Banca de DEFESA: Clara Vieira Diniz

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : Clara Vieira Diniz
DATA : 25/03/2020
HORA: 14:00
LOCAL: Campus VI
TÍTULO:

Study of the composition of waste from single-dose coffee capsules and catalytic activity investigation in environmental decontamination.

PALAVRAS-CHAVES:

Coffee Capsules; Fenton; nitrogen compounds; sulfur compounds

PÁGINAS: 94
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
SUBÁREA: Química Inorgânica
RESUMO:

With the growth in coffee consumption in the form of single-dose capsules, there is also an increase in the inappropriate disposal of these capsules in landfills and dumps. To find a solution, the reuse of the used single-dose capsules was studied in this work. For this, capsules of the Dolce Gusto® (DG) and Nespresso® (NS) brands were selected and processed by chopping, grinding and heat treatment. The processed capsules were characterized by X-ray diffraction, X-ray fluorescence spectroscopy, scanning electron microscopy, X-ray dispersive energy spectroscopy, thermogravimetry and absorption spectroscopy in the infrared region. From the characterizations, it was observed that DG capsules are composed mainly of polypropylene and small concentrations of Fe and Ti, metals active in Fenton-like processes and photocatalysis, and NS capsules are composed mainly of Al and small concentrations of Fe. To evaluate the catalytic activity of the capsules in the removal of nitrogenous and sulfur compounds from petroleum, the capsules were used in two-phase reactions of the Fenton type using models of nitrogenous contaminants (quinoline) and sulfur (dibenzothiophene) as substrates. The presence of nitrogenous and sulfur substances in fuels is a problem during the refining process and after burning, an environmental problem. The test results showed that the capsules removed up to 32% quinoline by oxidation, and 40% dibenzothiophene by adsorption. Reuse tests on quinoline oxidation showed that heat-treated capsules are more stable than ground and perforated ones. Photocatalytic tests were also carried out in an aqueous medium to remove methylene blue, a contaminant of textile effluents. Both brands removed 99% of the substrate under UV light, while under visible light, the DG capsule removed about 30% and NS 60% of the dye.

MEMBROS DA BANCA:
Presidente - RAQUEL VIEIRA MAMBRINI
Interna - PATRICIA SANTIAGO DE OLIVEIRA PATRICIO
Interno - PATTERSON PATRICIO DE SOUZA
Interna - PRISCILA PEREIRA SILVA CALDEIRA