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O tema água no ensino: a visão de pesquisadores e de professores de Química; The subject of water in education: the vision of researchers and chemistry teachers

Torralbo, Daniele
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 16/11/2009 PT
Relevância na Pesquisa
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O tema "água" tem sido considerado importante no ensino da química, pois permite ao professor problematizar situações importantes para que os alunos a interpretem, de maneira que os conceitos químicos possam auxiliar no entendimento de problemas, propiciando assim, a formação de um estudante responsável. A presente pesquisa buscou investigar como os professores de Química do Ensino Médio abordam esse tema em suas aulas, e conhecer as visões de especialistas sobre os conhecimentos relevantes que a sociedade, de maneira geral, deveria ter sobre a água, bem como o que deveria ser ensinado dessa temática na escola. Os dados foram coletados entre 6 pesquisadores em Química Ambiental QA, 6 em Química das águas QAG, 5 em Educação Ambiental EA e 8 em Ensino de Química EQ, e 10 professores de Química do Ensino Médio. Utilizou-se um questionário para os pesquisadores em QA, QAG e EA e outro para os EQ. Os professores foram entrevistados. A análise dos dados foi feita de acordo com os pressupostos teóricos e metodológicos da análise de conteúdo e foram construídas tramas de conhecimentos. As categorias elaboradas dizem respeito a três dimensões de análise: conhecimentos, atitudes e à abordagem do tema. Ainda procurou-se identificar com que visões sobre o ambiente a temática água deveria ser abordada. Para os pesquisadores em ensino de Química EQ...

A estrutura e organização da ciência química na visão de estudantes de graduação: uma aplicação da técnica de mapeamento conceitual; The structure and organization of Chemistry concerned by undergraduate students: an application of conceptual mapping

Oliveira, Iara Terra de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 05/05/2011 PT
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Este trabalho analisa algumas das atividades desenvolvidas no âmbito da disciplina Química Integrada III, oferecida no segundo semestre de 2008 a alunos que então cursavam o sexto semestre dos cursos do IQ-USP do período noturno. As atividades desenvolvidas na disciplina tiveram como finalidade promover a reflexão dos alunos a respeito de suas concepções sobre a natureza e a organização da Química como ciência, e da natureza das relações existentes entre os conceitos (conteúdos) aprendidos nas diferentes disciplinas do curso de graduação. Com o intuito de promover tal reflexão, a disciplina em questão utilizou como ferramenta a elaboração em grupos de dois mapas conceituais. O primeiro mapa conceitual tinha como objetivo que os alunos mostrassem explicitamente as principais relações existentes entre os conceitos estudados em seu curso. Já o segundo mapa conceitual tinha como objetivo representar a visão dos estudantes a respeito da organização estrutural da Química. A análise dos conceitos utilizados e da relação expressa entre os mesmos permitiu observar que as disciplinas do curso e as cinco áreas tradicionais da Química estão presentes como elementos estruturantes da mesma. São também consideradas estruturantes as áreas de atuação profissional destes alunos (Química Ambiental e Ensino de Química). A Bioquímica é geralmente vista como dependente de outras áreas. A Química Analítica é considerada como uma "ferramenta" a serviço das demais. O mesmo ocorre com outras áreas do conhecimento (Matemática e Física).; This work analyzes some of the activities developed within the subject of Integrated Chemical III...

Ascensão e queda dos CFCs: uma análise de periódicos científicos e de livros didáticos de química ambiental; Rise and fall of CFCs: an analysis of scientific journals and environmental chemistry textbooks

Viana, Helio Elael Bonini
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 27/08/2013 PT
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O presente trabalho tem como objetivo investigar os processos de ascensão e queda dos clorofluorocarbonetos (CFCs) como bens de consumo, bem como o desenvolvimento da percepção de risco da comunidade química em relação a esses compostos, que culminou com sua caracterização como agentes de risco ambiental global. Para isso, foi desenvolvido um estudo de caso histórico acerca do uso dos CFCs ao longo do século XX, de solução tecnológica ideal a protagonista de uma inédita dimensão de risco químico. Além disso, foi realizada uma análise de cartas enviadas por leitores, editoriais e resenhas de livros publicadas em cinco periódicos científicos: Chemical & Engineering News, Journal of Chemical Education, Environmental Science and Technology, Nature e Science, no período compreendido entre 1975 e 1991, e de livros didáticos de Química Ambiental publicados entre 1970 e 1995 - período marcado por intenso debate sobre a possibilidade de destruição da camada de ozônio estratosférica. A escolha desses periódicos e livros buscou contemplar diferentes seções da comunidade química, de modo a se ter uma amostra representativa de diferentes formas de pensamento dentro desse amplo espectro profissional que constitui a química. Para análise dessa amostra foi escolhida a Teoria Cultural de Douglas e Wildavsky...

