José Roberto Caetano da Rocha (original) (raw)

Papers by José Roberto Caetano da Rocha

World Journal of Advanced Engineering Technology and Sciences

Rivers are widely used by societies and have been degraded due to environmental impacts caused by... more Rivers are widely used by societies and have been degraded due to environmental impacts caused by human action over the years. This factor influences the extinction or decrease of the biological diversity of rivers and nearby regions. The anthropization on the rivers in the coastal region of Paraná causes impacts that can be evaluated through physical-chemical parameters of the local water resources. The objective of this work was to quantify the concentration of phosphate, ammonia and nitrate ions present in water samples from the Santa Cruz River and the Ribeirão River (Paranaguá - PR), which are crossed by PR 508 - Alexandra - Matinhos. The space-time sample collection took place in March and September of the year 2020. The values of turbidity, air and water temperature, concentration of phosphate, ammonia and nitrate ions were evaluated, in addition to the measurement of pH values, dissolved oxygen, electrical conductivity, total dissolved solids, in the four sampling points, be...

O Programa Paranaense de Certificacao de Produtos Orgânicos foi implantado em 2009 pelo governo d... more O Programa Paranaense de Certificacao de Produtos Orgânicos foi implantado em 2009 pelo governo do Parana tendo como objetivo principal consolidar o estado como um importante produtor de orgânicos do pais, fornecendo certificacao gratuita a pequenos produtores rurais de orgânicos, bem como fomentando inovacoes tecnologicas e o cooperativismo/associativismo. Atualmente e executado por um convenio entre oito instituicoes de ensino superior, pelo Centro Paranaense de Referencia em Agroecologia e Instituto de Tecnologia do Parana. Na regiao litorânea e conduzido pela Unespar, onde docentes, profissionais recem-formados e estudantes graduandos bolsistas visitam pequenas propriedades e desenvolvem estudos de caso, procurando adequar as mesmas a legislacao e normatizacoes pertinentes, alem de capacitar produtores familiares para a producao de orgânicos. Nesta segunda fase, iniciada em junho de 2012, espera-se certificar, no minimo, 50 pequenas propriedades nos sete municipios da regiao.

Periódico Tchê Química, 2014

In this work the results of spectrophotometric assays performed on samples taken from the waters ... more In this work the results of spectrophotometric assays performed on samples taken from the waters of ownership of organic products, located in the municipality of Paranaguá, as well as other physical and chemical testing of these samples are presented. They were conducted to evaluate the tissue property. The spectrophotometric assays were performed to quantify the chemical element phosphorus by the molybdenum blue method and nitrogen chemical element methods by Griess and Indophenol. These chemicals have low natural availability and macronutrients are important for the growth of plants. With the results it was found that the concentrations of the element nitrogen are below the limits specified by Resolution 357/2005 of CONAMA. Have phosphate ions showed higher concentrations in the water samples were taken from two specific points of organic property. In the samples from the first sampling point was observed that the levels of phosphate present were higher than the results obtained f...

Neste trabalho são apresentados resultados da eletrodeposição de MoOx e de WOx em eletrodos de ca... more Neste trabalho são apresentados resultados da eletrodeposição de MoOx e de WOx em eletrodos de carbono vítreo e em eletrodos de ouro. A estabilidade de filmes de WOx foi investigada em diferentes valores de pH utilizando voltametria cíclica e microbalança eletroquímica de cristal de quartzo e observou-se que estes filmes são estáveis em soluções com valores de pH inferiores a 3. O processo eletrocatalítico envolvendo a redução de IO3- em superfícies recobertas com WOx foi comparado com aquele observado em eletrodo modificado com MoOx, observando-se as vantagens deste processo em superfícies modificadas com WOx. Discutiram-se ainda os resultados obtidos do processo da oxidação de óxido nítrico na superfície eletródica polida e modificada com WOx. Também são apresentados resultados de estudos comparativos sobre a redução do IO3-, BrO3- e ClO3- na superfície modificada, concluindo-se que no caso do IO3- obtêm-se maiores valores de corrente devido à maior polarizabilidade do átomo de io...

Periódico Tchê Química, 2017

In this study evaluated the knowledge that elementary school students have about the environment ... more In this study evaluated the knowledge that elementary school students have about the environment and about the process of separating the solid waste produced daily in their homes. This research was carried out with students of the 7th, 8th and 9th years of a state school located in the city of Paranaguá, PR. In it we considered some preventive measures that could alleviate the problem caused by the inadequate disposal of these materials and if they can observe some economic value in the solid waste produced. Thus, the main objectives were the questioning about the amount of solid waste produced in their homes. Evaluate if people perform the selective separation of the same. In addition to quantify and know the final destination of solid waste produced daily by them. Through the methodology used it was noticed that even the questionnaire being applied in different series of elementary school the answers presented showed little variation from one class to another. Therefore even in su...

