76 resultados para Problemas ambientais urbanos


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In Brazil many types of bioproducts and agroindustrial waste are generated currently, such as cacashew apple bagasse and coconut husk, for example. The final disposal of these wastes causes serious environmental issues. In this sense, waste lignocellulosic content, as the shell of the coconut is a renewable and abundant raw material in which its use has an increased interest mainly for the 2nd generation ethanol production. The hydrolysis of cellulose to reducing sugars such as glucose and xylose is catalysed by a group of enzymes called cellulases. However, the main bottleneck in the enzymatic hydrolysis of cellulose is the significant deactivation of the enzyme that shows irreversible adsorption mechanism leading to reduction of the cellulose adsorption onto cellulose. Studies have shown that the use of surfactants can modify the surface property of the cellulose therefore minimizing the irreversible binding. The main objective of the present study was to evaluate the influence of chemical and biological surfactants during the hydrolysis of coconut husk which was subjected to two pre-treatment in order to improve the accessibility of the enzymes to the cellulose, removing this way, part of the lignin and hemicellulose present in the structure of the material. The pre-treatments applied to coconut bagasse were: Acid/Alkaline using 0.6M H2SO4 followed by 1M NaOH, and the one with Alkaline Hydrogen Peroxide at a concentration of 7.35% (v/v) and pH 11.5. Both the material no treatment and pretreated were characterized using analysis of diffraction X-ray (XRD), Scanning Electron Microscopy (SEM) and methods established by NREL. The influence of both surfactants, chemical and biological, was used at concentrations below the critical micelle concentration (CMC), and the concentrations equal to the CMC. The application of pre-treatment with coconut residue was efficient for the conversion to glucose, as well as for the production of total reducing sugars, it was possible to observe that the pretreatment fragmented the structure as well as disordered the fibers. Regarding XRD analysis, a significant increase in crystallinity index was observed for pretreated bagasse acid/alkali (51.1%) compared to the no treatment (31.7%), while that for that treated with PHA, the crystallinity index was slightly lower, around 29%. In terms of total reducing sugars it was not possible to observe a significant difference between the hydrolysis carried out without the use of surfactant compared to the addition of Triton and rhamnolipid. However, by observing the conversions achieved during the hydrolysis, it was noted that the best conversion was using the rhamnolipíd for the husk pretreated with acid/alkali, reaching a value of 33%, whereas using Triton the higher conversion was 23.8%. The coconut husk is a residue which can present a high potential to the 2nd generation ethanol production, being the rhamonolipid a very efficient biosurfactant for use as an adjuvant in the enzymatic process in order to act on the material structure reducing its recalcitrance and therefore improving the conditions of access for enzymes to the substrate increasing thus the conversion of cellulose to glucose.

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In Brazil many types of bioproducts and agroindustrial waste are generated currently, such as cacashew apple bagasse and coconut husk, for example. The final disposal of these wastes causes serious environmental issues. In this sense, waste lignocellulosic content, as the shell of the coconut is a renewable and abundant raw material in which its use has an increased interest mainly for the 2nd generation ethanol production. The hydrolysis of cellulose to reducing sugars such as glucose and xylose is catalysed by a group of enzymes called cellulases. However, the main bottleneck in the enzymatic hydrolysis of cellulose is the significant deactivation of the enzyme that shows irreversible adsorption mechanism leading to reduction of the cellulose adsorption onto cellulose. Studies have shown that the use of surfactants can modify the surface property of the cellulose therefore minimizing the irreversible binding. The main objective of the present study was to evaluate the influence of chemical and biological surfactants during the hydrolysis of coconut husk which was subjected to two pre-treatment in order to improve the accessibility of the enzymes to the cellulose, removing this way, part of the lignin and hemicellulose present in the structure of the material. The pre-treatments applied to coconut bagasse were: Acid/Alkaline using 0.6M H2SO4 followed by 1M NaOH, and the one with Alkaline Hydrogen Peroxide at a concentration of 7.35% (v/v) and pH 11.5. Both the material no treatment and pretreated were characterized using analysis of diffraction X-ray (XRD), Scanning Electron Microscopy (SEM) and methods established by NREL. The influence of both surfactants, chemical and biological, was used at concentrations below the critical micelle concentration (CMC), and the concentrations equal to the CMC. The application of pre-treatment with coconut residue was efficient for the conversion to glucose, as well as for the production of total reducing sugars, it was possible to observe that the pretreatment fragmented the structure as well as disordered the fibers. Regarding XRD analysis, a significant increase in crystallinity index was observed for pretreated bagasse acid/alkali (51.1%) compared to the no treatment (31.7%), while that for that treated with PHA, the crystallinity index was slightly lower, around 29%. In terms of total reducing sugars it was not possible to observe a significant difference between the hydrolysis carried out without the use of surfactant compared to the addition of Triton and rhamnolipid. However, by observing the conversions achieved during the hydrolysis, it was noted that the best conversion was using the rhamnolipíd for the husk pretreated with acid/alkali, reaching a value of 33%, whereas using Triton the higher conversion was 23.8%. The coconut husk is a residue which can present a high potential to the 2nd generation ethanol production, being the rhamonolipid a very efficient biosurfactant for use as an adjuvant in the enzymatic process in order to act on the material structure reducing its recalcitrance and therefore improving the conditions of access for enzymes to the substrate increasing thus the conversion of cellulose to glucose.