As Representações Sociais de "QUÍMICA AMBIENTAL": contribuições para a formação de bacharéis e professores de Química; As Representações Sociais de "QUÍMICA AMBIENTAL": contribuições para a formação de bacharéis e professores de Química

Côrtes Júnior, Lailton Passos
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 14/11/2008 PT
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Esta pesquisa se propõe a investigar as representações sociais acerca do termo "Química Ambiental" entre estudantes iniciantes (segundo semestre) e depois de quatro anos em andamento nos cursos de Bacharelado em Química Ambiental e Licenciatura em Química do Instituto de Química da Universidade de São Paulo. Adotamos como referencial de investigação a Teoria das Representações Sociais e como metodologia a técnica da associação livre de palavras associada à elaboração de um texto. Os resultados foram analisados através da freqüência e ordem média de evocação das palavras para delinear o núcleo central da representação social, além dos elementos periféricos. Nos textos são identificadas unidades de análise que são utilizadas para construção de mapas cognitivos. A associação das palavras mais evocadas com as leituras dos mapas cognitivos para cada aluno proporcionou a construção de um mapa conceitual representativo da visão sobre "Química Ambiental" para cada uma das turmas analisadas. De uma forma geral, os iniciantes tanto da Licenciatura em Química como da Química Ambiental apresentaram uma visão naturalista de meio ambiente e também revelaram uma concepção de Educação Ambiental sobre o ambiente...

Avaliação ambiental de exposição a fumos metálicos em fundições; Environmental assessment of exposure to metallic fumes in foundries

Felix, Fabiana da Silva
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 17/06/2004 PT
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A Universidade de São Paulo (Instituto de Química e Faculdade de Ciências Farmacêuticas) e FUNDACENTRO têm desenvolvido um projeto nos pólos de fabricação de peças de torneiras e registros de Loanda/PR, visando a avaliação do ambiente de trabalho. Considerando as etapas do processo de fundição de latão para a confecção dos produtos, há a presença de fumos metálicos, provenientes da fundição e vazamento, que podem acarretar na intoxicação dos trabalhadores e, conseqüentemente, faz-se necessária a avaliação do risco ocupacional. Esta avaliação consiste da caracterização das partículas através da determinação de seus constituintes em massa por volume de ardo ambiente de trabalho. A concentração para particulados é expressa em µg m-3. Para isso, foi aplicada metodologia específica e reconhecida do National Institute of Organization Safety (NIOSH), a qual recomenda a utilização de espectrometria de emissão óptica com plasma acoplado indutivamente (ICP OES) para a determinação de As, Cd, Mn, Ni e Pb em amostras de ar. Foi proposta uma alternativa utilizando a voltametria de acumulação com redissolução anódica com eletrodo de gota pendente de mercúrio para a determinação de Cd e Pb...

O discurso de alunos do ensino médio a respeito da camada de ozônio

Cirino, Marcelo Maia; Souza, Aguinaldo Robinson de
Fonte: Universidade Estadual Paulista (UNESP), Faculdade de Ciências Publicador: Universidade Estadual Paulista (UNESP), Faculdade de Ciências
Tipo: Artigo de Revista Científica Formato: 115-134
POR
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O objetivo deste trabalho foi investigar os gêneros de discursos utilizados por alunos da terceira série do Ensino Médio a respeito de um dos conteúdos vinculados ao ensino de química ambiental: o estudo do gás ozônio e os problemas relacionados à degradação de sua camada na atmosfera terrestre. Os resultados apontam para um nível de envolvimento discursivo em que se percebe a apropriação da linguagem científica como ferramenta de argumentação acerca das questões ambientais.; This paper reports on a study conducted among high school students aiming to investigate their different kinds of discourse on the ozone layer depletion in environmental Chemistry classes. The final result points out the special level of speech involvement by the students and moreover we noticed the correct use of scientific discourse frameworks like argumentation related environmental questions.

