Remoção de metais pesados em efluentes sintéticos utilizando vermiculita como adsorvente

Heavy metals are used in many industrial processestheirs discard can harm fel effects to the environment, becoming a serious problem. Many methods used for wastewater treatment have been reported in the literature, but many of them have high cost and low efficiency. The adsorption process has been used as effective for the metal remoal ions. This paper presents studies to evaluate the adsorption capacity of vermiculite as adsorbent for the heavy metals removal in a synthetic solution. The mineral vermiculite was characterized by differents techniques: specific surface area analysis by BET method, X-ray diffraction, raiosX fluorescence, spectroscopy in the infraredd region of, laser particle size analysis and specific gravity. The physical characteristics of the material presented was appropriate for the study of adsorption. The adsorption experiments weredriveal finite bath metod in synthetic solutions of copper, nickel, cadmium, lead and zinc. The results showed that the vermiculite has a high potential for adsorption, removing about 100% of ions and with removal capacity values about 85 ppm of metal in solution, 8.09 mg / g for cadmium, 8.39 mg/g for copper, 8.40 mg/g for lead, 8.26 mg/g for zinc and 8.38 mg/g of nickel. The experimental data fit in the Langmuir and Freundlich models. The kinetic datas showed a good correlation with the pseudo-second order model. It was conducteas a competition study among the metals using vermiculiti a adsorbent. Results showed that the presence of various metals in solution does not influence their removal at low concentrations, removing approximat wasely 100 % of all metals present in solutions

Aplicação de tecnologias eletroquímicas (oxidação via radicais hidroxila, oxidação mediada via cloro ativo e eletrocoagulação) para o tratamento de efluentes reais ou sintéticos

In this work the degradation of real and synthetic wastewater was studied using electrochemical processes such as oxidation via hydroxyl radicals, mediated oxidation via active chlorine and electrocoagulation. The real effluent used was collected in the decanter tank of the Federal University of Rio Grande do Norte (ETE-UFRN) of Effluent Treatment Plant and the other a textile effluent dye Ácido Blue 113 (AB 113) was synthesized in the laboratory. In the electrochemical process, the effects of anode material, current density, the presence and concentration of chloride as well as the active chlorine species on site generated were evaluated. Electrodes of different compositions, Ti/Pt, Ti/Ru0,3Ti0,7O2, BDD, Pb/PbO2 and Ti/TiO2-nanotubes/PbO2 were used as anodes. These electrodes were subjected to electroanalytical analysis with the goal of checking how happen the anodic and cathodic processes across the concentrations of NaCl and supporting electrolyte used. The potential of oxygen evolution reaction were also checked. The effect of active chlorine species formed under the process efficiency was evaluated by removing the organic matter in the effluent-ETE UFRN. The wastewater treatment ETE-UFRN using Ti/Pt, DDB and Ti/Ru0,3Ti0,7O2 electrodes was evaluated, obtaining good performances. The electrochemical degradation of effluent-UFRN was able to promote the reduction of the concentration of TOC and COD in all tested anodes. However, Ti/Ru0,3Ti0,7O2 showed a considerable degradation due to active chlorine species generated on site. The results obtained from the electrochemical process in the presence of chloride were more satisfactory than those obtained in the absence. The addition of 0.021 M NaCl resulted in a faster removal of organic matter. Secondly, was prepared and characterized the electrode Ti/TiO2-nanotubes/PbO2 according to what the literature reports, however their preparation was to disk (10 cm diameter) with surface area and higher than that described by the same authors, aiming at application to textile effluent AB 113 dye. SEM images were taken to observe the growth of TiO2 nanotubes and confirm the electrodeposition of PbO2. Atomic Force Microscope was also used to confirm the formation of these nanotubes. Furthermore, was tested and found a high electrochemical stability of the electrode Ti/TiO2-nanotubes/PbO2 for applications such as long-term indicating a good electrocatalytic material. The electrochemical oxidation of AB 113 using Ti/Pt, Pb/PbO2 and Ti/TiO2-nanotubes/PbO2 and Al/Al (electrocoagulation) was also studied. However, the best color removal and COD decay were obtained when Ti/TiO2-nanotubes/PbO2 was used as the anode, removing up to 98% of color and 92,5% of COD decay. Analysis of GC/MS were performed in order to identify possible intermediates formed in the degradation of AB 113.

