Développement de catalyseurs hétérogènes pour la photodégradation du néonicotinoïde acétamipride dans l'eau

En raison de l'utilisation généralisée de l'acétamipride dans de nombreuses régions et de ses résidus potentiels présents dans l'environnement, ce néonicotinoïde a reçu une attention considérable de la part de la communauté scientifique en quête active de méthodes efficaces assurant sa dégradation. Au cours des dernières décennies, la photocatalyse hétérogène et l'application des semi-conducteurs ont été largement étudiées pour la dégradation des polluants organiques. Cette thèse vise à développer des photocatalyseurs efficaces à base d'oxyde de zinc (ZnO), en appliquant différentes stratégies, telles que le couplage de ZnO avec des métaux et des non-métaux permettant de réduire les inconvénients possibles, tels que la recombinaison électron-trou et d'étendre l'absorption de la lumière dans le domaine du visible. Dans les études réalisées dans le cadre de la présente thèse, il a été proposé la production de photocatalyseurs par la méthode de précipitation simple et la précipitation assistée par microondes, avec dopage et co-catalyse de matériaux métalliques (Ce, Cu, Fe, Pd) et non métalliques (N et oxyde de graphène). Les différents nanomatériaux catalytiques synthétisés ont été caractérisés afin d'évaluer leur morphologie, leur structure et leurs propriétés optiques et texturales. Les photocatalyseurs ont par la suite été appliqués au processus de réaction de photocatalyse hétérogène sous la lumière visible pour la dégradation de l'acétamipride dans l'eau. Les photocatalyseurs dopés simultanément à l'azote et à l'oxyde de graphène ainsi qu'au palladium et à l'oxyde de graphène ont donné des résultats les plus prometteurs en assurant la dégradation totale de l'acétamipride au bout de 300 min à la température ambiante. Par ailleurs, afin d'améliorer les performances de dégradation du polluant, le recours aux ultrasons a été mis en œuvre de deux méthodes différentes. La première consistait à utiliser les ultrasons comme prétraitement avant la photocatalyse. La deuxième consistait en une combinaison simultanée de la cavitation ultrasonore et de la photocatalyse hétérogène. Cette dernière stratégie s'est avérée la plus efficace en permettant d'assurer une dégradation complète de l'acétamipride au bout de 120 min de réaction sonophotocatalytique. En conclusion, la présente recherche s'est révélée positive, répondant à l'objectif principal de dégradation de l'acétamipride dans l'eau, en utilisant des procédés innovants dans le domaine de la photocatalyse, qui sont simples et faciles à appliquer et à manipuler.Due to the widespread use of acetamiprid in many regions worldwide and its potential residues in the environment, this neonicotinoid has received considerable attention from the scientific community actively seeking effective methods to ensure its degradation. In recent decades, heterogeneous photocatalysis and the application of semiconductors have been widely studied for the degradation of organic pollutants. The present thesis aims to develop efficient photocatalysts based on zinc oxide (ZnO), by applying different strategies, such as the coupling of ZnO with metals and non-metals allowing to reduce the possible drawbacks, such as electron recombination -hole and extend the absorption of light to the visible range. In the investigations carried out within the framework of this thesis, it was proposed the production of photocatalysts by the simple precipitation method and the precipitation assisted by microwaves, with doping and co-catalysis of metallic materials (Ce, Cu, Fe, Pd) and non-metallic (N and graphene oxide). The different catalytic nanomaterials synthesized were characterized to evaluate their morphology, structure, optical and textural properties. The photocatalysts were subsequently applied to the heterogeneous photocatalysis reaction process under visible light irradiation for the degradation of acetamiprid in water. Photocatalysts doped simultaneously with nitrogen and graphene oxide as well as palladium and graphene oxide have given the most promising results by ensuring the complete degradation of acetamiprid after 300 min of reaction at ambient temperature. Furthermore, to improve the pollutant degradation performances, the use of ultrasound was implemented in two different methods. The first was to use ultrasonication as a pretreatment before photocatalysis. The second consisted of a simultaneous combination of ultrasonic cavitation and heterogeneous photocatalysis. The latter strategy has proven to be the most effective in ensuring complete degradation of acetamiprid after 120 min of sonophotocatalytic reaction. In conclusion, the present research was shown to be positive, meeting the main objective of degradation of acetamiprid in water, using innovative processes in the field of photocatalysis, which are simple and easy to apply and manipulate

Dimensionamento de sistemas eólicos no entorno geográfico do município de Marechal Cândido Rondon

A crescente preocupação em torno das questões ambientais e devido aos impactos causados pelas formas tradicionais de geração de energia advindas de fontes fósseis, vários países vêm investindo na introdução de fontes alternativas de energia. Vários setores da sociedade brasileira notaram a necessidade do uso racional e diversificação das fontes de energia elétrica. O desenvolvimento da energia eólica dentro do Brasil tem se destacado como geração complementar de energia limpa. Desta forma, para a instalação de parques eólicos, é interessante observar as características meteorológicas do local de instalação e equipamentos para que a eficiência energética do sistema seja a melhor possível. Com o intuito de instalar um projeto de turbina eólica na cidade de Marechal Candido Rondon buscou-se dados literários para se obter os valores característicos do local como altitude e velocidade dos ventos. A partir desses dados foi possível avaliar o potencial eólico de 3 cenários e em cada um deles foi avaliada o quanto de energia pode ser gerada em kWh/mês. Com os resultados obtidos foi estudada a hipótese de suporte para uma residência de pequeno porte com o gasto total mensal de 330 kWh/mês. No presente trabalho, não obtivemos uma boa viabilidade, devido ao teor dos ventos de Marechal Candido Rondon ser muito baixo atingindo no máximo 55,2 KWh/mês, necessitando de no mínimo 6 turbinas para sustentar a residênci