Hierarchically nanostructured materials for sustainable environmental applications

Ren, Zheng; Guo, Yanbing; Liu, Cai-Hong; Gao, Pu-Xian
Fonte: Frontiers Media S.A. Publicador: Frontiers Media S.A.
Tipo: Artigo de Revista Científica
Publicado em 12/11/2013 EN
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This review presents a comprehensive overview of the hierarchical nanostructured materials with either geometry or composition complexity in environmental applications. The hierarchical nanostructures offer advantages of high surface area, synergistic interactions, and multiple functionalities toward water remediation, biosensing, environmental gas sensing and monitoring as well as catalytic gas treatment. Recent advances in synthetic strategies for various hierarchical morphologies such as hollow spheres and urchin-shaped architectures have been reviewed. In addition to the chemical synthesis, the physical mechanisms associated with the materials design and device fabrication have been discussed for each specific application. The development and application of hierarchical complex perovskite oxide nanostructures have also been introduced in photocatalytic water remediation, gas sensing, and catalytic converter. Hierarchical nanostructures will open up many possibilities for materials design and device fabrication in environmental chemistry and technology.

Catalytic nanomotors for environmental monitoring and water remediation

Soler, Lluís; Sánchez, Samuel
Fonte: Royal Society of Chemistry Publicador: Royal Society of Chemistry
Tipo: Artigo de Revista Científica
EN
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Self-propelled nanomotors hold considerable promise for developing innovative environmental applications.

Recent advances in quantitative LA-ICP-MS analysis: challenges and solutions in the life sciences and environmental chemistry

Limbeck, Andreas; Galler, Patrick; Bonta, Maximilian; Bauer, Gerald; Nischkauer, Winfried; Vanhaecke, Frank
Fonte: Springer Berlin Heidelberg Publicador: Springer Berlin Heidelberg
Tipo: Artigo de Revista Científica
EN
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Laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) is a widely accepted method for direct sampling of solid materials for trace elemental analysis. The number of reported applications is high and the application range is broad; besides geochemistry, LA-ICP-MS is mostly used in environmental chemistry and the life sciences. This review focuses on the application of LA-ICP-MS for quantification of trace elements in environmental, biological, and medical samples. The fundamental problems of LA-ICP-MS, such as sample-dependent ablation behavior and elemental fractionation, can be even more pronounced in environmental and life science applications as a result of the large variety of sample types and conditions. Besides variations in composition, the range of available sample states is highly diverse, including powders (e.g., soil samples, fly ash), hard tissues (e.g., bones, teeth), soft tissues (e.g., plants, tissue thin-cuts), or liquid samples (e.g., whole blood). Within this article, quantification approaches that have been proposed in the past are critically discussed and compared regarding the results obtained in the applications described. Although a large variety of sample types is discussed within this article...

Chemistry of carbonaceous aerosols : studies of atmospheric processing and OH-initiated oxidation

Johnson, Kirsten S. (Kirsten Sue)
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 151 p.
ENG
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Carbonaceous aerosols are among the most prevalent yet least understood constituents of the atmosphere, particularly in urban environments. We have performed analyses of field samples and laboratory studies to probe the physico-chemical properties of soot and organic aerosols in a complimentary approach to obtain information essential for understanding their atmospheric evolution and environmental effects. Samples of particulate matter < 2.5 pm in diameter (PM2.5) were collected from the Mexico City Metropolitan Area (MCMA) for both bulk compositional analysis and single particle characterization. Approximately 50% of the non-volatile component of PM2.5 was found to consist of carbonaceous material, including both soot and organics. Other major components included sulfates, soil/dust and heavy metals indicative of industrial emissions. Single particle analysis confirmed the prevalence of soot particles; our evidence suggests they quickly became internally mixed with sulfates and other inorganic compounds in a day or less through extensive processing during their atmospheric residence times. In the second half of our approach, a Quartz Crystal Microbalance - Chemical Ionization Mass Spectrometry (QCM-CIMS) system was developed to probe the OH-initiated oxidation of organic and soot thin films as atmospheric aerosol surrogates. Mass loss (volatilization) from the films was observed upon exposure to OH radicals in the presence of 02 at 295 K and 100 Torr. The loss rate was found to be linearly dependent on OH and independent of 02 concentrations over the range 02 _1012 to 2.1018 molec/cm3. A relatively slower mass loss rate in the presence of NOx suggests simultaneous formation of alkyl nitrate compounds potentially important in polluted urban environments. Experimental data were used to extract the rate constants of individual steps within the context of a previously proposed oxidation mechanism.; Volatilization was observed in 15% relative humidity at a rate slower than under dry conditions...