Remoção de metais pesados em efluentes sintéticos utilizando vermiculita como adsorvente

Heavy metals are used in many industrial processestheirs discard can harm fel effects to the environment, becoming a serious problem. Many methods used for wastewater treatment have been reported in the literature, but many of them have high cost and low efficiency. The adsorption process has been used as effective for the metal remoal ions. This paper presents studies to evaluate the adsorption capacity of vermiculite as adsorbent for the heavy metals removal in a synthetic solution. The mineral vermiculite was characterized by differents techniques: specific surface area analysis by BET method, X-ray diffraction, raiosX fluorescence, spectroscopy in the infraredd region of, laser particle size analysis and specific gravity. The physical characteristics of the material presented was appropriate for the study of adsorption. The adsorption experiments weredriveal finite bath metod in synthetic solutions of copper, nickel, cadmium, lead and zinc. The results showed that the vermiculite has a high potential for adsorption, removing about 100% of ions and with removal capacity values about 85 ppm of metal in solution, 8.09 mg / g for cadmium, 8.39 mg/g for copper, 8.40 mg/g for lead, 8.26 mg/g for zinc and 8.38 mg/g of nickel. The experimental data fit in the Langmuir and Freundlich models. The kinetic datas showed a good correlation with the pseudo-second order model. It was conducteas a competition study among the metals using vermiculiti a adsorbent. Results showed that the presence of various metals in solution does not influence their removal at low concentrations, removing approximat wasely 100 % of all metals present in solutions

Identificando práticas musicais e processos de aprendizagem musical no contexto urbano de Montes Claros-MG

MENDES,Jean Joubert Freitas; BRITO,Leila de Jesus Ferreira de;CARMO, Raiana Alves Maciel Leal do. Identificando práticas musicais e processos de aprendizagem musical no contexto urbano de Montes Claros-MG. In: ENCONTRO DA ASSOCIAÇAO NACIONAL DE PESQUISA E POS-GRADUAÇAO EM MUSICA (ANPPOM), 17.,2007, Sao Paulo. Anais... Sao Paulo: ANPPOM, 2007.

Coevolução e as práticas isomórficas de gestão: um estudo sobre os processos de mudanças institucionais no Instituto Federal de Educação, Ciência e Tecnologia do RN

The Federal Institution for Education, Science and Technology, in its historical path, has been living different changes. The transformations occurred along the way have been determined by coercive forces from the institutional environment, which has became more and more broad and complex throughout the time, obtaining diverse characteristics and new elements such as non institutional factors1 which started to contribute with the other changes. In this context, this work aims to study the isomorphic practices of the managers in the institutional changes process of the IFRN in 1998 and 2008, as of a theoretical coevolutionary perspective (CHILD; RODRIGUES; LEWIN; CARROL; VOLBERDA, 2003). This theory brings a new point of view for the organization analysis to the organizational studies, since it offers a non deterministic and non linear lection of the evolution process, which means, a coevolution. Thus, the organizations and their institutional and non institutional environment auto evolve, auto organize and auto reproduce. Therefore, the institutional and non institutional factors of the macro environment keep a continuous interdependence relationship with the organizations. For the means of this study, it is important to understand that is impossible to comprehend the object, the isomorphic practices, without considering that the previous institutional changes and its evolutions, its continuations and discontinuations, important in the coevolution process. As such, to call upon the institutional historical track is a fundamental aspect to materialize this study, for the recursive movement is indeed present in the coevolution. Another important point to make this research effective is that it is not possible to abdicate from the hologramatic view2 of this study, which considers the object, the isomorphic practices, part of the whole and this whole is also in the parts, therefore it is impossible to comprehend the object of study outside the context where it belongs. With this, as of the objective previously proposed, it is necessary to describe the characteristics of coevolution of the institutional changes related in 1998 and 2008; analyze the dynamic of the isomorphic mechanisms in its respective institutional change process; and describe the lessons learned which the isomorphic practices left to the IFRN, regarding its benefits and difficulties. All these transformations happened through coercive forces3 of the institutional environment. As of the Nineties, these forces became stronger, the environment became broader and more complex, with the emergency of new environmental factors. This study proposed to study the managing process and its practices, related to the micro environment, although it is required to articulate these actions, the demands and requirements from the macro environment. To make this research effective, semi structured interviews have been conducted with the managers who participated in both institutional change processes. In the results analysis, it has been possible to verify the particularity of each change, the one from 1998 with a strong normative action of the managers against coercive forces from the government for the search of recognition and the institutional legitimation and the one in 2008, which has been characterized by the normative action by managers in agreement with the coercive forces from the government, in favor of the government policy for the technological professional education. However, the results analysis it is possible to notice the evidence of a belonging feeling from the interviewed managers