Nesse trabalho são apresentados os resultados dos ensaios espectrofotométricos realizados nas amo... more Nesse trabalho são apresentados os resultados dos ensaios espectrofotométricos realizados nas amostras retiradas das águas do Rio Guaraguaçú localizado no litoral Paranaense. Esses ensaios foram realizados para quantificar o elemento fósforo pelo método do azul de molibdênio e o elemento nitrogênio pelos métodos de Griess e indofenol. Com esses resultados foi possível avaliar que o referido rio vem sofrendo com a atividade antrópica no seu entorno. Os resultados de fosfato estão acima dos valores estabelecidos pela Resolução 357/2005 do CONAMA, sendo que esses resultados, quando comparados com os obtidos em outro rio da região, são similares, daí observa-se que esse fato não é provocado por atividade antrópica. Já os resultados das concentrações dos íons amônio, nitrato e nitrito indicam que os valores obtidos estão abaixo dos valores máximos estabelecidos pela referida resolução, denota-se então que a presença desses dois últimos íons em águas superficiais ocorre onde a atividade antrópica está em expansão. Palavras-chave: nutrientes fosfatados; nutrientes nitrogenados; contaminação antrópica; determinação espectrofotométrica.

Periódico Tchê Química, 2012

The present study evaluated the process of solution preparation, which is defined as a system pre... more The present study evaluated the process of solution preparation, which is defined as a system presenting different substances, but with the same chemical composition and physical properties in all points of the solution. This type of system is very important, especially for chemistry, since the water has the ability to dissolve a wide variety of aqueous solutions forming substances which facilitate the reactive processes in nature, as well in all living cells. Thus, the factors related to this physical process of dissolution were considered in order to become the process more didactic, and consequently, more accessible to a wider cognitive range. Copper II sulphate pentahydrate in water was used as target chemical substance in this study. This solid compound has strong blue color, and when in solution with several and different concentrations are achieved the required color gradient which helps the future educators of the discipline of chemistry to demonstrate the influence of the a...

In this work the analytical results of water samples taken from Itiberê River and its affluent Vi... more In this work the analytical results of water samples taken from Itiberê River and its affluent Village River are presented. The settlement of Paranaguá occurred, among other places, along these two rivers, which caused deforestation of Atlantic Forest areas for residential construction and commerce in general. To evaluate this environmental impact, analytical tests were carried out in which the nitrogen and phosphorus macronutrients, considered the eutrophic agents, were quantified as well as other physical and chemical parameters such as pH, turbidity and the total residue. For that, we used the potentiometric, turbidimetric, gravimetric and spectrophotometric analytical techniques. These analytical results showed that in some sample points the degradation process is relatively high due to the alteration of pH values and ammonium ion. The excessive presence of the phosphate ion in some sample points, that is, values close to 40 times higher than the values recommended in CONAMA Res...

Os rios sao ecossistemas aquaticos funcionais e extremamente essencias para o equilibrio do meio ... more Os rios sao ecossistemas aquaticos funcionais e extremamente essencias para o equilibrio do meio ambiente. Alem de garantir fonte de renda atraves do extrativismo de organismos para consumo, tambem e utilizado para o turismo. Porem, os rios sao ambientes que sofrem drasticamente devido acoes antropicas, pois sofrem com as alteracoes das concentracoes de substâncias quimicas, tornando-os poluentes ambientais. O nitrogenio se apresenta em varias especies quimicas, sendo que o nitrato e a sua forma mais oxidada e portanto mais estavel. Alem de ser a especie mais facil de assimilacao por parte dos vegetais durante o processo de crescimento. Esse ion, normalmente, e encontrado em baixas concentracoes em recursos hidricos. Porem com o excessivo uso de fertilizantes nos solos, devido aos descartes domesticos e industriais, nos recursos hidricos tende a haver o aumento da concentracao desse ion. Orgaos ambientais estabelecem que a concentracao desse ion nao pode exceder a 10mg. L -1 de N-NO...

O Rio Peri e o unico afluente localizado na margem esquerda do Rio Guaraguacu. A confluencia dess... more O Rio Peri e o unico afluente localizado na margem esquerda do Rio Guaraguacu. A confluencia desses dois rios ocorre no municipio de Pontal do Parana na Latitude 25o41’48’’ S e Longitude 48o31’07’’ W. Proximo as margens do Rio Peri esta localizado o Lixao do municipio de Pontal do Parana onde sao recolhidos diariamente todos os residuos produzidos pela populacao local, bem como pela populacao flutuante composta pelos turistas que chegam ao municipio nos periodos denominados de alta temporada. Desta forma os dois rios sofrem com essa influencia antropica, que e o deposito de lixo a ceu aberto. O presente trabalho tem como principal objetivo avaliar o teor de nutrientes nitrogenados e fosfatados em suas formas ionicas (nitrato, amonio e fosfato). Alem de avaliar outras caracteristicas fisico-quimicas como pH, turbidez e residuo dissolvido, de oito pontos amostrais em dois periodos distintos do ano (alta e baixa temporada). Os ensaios de pH foram realizados apos o aparelho ser calibrad...