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O artigo apresenta os principais elementos que compõem a questão ambiental na sociedade global, através de sua relação entre economia, meio ambiente e política internacional. A primeira parte expõe o debate ambiental no contexto internacional, enfocando-o a partir dos anos 1960, período em que os problemas ambientais surgem com mais intensidade e com eles os protestos sociais nos países centrais. Os encontros sobre política ambiental internacional foram realizados com mais frequência nos anos setenta como a conferência internacional sobre meio ambiente, a primeira chancelada pela ONU em Estocolmo, 1972. Nas décadas de 1970/1980 as autoridades governamentais reconheceram a urgência na resolução da crise ambiental e passaram a traçar estratégias para a mitigação e contenção da crise. A década de 1990 é marcada pela Conferência Rio 1992, que lançou o desenvolvimento sustentável, o qual recomenda que as gerações presentes devem se reproduzir sem comprometer a capacidade de reprodução das gerações futuras. Os encaminhamentos da terceira conferência internacional sobre meio ambiente (Johanesburgo, 2002) condicionaram a questão ambiental à necessidade da formulação de leis ambientais por parte dos Estados Nacionais e instrumentos económicos de gestão ambiental. Na Rio + 20, o tema central foi a economia verde, que surge como alternativa ao desenvolvimento sustentável e se relaciona a mitigação das mudanças climáticas, produção de baixo carbono, eficiência energética, energia renovável etc. O texto se encerra explanando sobre a questão ambiental internacional na sociedade global.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

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Universidade Federal do Rio Grande do Norte

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The growing world demand for energy supplied by fossil fuels, a major contributor to the emission of pollutants into the atmosphere and causing environmental problems, has been encouraging governments and international organizations to reflect and encourage the use of alternative renewable sources. Among these new possibilities deserves attention biodiesel, fuel cleaner and easy to reproduce. The study of new technologies involving that source is necessary. From this context, the paper aims at analyzing the thermal stability by thermogravimetric analysis, of the waste generated from atmospheric distillation of mixtures with ratios of 5, 10, 15 and 20% palm biodiesel in diesel with and without addition of BHT antioxidant. It was synthesized biodiesel through palm oil, via homogeneous catalysis in the presence of KOH, with and without the use of BHT and subsequently added to the diesel common indoor type (S1800) from a gas station BR. The diesel was already added with 5% biodiesel, and thus the proportions used for these blends were subtracted from the existing ratio in diesel fuel, resulting in the following proportions palm oil biodiesel: 0% (B5), 5% (B10), 10 % (B15) and 15% (B20). From atmospheric distillation analysis, performed in mixtures with and without BHT were collected residue generated by each sample and performed a thermal study from the thermogravimetric analysis at a heating rate of 10 °C.min-1, nitrogen atmosphere and heating to 600 ° C. According to the specifications of Resolution No. 7/2008 for biodiesel, it was found that the material was synthesized in accordance with the specifications. For mixtures, it was noted that the samples were in accordance with the ANP Resolution No. 42/2009. Given the TG / DTG curves of the samples of waste mixtures with and without BHT antioxidant was able to observe that they showed a single stage of thermal decomposition attributed to decomposition of heavy hydrocarbons and esters and other heavier constituents of the waste sample weighed. The thermal behavior of residues from atmospheric distillation of mixtures of diesel / biodiesel is very important to understand how this affects the proper functioning of the engine. A large amount of waste can generate a high content of particulate material, coke formation and carbonaceous deposits in engine valves, compromising their performance