ANÁLISE DA QUALIDADE DO CARVÃO PARA CONSUMO DOMÉSTICO DE QUATRO MUNICÍPIOS DO ESTADO DO PARANÁ

Neste trabalho, objetivou-se verificar a origem, o teor de umidade, teor de carbono fixo, teor de materiais voláteis, teor de cinzas e o poder calorífico superior de diferentes marcas de carvões vegetais comercializadas e comparar com os padrões exigidos pelo Selo Premium – SP. As análises foram realizadas com oito amostras de carvão vegetal adquiridas em estabelecimentos comerciais nos municípios paranaenses de Palotina, Altônia, Toledo e Ouro Verde do Oeste. Quanto a origem, cinco são de carvões vegetais oriundos do Paraguai, as demais amostras têm origem no Estado do Paraná. Todas as amostras possuem registro no IBAMA e são de madeiras de reflorestamento ou exóticas. O teor de umidade determinado foi de 4,02 – 7,77%, o teor de carbono fixo de 53,94 - 81,06%, o teor de materiais voláteis de 14,53 – 40,70% e o teor de cinzas de 2,96 - 18,11% e o poder calorifico superior  de 22584,0 J/g - 31166,5 J/g. Os valores determinados são condizentes com aqueles encontrados na literatura no entanto, nenhuma marca cumpriria as exigências do Selo Premium totalmente

Palladium and Graphene Oxide Doped ZnO for Aqueous Acetamiprid Degradation under Visible Light

Acetamiprid is a neonicotinoid insecticide widely used in pest control. In recent years, it has been considered as a contaminant in groundwater, lakes, and rivers. Photocatalysis under visible light radiation proved to be an effective process for getting rid of several organic pollutants. In the present work, photodegradation of aqueous acetamiprid was investigated over bare zinc oxide (ZnO) photocatalyst as well as ZnO doped with either palladium or palladium combined with graphene oxide. Both ZnO and doped-ZnO were synthesized via a microwave-assisted hydrothermal procedure. The obtained photocatalysts were characterized using different techniques. After 5 h of reaction at ambient temperature under visible light irradiation, acetamiprid conversions attained ca. 38, 82, and 98% in the presence of bare ZnO, Pd-doped ZnO and Pd-GO-doped ZnO photocatalysts, respectively, thus demonstrating the positive effect of Pd- and GO-doping on the photocatalytic activity of ZnO. In addition, Pd-GO-doped ZnO was shown to keep its activity even when it is recycled five times, thus proving its stability in the reaction medium

Palladium and Graphene Oxide Doped ZnO for Aqueous Acetamiprid Degradation under Visible Light

Acetamiprid is a neonicotinoid insecticide widely used in pest control. In recent years, it has been considered as a contaminant in groundwater, lakes, and rivers. Photocatalysis under visible light radiation proved to be an effective process for getting rid of several organic pollutants. In the present work, photodegradation of aqueous acetamiprid was investigated over bare zinc oxide (ZnO) photocatalyst as well as ZnO doped with either palladium or palladium combined with graphene oxide. Both ZnO and doped-ZnO were synthesized via a microwave-assisted hydrothermal procedure. The obtained photocatalysts were characterized using different techniques. After 5 h of reaction at ambient temperature under visible light irradiation, acetamiprid conversions attained ca. 38, 82, and 98% in the presence of bare ZnO, Pd-doped ZnO and Pd-GO-doped ZnO photocatalysts, respectively, thus demonstrating the positive effect of Pd- and GO-doping on the photocatalytic activity of ZnO. In addition, Pd-GO-doped ZnO was shown to keep its activity even when it is recycled five times, thus proving its stability in the reaction medium

Conscientização ambiental uma integração sociedade e meio ambiente para reciclagem do óleo residual

O objetivo do presente trabalho foi proporcionar a conscientização da população do município de Palotina- PR, a partir da apresentação dos impactos ambientais provocados pela disposição incorreta do óleo residual de fritura. Foram realizadas palestras educacionais em dois colégios estaduais do município, apresentando os prejuízos ambientais causados pela disposição inadequada de tais resíduos, e a forma correta de disposição, e suas possíveis aplicações. Percebe-se que a conscientização na população em relação ao óleo como poluente merece uma atenção maior, pois muitas pessoas não têm o conhecimento de que pouca quantidade de óleo pode poluir centenas de litros de água. Observamos com os resultados do questionário que a maior parte das crianças sabem do descarte correto, porém não se pode afirmar que as mesmas realizam o descarte correto