Examinando por Materia "Palm oil"

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    Adsorption of Cadmium Using Biochars Produced from Agro-Residues
    (American Chemical Society, 2020-01-01) López J.E.; Builes S.; Heredia Salgado M.A.; Tarelho L.A.C.; Arroyave C.; Aristizábal A.; Chavez E.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Bioingeniería GIB (CES – EAFIT)
    Biochars have been shown as promising materials for cadmium remediation. However, the different precursors and the pyrolysis process operating conditions can yield very different surface functional groups, and as a result, different cadmium sorption mechanisms can be observed in biochars. Herein we present the results of cadmium sorption on biochars produced from the pyrolysis of different agro-residues, namely, coffee husk, quinoa straw, and oil palm kernel shell. The adsorption isotherms were used to determine the influence of the biochar's physicochemical characteristics to their sorption behavior. The biochars prepared from quinoa residues showed much higher cadmium uptakes than the other biochars. The concentration of base cations was found to be a critical factor for cadmium sorption. Although the quinoa biochars presented large uptakes, it was found that base cations were supported on the biochars and could be removed by leaching. Results from this study suggest that concentration of base cations on biochars could be used as predictors of the biochar capabilities for the removal of cadmium in aqueous solution. Copyright © 2020 American Chemical Society.
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    Adsorption of Cadmium Using Biochars Produced from Agro-Residues
    (American Chemical Society, 2020-01-01) López J.E.; Builes S.; Heredia Salgado M.A.; Tarelho L.A.C.; Arroyave C.; Aristizábal A.; Chavez E.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Desarrollo y Diseño de Procesos
    Biochars have been shown as promising materials for cadmium remediation. However, the different precursors and the pyrolysis process operating conditions can yield very different surface functional groups, and as a result, different cadmium sorption mechanisms can be observed in biochars. Herein we present the results of cadmium sorption on biochars produced from the pyrolysis of different agro-residues, namely, coffee husk, quinoa straw, and oil palm kernel shell. The adsorption isotherms were used to determine the influence of the biochar's physicochemical characteristics to their sorption behavior. The biochars prepared from quinoa residues showed much higher cadmium uptakes than the other biochars. The concentration of base cations was found to be a critical factor for cadmium sorption. Although the quinoa biochars presented large uptakes, it was found that base cations were supported on the biochars and could be removed by leaching. Results from this study suggest that concentration of base cations on biochars could be used as predictors of the biochar capabilities for the removal of cadmium in aqueous solution. Copyright © 2020 American Chemical Society.
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    Evaluación de la producción de lipasas fúngicas
    (Universidad EAFIT, 2022) Henao Martínez, Mauricio; Olarte Fernández, Ana María; Marín Palacio, Luz Deisy
    Lipases are enzymes that catalyze the hydrolysis and synthesis of esters formed from glycerol and fatty acids. fatty acids, are present in different organisms, however, microbial lipases are of greater interest commercial. These are highly used in industries such as food, paper and pharmaceutical, applicability that is limited by the little evaluation of lipase-producing microorganisms for specific processes, the high production cost and problems associated with the systemic use of enzymes. The rationale for this study is to select from a group of microorganisms of the genera Aspergillus, Penicillium, Fusarium, Trichoderma and Botrytis, a microorganism capable of producing lipid enzymes in a complex medium with a low-cost substrate, as an agro-industrial residue. For this, the radial growth of microorganisms in a solid medium defined with olive oil was evaluated. as the only source of carbon and energy, those with the highest growth were selected to determine the kinetic parameters and lipid activity in a submerged culture with a defined fatty medium, and evaluate the and production of lipid enzymes in a complex medium whose fatty substrate was the residual pulp of the palm oil industry. Among the microorganisms evaluated, it was found that the genera Aspergillus and Penicillium produced lipases. following its growth in defined media with lipids as the only source of carbon and energy, In addition, the lipases produced by Aspergillus flavus have higher activity compared to those produced by Penicillium, however, this microorganism has low lipid activity due to microgram of protein that it had, in the culture in complex medium that was 5.12x10-3 U/mg with respect to the obtained in defined medium of 1.94x10-2 U/mg