Photo Degradation of Cotnaminants of Emerging concern (CECs) under Simulated Solar Radiation: Implications for their Environmental Fate

Batchu, Sudha Rani
Fonte: FIU Digital Commons Publicador: FIU Digital Commons
Tipo: Artigo de Revista Científica Formato: application/pdf
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Contaminants of emerging concern (CECs) are continuously being released into the environment mainly because of their incomplete removal in the sewage treatment plants (STPs). The CECs selected for the study include antibiotics (macrolides, sulfonamides and ciprofloxacin), sucralose (an artificial sweetener) and dioctyl sulfosuccinate (DOSS, chemical dispersant used in the Deepwater Horizon oil spill). After being discharged into waterways from STPs, photo degradation is a key factor in dictating the environmental fate of antibiotics and sucralose. Photodegradation efficiency depends on many factors such as pH of the matrix, matrix composition, light source and structure of the molecule. These factors exert either synergistic or antagonistic effects in the environment and thus experiments with isolated factors may not yield the same results as the natural environmental processes. Hence in the current study photodegradation of 13 CECs (antibiotics, sucralose and dicotyl sulfosuccinate) were evaluated using natural water matrices with varying composition (deionized water, fresh water and salt water) as well as radiation of different wavelengths (254 nm, 350 nm and simulated solar radiation) in order to mimic natural processes. As expected the contribution of each factor on the overall rate of photodegradation is contaminant specific...

Identification of difficult topics in the teaching and learning of Chemistry in Irish schools and the development of an intervention programme to target some of these difficulties

Fonte: University of Limerick, Department of Chemical & Environmental Science Publicador: University of Limerick, Department of Chemical & Environmental Science
Tipo: Doctoral thesis; all_ul_research; ul_theses_dissertations; none
ENG
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non-peer-reviewed; The purpose of this investigation was to identify the topics in Chemistry that the majority of Irish pupils find difficult from Junior Certificate level right through to Third Level. It was then hoped to determine the reasons why pupils find these topics difficult. Finally it was intended to develop, implement and evaluate materials and strategies that aimed to alleviate difficulties in the learning and understanding of these topics for pupils studying Chemistry in Ireland. There were three distinct phases in this investigation. Phase one involved the development of four questionnaires: for pupils at Junior Cycle, Leaving Cycle, Leaving Certificate Chemistry teachers and third level science and engineering students. These questionnaires consisted of a list of the different Chemistry topics studied at each level attached to a Likert scale, which asked pupils to give their opinion on the level of difficulty of the Chemistry topics. The views of practicing Chemistry teachers were also sought as to the topics they think students find most difficult. Findings from this phase of the investigation indicate that pupils have difficulty with the majority of topics in the different Chemistry courses, and that these difficulties persist from Junior Certificate level right through to third level education. Phase two of this investigation involved the development and implementation of instruments that would determine why those studying Chemistry find these topics difficult. The instrument was a pen and paper tool and was fashioned to assess the cognitive development of Irish pupils and also to determine the type of chemical misconceptions Irish pupils possess about the difficult Chemistry topics identified in phase one of the investigation. The literature has identified the areas of cognitive development and alternative conceptions (misconceptions) as having a major effect on how easy or difficult pupils find Chemistry topics. Results from phase two indicate that the majority of pupils/students in this study were operating at the concrete operational stage of cognitive development and that they possessed many Chemical misconceptions relating to fundamental Chemistry topics such as the Mole and the Particulate Nature of Matter. Phase three of this investigation involved the development...

Monitoramento atmosférico passivo de SO2, NO2 e O3 em áreas urbanas e de influência industrial como prática de química ambiental para alunos de graduação

Campos,Vânia P.; Cruz,Lícia P. S.; Alves,Eagles M.; Santos,Tatiane de S.; Silva,Adriano D.; Santos,Ana C. C. dos; Lima,Angelo M. V.; Paixão,Carine S.; Santos,Daniele C. M. B.; Brandão,Denise S.; Andrade,Elisângela J. S.; Moreira Jr.,José I.; Concei
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/07/2006 PT
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This study is a result of undergraduate student participation in the Environmental Chemistry discipline provided by the Chemistry Institute/UFBA. The students were involved in the development of passive samplers, a project of the LAQUAM (Environmental Analytical Chemistry Laboratory). The students' residences and other neighborhoods were used to create a passive sampling network, allowing the measurement of atmospheric levels of pollutants in urban areas and in those under industrial influence. The assembly of the passive samplers, including impregnation of filters and chemical analysis were part of the students' practice tasks. The results were analyzed taking into consideration the Brazilian legislation.

