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Production of catalysts for the valorization of plastic waste, and for the wet peroxide oxidation of paracetamol

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Resumo:The efficient treatment of waste plastics and pharmaceutical pollutants is of conspicuous environmental, social and economic benefits. Therefore, here it is approached the application of catalysts that can be efficient in mitigating both environmental problems. In this work, four different catalysts were prepared. Three of them were synthesized by co-precipitation of Ni, Al and Fe nitrates with different mass ratios (5%Ni:95%Al, 20%Ni:80%Al and 10%Ni10%Fe80%Al). The fourth catalyst was prepared by wet impregnation of nickel on alumina. Then fresh catalysts were characterized by Fourier Transformed Infrared Spectroscopy and X-ray diffraction to observe crystalline phases. Carbon structures were prepared from low-density polyethylene, used as representative compound of plastic solid waste by Chemical Vapor Deposition over 20% Ni/Al catalyst in a tubular furnace. Scanning Electron Microscopy analyses were performed, identifying the carbon nanostructures with size variation (1 μm to 4 μm). For paracetamol (PCM) removal Catalytic Wet Peroxide Oxidation was assessed with 20%Ni:80%Al, 10%Fe:10%Ni:80% and commercial Al2O3 catalysts. The conversion of paracetamol, hydrogen peroxide and Total Organic Carbon (TOC) were monitorized by High-Performance Liquid Chromatography, UV-Vis spectrophotometer and TOC analyzer, respectively. The iron-containing catalyst showed the highest catalytic activity in the CWPO of PCM satisfactory conversions (complete removal of PCM after 4 h of reaction time under the following operating conditions: Ccat = 2.5 g/L, CPCM,0 = 100 mg/L, pH0 = 3.5, and CH2O2 = 472.4 mg/L).
Autores principais:Silva, Ana P. F.
Assunto:Environmental applications Plastics solid waste Upcycling Paracetamol Carbon nanotubes Catalytic wet peroxide oxidation
Ano:2020
País:Portugal
Tipo de documento:dissertação de mestrado
Tipo de acesso:acesso aberto
Instituição associada:Instituto Politécnico de Bragança
Idioma:inglês
Origem:Biblioteca Digital do IPB
Descrição
Resumo:The efficient treatment of waste plastics and pharmaceutical pollutants is of conspicuous environmental, social and economic benefits. Therefore, here it is approached the application of catalysts that can be efficient in mitigating both environmental problems. In this work, four different catalysts were prepared. Three of them were synthesized by co-precipitation of Ni, Al and Fe nitrates with different mass ratios (5%Ni:95%Al, 20%Ni:80%Al and 10%Ni10%Fe80%Al). The fourth catalyst was prepared by wet impregnation of nickel on alumina. Then fresh catalysts were characterized by Fourier Transformed Infrared Spectroscopy and X-ray diffraction to observe crystalline phases. Carbon structures were prepared from low-density polyethylene, used as representative compound of plastic solid waste by Chemical Vapor Deposition over 20% Ni/Al catalyst in a tubular furnace. Scanning Electron Microscopy analyses were performed, identifying the carbon nanostructures with size variation (1 μm to 4 μm). For paracetamol (PCM) removal Catalytic Wet Peroxide Oxidation was assessed with 20%Ni:80%Al, 10%Fe:10%Ni:80% and commercial Al2O3 catalysts. The conversion of paracetamol, hydrogen peroxide and Total Organic Carbon (TOC) were monitorized by High-Performance Liquid Chromatography, UV-Vis spectrophotometer and TOC analyzer, respectively. The iron-containing catalyst showed the highest catalytic activity in the CWPO of PCM satisfactory conversions (complete removal of PCM after 4 h of reaction time under the following operating conditions: Ccat = 2.5 g/L, CPCM,0 = 100 mg/L, pH0 = 3.5, and CH2O2 = 472.4 mg/L).