to man (bone and lung cancer) and his environment. This has led to inconsistencies in NORM Waste Policies as well as a NORM management gap in both state and federal regulatory structures. ^ Fourteen different NORM regulations and guidelines were compared between Louisiana and Texas, the nation's top two petroleum producing states. Louisiana is the country's top crude oil producer when production from its Federal offshore waters are included, and fourth in crude oil production, behind Texas, Alaska, and California when Federal offshore areas are excluded. Louisiana produces more petroleum products than any state but Texas. For these reasons, a comparative analysis between Louisiana and Texas was undertaken to identify differences in their NORM regulations and guidelines for managing, handling and disposing NORM wastes. Moreover, this analysis was undertaken because Texas is the most explored and drilled worldwide and yet appears to lag behind its neighboring state in terms of its NORM Waste Policy and developing an industry standard for handling, managing and disposing NORM. As a result of this analysis, fourteen recommendations were identified.^

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Questions relating to the transport of radioactive materials are very much an issue of current interest due to the increasing mobility of the materials involved in the nuclear fuel cycle, commitment to the environment, the safety and protection of persons and the corresponding regulatory legal framework. The radiological impact associated with this type of transport was assessed by means of a new data-processing tool that may be of use and serve as complementary documentation to that included in transport regulations. Thus, by determining the level of radiation at a distance of one metre from the transport vehicle and by selecting a route, the associated impacts will be obtained, such as the affected populations, the dose received by the most highly exposed individual, the overall radiological impact, the doses received by the population along the route and the possible detriment to their health. The most important conclusion is that the emissions of ionising radiation from the transport of radioactive material by road in Spain are not significant as regards the generation of adverse effects on human health, and that their radiological impact may be considered negligible.

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The focus of this research programme is to develop a single phase ceramic wasteform for waste PuO2 that is unsuitable for fuel manufacture. A suite of synthetic mineral systems have been considered including titanate, zirconate, phosphate and silicate based matrices. Although a wealth of information on plutonium disposition in some of the systems exists in the literature, the data is not always directly comparable which hinders comparison between different ceramic hosts. The crux of this research has been to compile a database of information on the proposed hosts to allow impartial comparison of the relative merits of each system. © 2009 Materials Research Society.