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

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This research presents a study investigating the correlation between the environmental-physycal charcateristics of cities and the formation of its micro-climates. The study was conducted in the central area of Fortaleza characterized as a stable and consolidated area, where the city originated and currently faces serious problems in its urban dynamics. The points of measurements were determined by the elaboration and analysis of topography maps, height of buildings, land use, type of surface coating and vegetation, following the methodology of Katzschner (1997). A zoning map was then determined, according to common morphological characteristics of the 12 measurement points, which were based on a set of Romero s (2001) bioclimatic criteria. Air measurements, temperature, humidity, intensity and direction of winds were made in transect form in two different circuits in the study area, with six points of data collection in each area, in three different times: 6:00 am, 1:00pm and 7:00pm, during two periods of the year: August 2008 and March 2009. The results verified the influence of different environmental-physical types in the behavior of the climatic variables that were collected. A verticalização tão condenada em algumas situações se bem equilibrada e controlada pode reduzir as temperaturas do ar através do sombreamento dos espaços urbanos e possibilidade de maior permeabilidade a ventilação natural. The highest average air temperature and lower humidity were recorded at the point I at all times. This situation may have been in result of the high density, poor vegetation and extended paving of the ground. According to the results, it s clear the positive influence vegetation has on easing air temperature. Another indicator observed that areas with a greater variation in building heights tend to present decreased average air temperature. High rise structure, planned in accordance to urban air quality parameters, can reduce air temperatures by the shading of urban spaces and the possibility of greater penetration of natural ventilation

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The growing accumulation of people in urban centers caused chronic problems of the cities to begin to take an increasingly unsustainable. Primarily related to lack of infrastructure coupled with sanitation and lack of investment in critical sectors such as health, education, housing and transportation, these problems start to deteriorate markedly the quality of life of city dwellers and put into test management policies of the spaces urbanized. To reverse this situation, shows is essential to the use of tools (highlighting this harvest rates and environmental indicators) that help in assessing the current conditions and may assist in predicting future scenarios. From the information listed above, now put the research seeks to present an index called ISBA Environmental (Sanitation Index) which looks at the four urban systems (water, sewer, solid waste and urban drainage) from the viewpoint of application in a geographical cutout specific - in this case the Drainage Basin XII, defined by the Plan of Urban Drainage Stormwater in the city of Natal, capital of Rio Grande do Norte. This index, together with analysis of other factors sought to trace the current conditions of the basin and thus, assist in proposing the best solutions. For the preparation of the index was applied a questionnaire with a sample of 384 (three hundred eighty-four) households that aimed to study two variables: access to services and satisfaction of the population in relation to these. The ISBA has shown that the system is the most deficient collection and disposal of effluents (ICE = 47.66%), followed by the drainage of rainwater (IDAP = 54.17%), water supply (AAI = 61, 36) and solid waste collection (IRS = 78.28). With the ISBA was possible to verify that the qualitative data shows whose subjectivity is evident (as is the case of user satisfaction) can be of great importance when an assessment, since we obtained the correlation coefficient between the variables "Access" and " Satisfaction "equal to 0.8234, showing a strong correlation between the existence / quality of service offered and the impressions of the population that receives them

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Nowadays, the urban chaos brings some problems to the citizens such as mental fatigue, irritability and lack of attention, emphasizing the need for open urban spaces, capable to contribute to the restoration of physical and mental balance of people. By the variety of alternative uses available, many of them related to the stimulus of entertainment activities, the squares have been identified as restorative environments, especially by its potential as a place of leisure. In this context, the objective of this dissertation is to understand the use of the square as leisure environment, by a square in Natal RN, establishing the relationship between environmental and behavioral characteristics. More specifically, I attempt to identify the major activities that happen there, the people that develop them and the spatial and temporal configurations of this occupation. Among the 290 squares available in the city, the Kalina Maia Square was selected, which is located in the district of Lagoa Nova. The case study chosen was based on criteria relating to scale, shape, location on the urban environment, variability of uses and conservation status. In the study were used behavioral mapping place-centered and people-centered, behavior trace analysis and 14 interviews. The results show that the square is used by people from different ages and social classes, subdivided into groups with specific days and times. These users are usually engaged in activities related to various types of leisure, with sports predominance. The relationship between spatial configuration and behavior shows that there is a sectorization of uses, being possible to identify the environmental characteristics that most favor observed activities, especially in relation to shading and presence of furniture and equipment. Moreover, throughout the day it appears that the affordances inherent to the various fixed objects on the square are decoded differently by various categories of users, by giving them insights that help the development of leisure activities that characterize each group