Mudança dos processos de negócios e adequação da TI nas empresas em decorrência da implantação do sistema público de escrituração digital SPED: um estudo de casos múltiplos

Companies have always been organized by processes, often imperceptible to its employees. With the advancement of technology, organizational processes currently run an organization through computers, and thus generate immediate information that is available to each sector. With the objective of seeking business information in real time, the government created the SPED - Public System of Digital, which involves three subsystems, which are the Electronic Invoice, Digital Accounting Bookkeeping and Digital Tax Bookkeeping. This system is revolutionizing the business structures when gathering, in an innovative way, all information and interlinked business processes. For the implementation of SPED, a revision in the organizational processes is required, since the information is generated and is sent online to the government, without mistakes. Thus the study aimed to analyze the change brought about by the implementation of the Public System of Digital SPED in the main business processes. In order to do so, we have performed a multiple case study involving three companies in the state of Para, two operate in wholesale and one explores agribusiness. The Data collection was performed by accounting professionals, IT and managers. According to the results obtained, it was found that in two companies, the IT infrastructure was capable of deploying the new system without major problems, while one company had more difficulties to cope with the new system. However, all companies had to examine its processes to make the customizations needed to fit. It was also observed that there is no IT Governance in two companies. Therefore, we recommend the use of an appropriate model, not only for the implementation of SPED, but as a way to manage and extract better results from investment in information technology

A forma do privilégio: renda, acessibilidade e densidade em Natal-RN

The aim of this work is to understand the morphological expression of ground occupation by the higher income population, by focusing on population distribution in accordance with income layers and demographical density, as well as topological accessibility (HILLIER and HANSON, 1984) resulting from the urban grid structure. It endeavors to identify a functional organizing principle regarding the intra-urban space of Natal capital city of the state of Rio Grande do Norte, the research focus. In order to achieve this, census data as well as syntactic data were utilized for mapping and spatial analysis of income patterns, topological accessibility and demographical density using Geographical Information System GIS. The organizing principle was named as the Form of Privilege, a pattern that concentrates or tends to concentrate wealth, topological accessibility and low demographical density. Attempting to assess its extent, beyond Natal, this principle was applied to other Brazilian northeastern capitals such as: Fortaleza, CE; Teresina, PI; Aracaju, SE; Recife, PE; and João Pessoa, PB. Findings point out that although the urban structures of these cities are not immune to the Form of Privilege, Natal is emblematic of this phenomenon, a fact that demonstrates the perverse character of its spatial process, which historically creates privileged areas within the city, by means of the appropriation of accessibility as well as of the many urban benesses that are related to it by higher income groups at the expense of the major part of the population, which though being the people mostly in need of the benefits originating from the urban form are excluded from them

Configurando a cidade contemporânea em Natal : os processos espaciais em Ponta Negra

This dissertation is about the spatial configuration in Natal and processes in the Ponta Negra neighborhood today. Ponta Negra has undergone a number of critical social and spatial changes due to tourism development after the 1990s. It is of special interest to consider the intensification of real estate investment after 2000, when the new airport terminal, located in the neighboring municipality of Parnamirim, was in use. Ponta Negra is the place where most tourists go to, so attracting considerable public investments. New agents of transformation have produced change in the neighborhood as well. The present study aims at analysing the spatial processes in this part of the city. Here, the spatial configuration that resulted from extended real estate investments, both public and private, in recent years, is analysed in detail. The study identifies the multually differentiated, however internally homogenous areas. The concepts of production of space, contemporanean urban development and spatial dynamics are discussed. The research is based on document analysis and field work. Results were plotted to maps and tables. A detailed analysis of the spatial processes in the Ponta Negra neighborhood is undertaken as a conclusion, considering the contemporanean global scenario

