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.
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.
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