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In urban, flooding and landslides are among the troubles that most bring human and material loss. Therefore, this study objected to perform an analysis on the risk perception on the population living in social environmental vulnerable places in order to understand what is the way this population realize the risks they are exposed to and what are the outbrave strategies the develop. The first analyzed area was Complexo Passo da Pátria for the flooding risk problematic and then the Cidade Nova neighborhood threatened by the dunes slides. The areas locate, respectively, in the West and East zones of Natal-RN. Using an interview screenplay adapted from risk perception researches from different brazilian cities, it was collected primarily data on the variables: perception, evaluation and choice, safety threshold, adjustment, decision and participation. Due to the studied areas characteristics the qualitative approach adjusted itself to the difficulties for accessing the areas. The studied places characterize for its insecure situation like selling/using drugs, robbery and murder among others. Due to this situation the interviewed individuals were the ones that could be found more accessibly and available in the moment and the interviews were made in the community leader presence of each area. Through the discourse of the respondents analysis it was able to conclude that the interviewed population is exposed to a high vulnerability grade and risks. However it was identified substantial differences between the perception and risks of Complexo Passo da Pátria and bairro Cidade Nova, because in the first area the intervied ones can recognize the high risk they are exposed to in a more emphatic way to the interviewed ones for the Cidade Nova neighborhood. Furthermore, there is a heavy dissatisfaction for the population of the two places about the city hall positions relating to the present problems in the studied areas. It was also identified the strategy development of acquaintanceship with the risk in the research places beyond a feeling of belonging and affection between the dwellers and the places, yet it was more evident for Complexo Passo da Pátria. Though this analysis it was possible to understand and perceptions and the behavior of the individuals or social groups facing the risks as acceptance and rejection of determined risks beyond adaptation measures of living together with the persistence presence of risks. Therefore, qualitative nature researches emphasizing the perception approach are in the fundamental importance in the studies about risks making it possible to offer aids to the urban planning and management in the implement of effective preventive measures and compatible with the population aims

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rates in the Brazilian cities, which time there is an inexistent theoretical reflection about public policy statement adding the way of Urban Solid Waste (USW) and tailing integrated management plans in the majorly Brazilian cities. The unappropriated solid waste disposal and final pollution result in a strong socioenvironmental problems and material extravagancies that should be used to recycling and reusing waste material, besides bringing immense challenges for the thematic Strategy Urban and Environmental Management it considers the Sustainable City Model. Moreover, this labor projects a discussion about USW problematic through legally and environmentally point of view, including the public environmental policy and the social technologies as resolution tactics. At that time, it reports rights, scientific articles, documents and Environmental Law Doctrine on findings thematic studies, also the propose displays an interdisciplinary research methodology which combines bibliographic method - focusing theory aspects of the legally environmentally guiding principle, public policy and social technologies. Those are theorist features very important to create a Municipal Integrated Solid Waste Management Plan (PMGIRS) - modus operandi of the Federal Law n. 12.305/2010 (National Solid Waste Policy - PNRS). That policy is interesting to receive financial resources from federal government (Cities Ministry; idem, Federal Decree n. 7.404/2010 and Federal Law n. 10.257/2001) helping the preservation of the environment, regional development, generation of jobs and income (art. 6º), in addition broadening spreading’s private companies dedicated to waste management. Consequently, the PNRS contains a set of guidelines and general procedures; it should be an operation of this legal policy contextualized by Social Technologies theory (TS) into social issues, legal, economic and environmental aspects. Therefore, this research notes the possibility of public policy statement implementation over and done with the PNRS by the terms of development and sustainability in the urban space.

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This research presents a study investigating the correlation between the environmental-physycal charcateristics of cities and the formation of its micro-climates. The study was conducted in the central area of Fortaleza characterized as a stable and consolidated area, where the city originated and currently faces serious problems in its urban dynamics. The points of measurements were determined by the elaboration and analysis of topography maps, height of buildings, land use, type of surface coating and vegetation, following the methodology of Katzschner (1997). A zoning map was then determined, according to common morphological characteristics of the 12 measurement points, which were based on a set of Romero s (2001) bioclimatic criteria. Air measurements, temperature, humidity, intensity and direction of winds were made in transect form in two different circuits in the study area, with six points of data collection in each area, in three different times: 6:00 am, 1:00pm and 7:00pm, during two periods of the year: August 2008 and March 2009. The results verified the influence of different environmental-physical types in the behavior of the climatic variables that were collected. A verticalização tão condenada em algumas situações se bem equilibrada e controlada pode reduzir as temperaturas do ar através do sombreamento dos espaços urbanos e possibilidade de maior permeabilidade a ventilação natural. The highest average air temperature and lower humidity were recorded at the point I at all times. This situation may have been in result of the high density, poor vegetation and extended paving of the ground. According to the results, it s clear the positive influence vegetation has on easing air temperature. Another indicator observed that areas with a greater variation in building heights tend to present decreased average air temperature. High rise structure, planned in accordance to urban air quality parameters, can reduce air temperatures by the shading of urban spaces and the possibility of greater penetration of natural ventilation

