Repositorio Institucional Universidad EAFIT ::Examinando por Materia "Biodegradation"

Examinando por Materia "Biodegradation"

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Biodegradation of vegetable residues by polygalacturonase-agar using a trickle-bed bioreactor
(Institution of Chemical Engineers, 2018-09-01) Ramírez-Tapias, Y.A.; Rivero, C.W.; Giraldo-Estrada, C.; Britos, C.N.; Trelles, J.A.; Universidad EAFIT. Departamento de Ciencias; Ciencias Biológicas y Bioprocesos (CIBIOP)
Bacterial pectinases degrade the pectic substances present in plant tissues and particularly, polygalacturonases catalyze the hydrolysis of a-(1,4) glycosidic bonds linking D-galacturonic acid units. In this study, polygalacturonase from Streptomyces halstedii ATCC 10897 was immobilized by the matrix entrapment technique using different thermogels. Bacteriological agar added with magnesium cation produced beads with a more stabilized microstructure for enzyme retention, monitored by oscillatory measurements of storage and loss modulus. Agar concentration and protein content were optimized to maximize protein entrapment, product conversion, and reaction yield. Results showed that the mixture at 10:90% (v/v) of protein (2 mg/mL) and agar (4% w/v) was the best immobilization condition to retain 91% of protein and hydrolyze 38% of pectin to allow the highest reaction yield (9.279 g/g) and increase stability up to 48 h of successive reactions. Agarose bead biocatalysts were used in a trickle-bed column operated with recirculation, and this bioreactor allowed the degradation of pear and cucumber residues by enzymatic liquefaction to enhance sugar content up to 15.33 and 9.35 mg/mL, respectively, and decrease viscosity by 92.3%. The scale-up of this process adds value to vegetable residues such as fructooligosaccharides or fermentable sugars, which become a sustainable source of fuels and chemicals. © 2018 Institution of Chemical Engineers
The Box-Benkhen experimental design for the optimization of the electrocatalytic treatment of wastewaters with high concentrations of phenol and organic matter.
(IWA PUBLISHING, 2009-01-01) GilPavas, Edison; Betancourt, Alejandra; Angulo, Monica; Dobrosz-Gomez, Izabela; Angel Gomez-Garcia, Miguel; GilPavas, Edison; Betancourt, Alejandra; Angulo, Monica; Dobrosz-Gomez, Izabela; Angel Gomez-Garcia, Miguel; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)
In this work, the Box-Benkhen experimental Design (BBD) was applied for the optimization of the parameters of the electrocatalytic degradation of wastewaters resulting from a phenolic resins industry placed in the suburbs of Medellin (Colombia). The direct and the oxidant assisted electro-oxidation experiments were carried out in a laboratory scale batch cell reactor, with monopolar configuration, and electrodes made of graphite (anode) and titanium (cathode). A multifactorial experimental design was proposed, including the following experimental variables: initial phenol concentration, conductivity, and pH. The direct electro-oxidation process allowed to reach ca. 88% of phenol degradation, 38% of mineralization (TOC), 52% of Chemical Oxygen Demand (COD) degradation, and an increase in water biodegradability of 13%. The synergetic effect of the electro-oxidation process and the respective oxidant agent (Fenton reactant, potassium permanganate, or sodium persulfate) let to a significant increase in the rate of the degradation process. At the optimized variables values, it was possible to reach ca. 99% of phenol degradation, 80% of TOC and 88% of COD degradation. A kinetic study was accomplished, which included the identification of the intermediate compounds generated during the oxidation process.
Decolorization and mineralization of Diarylide Yellow 12 (PY12) by photo-Fenton process: the Response Surface Methodology as the optimization tool.
(IWA PUBLISHING, 2012-01-01) GilPavas, Edison; Dobrosz-Gomez, Izabela; Angel Gomez-Garcia, Miguel; GilPavas, Edison; Dobrosz-Gomez, Izabela; Angel Gomez-Garcia, Miguel; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)
The Response Surface Methodology (RSM) was applied as a tool for the optimization of the operational conditions of the photo-degradation of highly concentrated PY12 wastewater, resulting from a textile industry located in the suburbs of Medellin (Colombia). The Box-Behnken experimental Design (BBD) was chosen for the purpose of response optimization. The photo-Fenton process was carried out in a laboratory-scale batch photo-reactor. A multifactorial experimental design was proposed, including the following variables: the initial dyestuff concentration, the H(2)O(2) and the Fe(+2) concentrations, as well as the UV wavelength radiation. The photo-Fenton process performed at the optimized conditions resulted in ca. 100% of dyestuff decolorization, 92% of COD and 82% of TOC degradation. A kinetic study was accomplished, including the identification of some intermediate compounds generated during the oxidation process. The water biodegradability reached a final DBO(5)/DQO = 0.86 value.
Foto-degradación de fenol sobre catalizadores de TiO2 y Mo/TiO2. La metodología de superficie de respuesta como herramienta de optimización
(Centro de Informacion Tecnologica, 2014-01-01) López-Zamora, S.M.; GilPavas, E.; Gómez-García, M.Á.; Dobrosz-Gómez, I.; López-Zamora, S.M.; GilPavas, E.; Gómez-García, M.Á.; Dobrosz-Gómez, I.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)
In this work, the response surface methodology was applied as a tool for the optimization of the operational conditions of phenol photo-degradation over TiO2 and 2% wt Mo/TiO2 catalysts. A multifactorial experimental design was proposed, including the following variables: phenol initial concentration (Ci), catalyst loading (Cat) and pH. The apparent reaction rate constant and the percentage of phenol degradation were chosen as the response variables. When TiO2 was used as catalyst, the following optimal operational conditions were found: Ci=10ppm, Cat=0.7g/L and pH=8 for both UV and visible light. For 2% wt Mo/TiO2 catalyst, the optimal operating conditions strongly depended on the applied radiation source. Thus, under UV radiation: Ci=10 ppm, Cat=0.7 g/L and pH=8 were found as the optimum conditions. Using visible light, and the following optimized conditions, Ci=10 ppm, Cat=0.1 g/L, pH =3.6, the Mo containing catalyst showed to be the most efficient. Under these conditions, the amount of 2% wt. Mo/TiO2 was 7 times lower than that of unsupported TiO2.