A Química Ambiental no Brasil

Mozeto,Antonio A .; Jardim,Wilson de F.
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/05/2002 PT
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Defining environmental chemistry is a not an easy task because it encompasses many different topics. According to Stanley E. Manahan, author of a classical textbook of Environmental Chemistry, this branch could be defined as the one centered in the study of the sources, transport, effects and fates of chemical species in the water, soil, and air environments, as well as the influence of human activity upon these processes. More recently, new knowledge emerged from the Environmental Toxicology allowed to go even deeper in the meaning of 'effects' and 'fates' of a continuous growing number of organic and inorganic species disposed in water bodies, soils and atmosphere. Toxicity tests became an important tool to evaluate the environmental impact of such species to a great number of organisms, thus allowing to set quality criteria for drinking water, sediments and biota. The state of art shows that environmental chemistry is a multi-inter disciplinary science by nature; therefore, it needs more than a limited, unique-approach and non-oriented set of data to understand the nature of natural processes. Taking all these aspects into consideration, one can say that Environmental Chemistry in Brazil is now a well established area of research within the classical areas of the Chemistry...

First-principles density functional theory study of sulfur oxide chemistry on transition metal surfaces; 1st-principles density functional theory study of sulfur oxide chemistry on transition metal surfaces

Lin, Xi, 1973-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 310 p.; 9412825 bytes; 9412627 bytes; application/pdf; application/pdf
ENG
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In this thesis, the chemistry of sulfur oxides on transition metals is studied extensively via first-principles density functional theory (DFT) computations, focusing on the chemical reactivity and selectivity in sulfur poisoning chemical processes that address environmental concerns. The systematic approach we establish can be extended to general computational studies of small gas-phase molecules interacting with extended surfaces or finite-size clusters. The thesis starts with a theoretical presentation of modem quantum many-body theory that brings together mean-field theory, DFT, and Green's function quantum Monte Carlo theory. The essence of chemical reactivity theory in the framework of DFT is emphasized. The thesis continues with an extensive survey of the current status of sulfur oxide chemistry and an overall presentation of our computational approaches towards a detailed understanding of chemical reactivity and selectivity. The basic guidelines in chemical reactivity are systematically constructed by computed comprehensive thermodynamic data of surface S, O, SO, SO2, SO3, and S04 species as a function of coverage at low and intermediate temperatures. Under these basic guidelines, experimentally measured surface spectra are interpreted...

An Emerging Picture of Neoproterozoic Ocean Chemistry: Insights from the Chuar Group, Grand Canyon, USA

Johnston, David T; Poulton, Simon W.; Dehler, Carol; Porter, Susannah; Husson, Jon; Canfield, Donald E.; Knoll, Andrew Herbert
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
EN_US
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Detailed iron, sulfur and carbon chemistry through the > 742 million year old ChuarGroup reveals a marine basin dominated by anoxic and ferrous iron-rich (ferruginous) bottom waters punctuated, late in the basin's development, by an intrusion of sulfide-rich (euxinic) conditions. The observation that anoxia occurred frequently in even the shallowest of Chuar environments (10s of meters or less) suggests that global atmospheric oxygen levels were significantly lower than today. In contrast, the transition from ferruginous to euxinic subsurface water is interpreted to reflect basinal control—specifically, increased export of organic carbon from surface waters. Low fluxes of organic carbon into subsurface water masses should have been insufficient to deplete oxygen via aerobic respiration, resulting in an oxic oxygen minimum zone (OMZ). Where iron was available, larger organic carbon fluxes should have depleted oxygen and facilitated anaerobic respiration using ferric iron as the oxidant, with iron carbonate as the expected mineralogical signature in basinal shale. Even higher organic fluxes would, in turn, have depleted ferric iron and up-regulated anaerobic respiration by sulfate reduction, reflected in high pyrite abundances. Observations from the ChuarGroup are consistent with these hypotheses...

Social Ecology of Children’s Vulnerability to Environmental Pollutants

Weiss, Bernard; Bellinger, David C.
Fonte: National Institute of Environmental Health Sciences Publicador: National Institute of Environmental Health Sciences
Tipo: Artigo de Revista Científica
EN_US
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Background: The outcomes of exposure to neurotoxic chemicals early in life depend on the properties of both the chemical and the host’s environment. When our questions focus on the toxicant, the environmental properties tend to be regarded as marginal and designated as covariates or confounders. Such approaches blur the reality of how the early environment establishes enduring biologic substrates. Objectives: In this commentary, we describe another perspective, based on decades of biopsychological research on animals, that shows how the early, even prenatal, environment creates permanent changes in brain structure and chemistry and behavior. Aspects of the early environment—encompassing enrichment, deprivation, and maternal and neonatal stress—all help determine the functional responses later in life that derive from the biologic substrate imparted by that environment. Their effects then become biologically embedded. Human data, particularly those connected to economically disadvantaged populations, yield equivalent conclusions. Discussion: In this commentary, we argue that treating such environmental conditions as confounders is equivalent to defining genetic differences as confounders, a tactic that laboratory research, such as that based on transgenic manipulations...