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La présente étude a comme objectif comprendre la relation entre l implantation et le développement du Tourisme à Natal et les conflits urbains établits entre 2006 et 2010 et publiés par les médias imprimés, élaborant ses impacts dans le quotidien des résidents. Tandis qu une relecture partielle de la méthode régressive-progressive développée par le philosophe français Henri Lefebvre, cherche à recouper du présent, des contradictions qui promeuvent des réactions dans le quotidien de la ville; ainsi qu identifier des moments du passé qui puissent contribuer à sa compréhension. Aujourd hui, nous avons les médias, comme principale source pour observer la perception locale des problèmes causés par l espace conçu, à partir des actions de l État référentes à l activité. Par rapport au passé, ces situations sont recherchées dans des sources secondaires, mettant en évidence le dialogue avec le Relatório Conflitos Urbanos (Rapport Conflits Urbains) à Natal-1976-1986 (ANDRADE et al.,1986), qui présente les conflits existants à des moments qui ont précédé ou ont acompagné le début du développement de l activité au RN, spécialement à Natal. Alors que dans la contribution à la compréhension du rôle du Tourisme dans l apparition de conflits urbains de la ville sont aussi inclues nos coupures vécues, des actions de l État par rapport à la consolidation, ainsi comme pour les conflits qui se sont plus demarqués ou qui ont conduit à la réaction de la population de la ville pendant les périodes analysées. Au final, on cherche à démontrer les limites de la responsabilité de l activité touristique dans l urgence des principaux conflits urbains dans la ville. L analyse des données de la recherche, avec l identification des conflits urbains de Natal et sa relation avec le Tourisme; la présentation des conflits par rapport à la localisation, fréquence et son encadrement dans les catégories de l analyse adoptée; l identification des agents intéressés et la relation entre eux; ont amené à la confirmation de l hypothèse proposée. De cette façon, en prenant en compte les coupures temporelles et spatiales, la source de recherche et la méthodologie adoptées, nous arrivons à la conclusion que l activité touristique à Natal n est pas directement responsable de l apparition des conflits urbains de la ville

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The production of waste from urban and industrial activities is one of the factors of environmental contamination and has aroused attention of the scientific community, in the sense of its reuse. On the other hand, the city of Salvador/Ba, with approximately 262 channels, responsible for storm water runoff, produces every year, by the intervention of cleaning and clearing channels, a significant volume of sediments (dredged mud), and thus an appropriate methodology for their final destination. This study aims to assess the influence of incorporation of these tailings in arrays of clay for production of interlocked block ceramic, also known as ceramic paver. All the raw materials from the metropolitan region of Salvador (RMS) were characterized by x-ray fluorescence, x-ray diffraction, thermal analysis (TG and TDA), particle size analysis and dilatometry. With the use of statistical experimental planning technique, ternary diagram was defined in the study region and the analyzed formulations. The specimens were prepared with dimensions of 60x20x5mm³, by uniaxial pressing of 30 MPa and after sintering at temperatures of 900°, 1000º and 1100ºC the technological properties were evaluated: linear shrinkage, water absorption, apparent porosity, apparent specifies mass, flexural rupture and module. For the uniaxial compression strength used cylindrical probe body with Ø 50 mm. The standard mass (MP) was prepared with 90% by weight of clay and 10% by weight of Channel sediment (SCP), not being verified significant variations in the properties of the final product. With the incorporation of 10% by weight of manganese residue (PFM) and 10% by weight of the Ceramic waste (RCB) in the mass default, in addition to adjusting the plasticity due to less waste clay content, provided increased linear firing shrinkage, due the significant concentration of K2O, forming liquid phase at low temperature, contributing to decreased porosity and mechanical resistance, being 92,5 MPa maximum compressive strength verified. After extract test leachate and soluble, the piece containing 10% of the PFM, was classified as non-hazardous and inert material according to NBR10004/04 ABNT. The results showed the feasibility on using waste, SCP, RCB and PFM clay mass, at temperatures above 900ºC, paver ceramic production, according to the specifications of the technical standards, so that to exceed the 10% of the PFM, it becomes imperative to conduct studies of environmental impacts