This study presents the results of chemical and physical determinations carried out on samples ta... more This study presents the results of chemical and physical determinations carried out on samples taken from the waters of the Pery River, one of the tributaries of the Guaraguaçu River. This body of water is located on the coast of Paraná, nearby the "Dumping Ground" of the city of Pontal do Paraná. The concentrations of phosphate and nitrogenous nutrients present at the site were determined, as well as other physico-chemical characteristics such as pH, turbidity and dissolved solid residue. The methodology used for the quantification of phosphorus was molybdenum blue. Yet, for the quantification of the nitrogen in the form of the ammonium ion, the indophenol blue method was used. For the determination of the nitrogen in the form of the nitrate ion the Griess method was used, then the reduction of nitrate to nitrite. The evaluation of the results were performed based on the values established by the Brazilian legislation, through Resolution 357/2005 of CONAMA, where it was n...

28a. Reunião Anual da SBQ, 2005

Journal of Electroanalytical Chemistry, 2002

Molecular interfaces constituted by electrostatically assembled tetraruthenated cobaltporphyrin (... more Molecular interfaces constituted by electrostatically assembled tetraruthenated cobaltporphyrin (Co(TRP)) and tetrasulphonated zincporphyrin (Zn(TPPS)) multi-bilayer films, have been recently exploited for the development of sensors and electrochemical devices. In this work, their conducting properties were investigated by means of cyclic and rotating disk voltammetry, and by impedance spectroscopy. The films exhibited an unusually high conductivity, which increased further when the potential approached the redox potential of the Ru(III/II) couple. This behavior is reflected in a very low heterogeneous charge transfer resistance, leading to Nyquist diagrams dominated by or exhibiting solely a wide Warburg region. The kinetics of a previously reported analytical
application involving heterogeneous charge transfer from nitrite ions to the porphyrin film interface was carefully examined. According to this study, the limiting step for the nitrite oxidation is the heterogeneous charge transfer to the interfacial Ru(III) complexes, with k /2.7 /103 dm3 mol 1 s 1.

Química Nova na Escola, 2005

Este trabalho apresenta uma alternativa de procedimento pedagógico para trabalhar os conceitos: á... more Este trabalho apresenta uma alternativa de procedimento pedagógico para trabalhar os conceitos: átomo, molécula, elemento químico, substância simples e substância composta. Esse procedimento foi realizado para turmas da primeira série do Ensino Médio de uma escola pública paulistana. Também são comentados os resultados das avaliações realizadas para quantificar o grau de conhecimento que os alunos conseguiram reter após a utilização do referido procedimento pedagógico.

Cadernos de Agroecologia, 2014

Nesse trabalho sao descritas as principais diretrizes e fundamentacao da segunda fase do Programa... more Nesse trabalho sao descritas as principais diretrizes e fundamentacao da segunda fase do Programa Paranaense de Certificacao de Produtos Orgânicos (PPCPO – Fase II), bem como esse programa surgiu e como ele e mantido financeiramente. Posteriormente realizou-se a avaliacao dos estudos de casos realizados no Assentamento Nhundiaquara - Gleba Pantanal localizado no municipio de Morretes, no litoral paranaense. Nessa avaliacao e discutida a historia desse assentamento, assim como se relatam as caracteristicas, potencialidades e dificuldades observadas durante o processo avaliativo que antecede o encaminhamento ao Instituto de Tecnologia do Parana (TECPAR). Durante esse processo de visitas e estudos de caso se percebeu que os proprietarios rurais necessitavam desse processo de Assistencia Tecnica e Extensao Rural (ATER) realizado pelos tecnicos do PPCPO – Litoral, para que os produtores rurais compreendessem a possivel certificacao dos mesmos.

International Journal of Advanced Engineering Research and Science

Rivers always went too utilized for the population’s benefits, however, environmental impacts cau... more Rivers always went too utilized for the population’s benefits, however, environmental impacts caused by humans have resulted in aquatic ecosystems degradation. This fact decreases biological diversity and impairs water availability. Amongst elements which could be quantified to evaluate the impact caused anthropically are phosphorus and nitrogen since the increase of their levels in rivers could result in artificial eutrophication. Thus, the aim of this work was to evaluate the Peri River (Pontal do Paraná – PR) in a spacetime perspective, between 2018 and 2019. It was measured the pH, dissolved oxygen, electric conductivity, total dissolved solids, turbidity, air and water temperature, phosphorus, nitrate, and ammonium in 8 samples points. The majority of the parameters got compatible values with the established with 357/2005 CONAMA’s resolution, even the results of the ammonia ion in May 2019 in the points 1, 2, 3, and 4 have shown high values, likely as consequence as leachate from the dump. The parameter pH in point 8, localized in the river source has shown acid values due to soil leaching or the introduction of chemical substances adjacent to this place. As well as past studies, phosphorus has been showing elevated values, which in this set sample collections, data are 50 folds higher than to the established by the CONAMA’s resolution, making the Peri River susceptible to eutrophication and environmental deterioration. We concluded that Peri River has been suffering gradually with anthropic impacts, thus, preventive and palliative actions must be taken immediately against the anthropic actions.