Environmental risk assessment of pharmaceutical residues in wastewater effluents, surface waters and sediments

Hernando, María Dolores; Mezcua, M.; Fernández Alba, Amadeo R.; Barceló, Damià
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 19968 bytes; application/msword
ENG
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9 pages, 2 tables, 2 figures.-- PMID: 18970571 [PubMed].-- Available online Nov 18, 2005.-- Issue title: "1st Swift-WFD workshop on validation of Robustness of sensors and bioassays for Screening Pollutants" (Maó, Menorca, Dec 2-3, 2004).; Pharmaceutical residues in the environment, and their potential toxic effects, have been recognized as one of the emerging research area in the environmental chemistry. The increasing attention, on pharmaceutical residues as potential pollutants, is due that they often have similar physico-chemical behaviour than other harmful xenobiotics which are persistent or produce adverse effects. In addition, by contrast with regulated pollutants, which often have longer environmental half-lives, its continuous introduction in the environment may make them “pseudopersistents”.; Pharmaceutical residues and/or their metabolites are usually detected in the environment at trace levels, but, even that, low concentration levels (ng/L or μg/L) can induce to toxic effects. In particular, this is the case of antibiotics and steroids that cause resistance in natural bacterial populations or endocrine disruption effects.; In this study, an overview of the environmental occurrence and ecological risk assessment of pharmaceutical residues is presented from literature data. Risk Quotient method (RQ) was applied as a novel approach to estimate the environmental risk of pharmaceuticals that are most frequently detected in wastewater effluents...

Sustainability and Environmental Chemistry in Semi-Arid/Arid Regions: A Unique Research Opportunity with Global Implications

Sierra Rayne
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Conferência ou Objeto de Conferência
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Dr. Sierra Rayne will be speaking on the interplay of sustainability and environmental chemistry in semi-arid and arid regions worldwide. Drawing on his previous, current, and proposed research on organic and inorganic contaminants in aquatic systems, Dr. Rayne will illustrate the importance of multidisciplinary and interdisciplinary approaches towards tackling environmental problems. A key element of his work is looking at chemical dynamics in environmental matrices, and in particular, photochemically generated reactive intermediates and their impact on biological systems and net ecosystem functions. Semi-arid/arid regions also offer unique opportunities to focus on the role of photochemistry in the biogeochemical cycling of oxyanion-forming heavy metals such as arsenic, molybdenum, selenium, and uranium (among others). Given the importance of semi-arid/arid regions in hosting major mineral deposits, multidisciplinary environmental chemistry research can also help make contributions towards sustainability in the worldwide mining industry. These fields offer great opportunities for researchers and students interested in semi-arid/arid landscapes, and understanding the role and impact of these regions on global contaminant fluxes is at the core of Dr. Rayne’s program.

An inquiry-based practical curriculum for organic chemistry as preparation for industry and postgraduate research

Pilcher,Lynne A.; Riley,Darren L.; Mathabathe,Kgadi C.; Potgieter,Marietjie
Fonte: South African Journal of Chemistry Publicador: South African Journal of Chemistry
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2015 EN
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This paper describes the development of a new practical curriculum for third-year organic chemistry to replace the recipe-based approach typically used in undergraduate teaching laboratories. The new curriculum consists of an inquiry-based project set in a simulated industrial context preceded by two scaffolding experiments to prepare students for the task. The industrial project requires students to evaluate experimentally three multi-step synthetic routes to a given target based on cost, technical challenge and environmental impact in order to make a recommendation as to which route the 'company' should use to synthesize the compound. The project equips students with technical skills suitable for both postgraduate research and industry, and develops metacognition and understanding through the use of the jig-saw cooperative learning strategy and reflection. The students were found to engage with the practical work at a deep intellectual level, demonstrating that contextualized inquiry-based laboratory teaching afforded an improved quality of learning. In addition, the reported practical curriculum made a difficult subject accessible and even popular, to some measure grew the students' ability in all desired graduate attributes and resulted in the establishment of a professional identity for individual students.