Interesses da habitação social : políticas e processos no Rio Grande do Norte

En 2003, le gouvernement brésilien (gestion Lula) a initié une nouvelle phase dans son histoire de l habitation, en intensifiant les constructions de logements sociaux au Brésil. Un tel accroissement a eut des répercussions tant en ville comme à la campagne, et fût marqué dans le Rio Grande do Norte, par la production a grande échelle d ensembles d habitations, dans les programmes de Gouvernement. Afin de viabiliser ces transformations, des instruments politiques, financiers et de gestion ont étés articulés conjointement, utilisant la répétition d une typologie d édification, comme modèle, accompagnée de la reproduction d une morphologie dans les constructions de logements sociaux. Afin de comprendre ce processus nous introduisons une recherche urbanistique et socio-économique du problème du logement social au Brésil, en cherchant à mettre en relation les aspects techniques avec les questions historique, professionnelles et culturelles, éléments complémentaires. Notre analyse cherche a identifier comment les politiques de gestion et financement officielles (administrées dans sa grande majorité par la Caisse Économique Fédérale -CEF-), influencent le processus de conception de projets, en provoquant les répétitions de type/morphologiques, déjà citées. Basée sur l observation directe au cour de deux expériences différenciées pour du logement social en milieu rural, au Rio Grande do Norte, nous montrerons aussi certaines limitations et possibilités des acteurs sociaux, face aux agents et politiques officielles pour le logement social au Brésil, proposant des solutions alternatives standardisées qui caractérisent le résultat des projets financées et gérés par la CEF. Nos principales références théoriques et méthodologiques sont Nabil Bonduki (1998), David Harvey (2009,1982), Henry Lefèbvre (1970), Ermínia Maricato (2010, 2009, 2000, 1987) et Raquel Rolnik (2010, 2009, 2008, 1997)

O processo de urbanização de Mossorò: dos processos históricos à estrutura urbana atual

The general objective of this academic work is to analyze the relationship between the territorial division and the urban expansion process of Mossoró city, understood here as the production and occupation of space. The urban expansion in Mossoró, since its formation as settlement in 1772 until current days, identifies with the Brazilian urbanization process whose growth is determined by the capitalist development. Thus, the expansion was determined by several economical specializations imposed by the territorial division of work which occurs at an interregional level, and, sometimes at an international level. Then, each specialization determined a moment of the urban expansion of the city, as follows: a) The cattle farmer specialization, between 1772 and 1857, when the urban expansion was shy, is summarized to a commercial square that received goods from Aracati aiming to cover a wide rural area; b) The commercial emporium specialization, between 1857 and 1930, when the urban expansion took an important impulse with the concentration of public and private capitals; c) The salt industry and the agricultural-industrial exporter specialization inside a state of development policy, between 1930 and 1970, when the urban expansion, joined to the settlement of the working class in the urban soil, developed along an important axis -the railway; d) The render of services specialization inside a state of intervention policy, between 1970 and 1990, when the urban expansion was characterized by the accelerated growth rhythm, by the reuse of some spaces, and by space segregation of demanding people; e) The render of services policy inside a neoliberal state policy, since 1990 until current days, when the urban expansion reduced its rhythm abruptly, when only small alterations occurred in the existing spaces. It focused on social policies and on several slums eradication programs. Finally, the territorial structure is deeply articulated with others, no territorial, but economical, social and political, which happens at a national, regional and local rate. Only within a historical and conceptual panorama, it was possible to explain the urban expansion in Mossoró from its formation in 1772 until current days. Therefore, this work is a several discipline analysis of the urbanization process existing in Mossoró

Reconfiguração dinâmica de estratégias distribuídas em dispositivos foundation fieldbus para a otimização de processos na indústria do petróleo

The petrochemical industry has as objective obtain, from crude oil, some products with a higher commercial value and a bigger industrial utility for energy purposes. These industrial processes are complex, commonly operating with large production volume and in restricted operation conditions. The operation control in optimized and stable conditions is important to keep obtained products quality and the industrial plant safety. Currently, industrial network has been attained evidence when there is a need to make the process control in a distributed way. The Foundation Fieldbus protocol for industrial network, for its interoperability feature and its user interface organized in simple configuration blocks, has great notoriety among industrial automation network group. This present work puts together some benefits brought by industrial network technology to petrochemical industrial processes inherent complexity. For this, a dynamic reconfiguration system for intelligent strategies (artificial neural networks, for example) based on the protocol user application layer is proposed which might allow different applications use in a particular process, without operators intervention and with necessary guarantees for the proper plant functioning

Estimação e compensação de não linearidades inerentes aos atuadores dos processos industriais