Multifactorial optimization of the decolorisation parameters of wastewaters resulting from dyeing flowers.
(IWA PUBLISHING, 2009-01-01) Gil Pavas, Edison; Angel Gomez-Garcia, Miguel; Gil Pavas, Edison; Angel Gomez-Garcia, Miguel; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)
This work deals with the treatment of the wastewaters resulting from the process of dyeing flowers. In some local cases for growing flowers near to Medellin (Colombia), wastewater color was found to be one of the main problems in meeting local effluent standards. Wastewaters were treated by photodegradation process (which includes photocatalysis) to achieve the degradation of dyes mixture and organic matter in the wastewater. A multifactorial experimental design was proposed, including as experimental factors the following variables: pH, and the concentration of both catalyst (TiO(2)) and hydrogen peroxide (H(2)O(2)). According to the obtained results, at the optimized variables values, it is possible to reach a 99% reduction of dyes, a 76.9% of mineralization (TOC) and a final biodegradability of 0.834. Kinetic analysis allows proposing a pseudo first order reaction for the reduction, the mineralization, and the biodegradation processes.
Polímeros biodegradables a partir del almidón de yuca
(Universidad EAFIT, 2005) Ruíz Avilés, Gladys; Palacio González, Guillermo León
Los polímeros tradicionales tienen gran cantidad de aplicaciones especialmente en la industria del empaque, donde se consume un número de toneladas al año, bastante considerable -- Sin embargo, tienen dos desventajas que es necesario tenerlas en cuenta y tratar de resolver los problemas que ocasionan -- La primera es que son fabricados a partir de materias primas obtenidas de recursos no renovables, como el petróleo, que cada día se hace más escaso y por ende más costoso -- La segunda es su persistencia en el medio por tiempos muy largos, lo cual hace que ocupen espacio en los rellenos sanitarios, los cuales ya están produciendo problemas en nuestro país debido a la falta de espacio y dificultad para su ubicación -- En este trabajo se evalúan las condiciones para la obtención de un polímero biodegradable a partir del almidón de yuca, se determinan las condiciones para su procesamiento mediante extrusión y se realiza su caracterización -- El polímero biodegradable se obtiene al preparar diferentes mezclas de almidón modificado de yuca con glicerina como plastificante y agua, las cuales se procesan en un molino abierto, hasta producir bandas con un espesor reducido, que se cortan en tiras y se muelen para obtener escamas pequeñas que luego se alimentan a una extrusora de monohusillo -- Las muestras se secan antes de la extrusión donde las variables a controlar son: el perfil de temperatura, torque, y velocidad de rotación del husillo -- 2 Se evalúan algunas características mecánicas y fisicoquímicas mediante ensayos de Tensión, Calorimetría Diferencial de Barrido (DSC), Análisis Termogravimétrico (TGA), Análisis Infrarrojo por Transformadas de Fourier (FTIR) y Morfología
Removal of water-soluble dye (methylene blue) by yeast Saccharomyces cerevisiae
(Universidad EAFIT, 2020) Acosta Rendon, Melissa; Giraldo Estrada, Catalina; Aristizábal Castrillón, Adriana
Saccharomyces cerevisiae was studied for the removal of methylene blue (MB), a reactive dye, from its aqueous solutions in two different approaches, the first one was determining the removal of MB by biosorption. Factors that affect the biosorption process such as dye concentration, biomass concentration and pH were investigated. The maximum percentage of colour removal, 83.50% in 24 h, was obtained on using cultivated yeast concentration of 0.2 g in 45 mL at 30 º C and pH 3.5, with this result it was concluded that the dried biomass of S. cerevisiae can be considered as a good biosorbent material for reactive dyes as MB. Also, a desorption process was made giving as result a desorption percentage of 65.47% in 120 min with methanol used as a solvent. The second approach was to evaluate the biodegradation of the MB dye with the yeast and, due to the nature of the dye, it is suggested that the yeast only performs biosorption and was unable to take MB as the carbon source for its growth.
Treatment of automotive industry oily wastewater by electrocoagulation: statistical optimization of the operational parameters.
(IWA PUBLISHING, 2009-11-01) GilPavas, Edison; Molina-Tirado, Kevin; Angel Gomez-Garcia, Miguel; GilPavas, Edison; Molina-Tirado, Kevin; Angel Gomez-Garcia, Miguel; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)
An electrocoagulation process was used for the treatment of oily wastewater generated from an automotive industry in Medellin (Colombia). An electrochemical cell consisting of four parallel electrodes (Fe and Al) in bipolar configuration was implemented. A multifactorial experimental design was used for evaluating the influence of several parameters including: type and arrangement of electrodes, pH, and current density. Oil and grease removal was defined as the response variable for the statistical analysis. Additionally, the BOD(5), COD, and TOC were monitored during the treatment process. According to the results, at the optimum parameter values (current density = 4.3 mA/cm(2), distance between electrodes = 1.5 cm, Fe as anode, and pH = 12) it was possible to reach a c.a. 95% oils removal, COD and mineralization of 87.4% and 70.6%, respectively. A final biodegradability (BOD(5)/COD) of 0.54 was reached.

Examinando por Materia "Biodegradation"

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