The oscillations presents in control loops can cause damages in petrochemical industry. Canceling, or even preventing such oscillations, would save up to large amount of dollars. Studies have identified that one of the causes of these oscillations are the nonlinearities present on industrial process actuators. This study has the objective to develop a methodology for removal of the harmful effects of nonlinearities. Will be proposed an parameter estimation method to Hammerstein model, whose nonlinearity is represented by dead-zone or backlash. The estimated parameters will be used to construct inverse models of compensation. A simulated level system was used as a test platform. The valve that controls inflow has a nonlinearity. Results and describing function analysis show an improvement on system response

Controle preditivo neural aplicado à processos petroquímicos

A pesquisa tem como objetivo desenvolver uma estrutura de controle preditivo neural, com o intuito de controlar um processo de pH, caracterizado por ser um sistema SISO (Single Input - Single Output). O controle de pH é um processo de grande importância na indústria petroquímica, onde se deseja manter constante o nível de acidez de um produto ou neutralizar o afluente de uma planta de tratamento de fluidos. O processo de controle de pH exige robustez do sistema de controle, pois este processo pode ter ganho estático e dinâmica nãolineares. O controlador preditivo neural envolve duas outras teorias para o seu desenvolvimento, a primeira referente ao controle preditivo e a outra a redes neurais artificiais (RNA s). Este controlador pode ser dividido em dois blocos, um responsável pela identificação e outro pelo o cálculo do sinal de controle. Para realizar a identificação neural é utilizada uma RNA com arquitetura feedforward multicamadas com aprendizagem baseada na metodologia da Propagação Retroativa do Erro (Error Back Propagation). A partir de dados de entrada e saída da planta é iniciado o treinamento offline da rede. Dessa forma, os pesos sinápticos são ajustados e a rede está apta para representar o sistema com a máxima precisão possível. O modelo neural gerado é usado para predizer as saídas futuras do sistema, com isso o otimizador calcula uma série de ações de controle, através da minimização de uma função objetivo quadrática, fazendo com que a saída do processo siga um sinal de referência desejado. Foram desenvolvidos dois aplicativos, ambos na plataforma Builder C++, o primeiro realiza a identificação, via redes neurais e o segundo é responsável pelo controle do processo. As ferramentas aqui implementadas e aplicadas são genéricas, ambas permitem a aplicação da estrutura de controle a qualquer novo processo

Atenuação de ruídos coerentes utilizando decomposição em modos empíricos

The seismic processing technique has the main objective to provide adequate picture of geological structures from subsurface of sedimentary basins. Among the key steps of this process is the enhancement of seismic reflections by filtering unwanted signals, called seismic noise, the improvement of signals of interest and the application of imaging procedures. The seismic noise may appear random or coherent. This dissertation will present a technique to attenuate coherent noise, such as ground roll and multiple reflections, based on Empirical Mode Decomposition method. This method will be applied to decompose the seismic trace into Intrinsic Mode Functions. These functions have the properties of being symmetric, with local mean equals zero and the same number of zero-crossing and extremes. The developed technique was tested on synthetic and real data, and the results were considered encouraging

Contribuição ao desenvolvimento de ontologias para processos petroquímicos : estudo de caso em uma planta DEA

In the last decades, the oil, gas and petrochemical industries have registered a series of huge accidents. Influenced by this context, companies have felt the necessity of engaging themselves in processes to protect the external environment, which can be understood as an ecological concern. In the particular case of the nuclear industry, sustainable education and training, which depend too much on the quality and applicability of the knowledge base, have been considered key points on the safely application of this energy source. As a consequence, this research was motivated by the use of the ontology concept as a tool to improve the knowledge management in a refinery, through the representation of a fuel gas sweetening plant, mixing many pieces of information associated with its normal operation mode. In terms of methodology, this research can be classified as an applied and descriptive research, where many pieces of information were analysed, classified and interpreted to create the ontology of a real plant. The DEA plant modeling was performed according to its process flow diagram, piping and instrumentation diagrams, descriptive documents of its normal operation mode, and the list of all the alarms associated to the instruments, which were complemented by a non-structured interview with a specialist in that plant operation. The ontology was verified by comparing its descriptive diagrams with the original plant documents and discussing with other members of the researchers group. All the concepts applied in this research can be expanded to represent other plants in the same refinery or even in other kind of industry. An ontology can be considered a knowledge base that, because of its formal representation nature, can be applied as one of the elements to develop tools to navigate through the plant, simulate its behavior, diagnose faults, among other possibilities