Autor: LILIANA MARIA ALZATE GAVIRIA

EVALUACIÓN DEL DESEMPEÑO E IDENTIFICACIÓN DE EXOELECTRÓGENOS EN DOS TIPOS DE CELDAS DE COMBUSTIBLE MICROBIANAS CON DIFERENTE CONFIGURACIÓN EN EL ÁNODO

LILIANA MARIA ALZATE GAVIRIA (2010)

Se compararon dos celdas de combustible microbianas (CCM) tipo PEM (proton exchance membrane) con diferente configuración en el ánodo, de los cuales se aislaron las respectivas muestras microbianas para identificar el tipo de bacterias presentes mediante la amplificación del gen 16S. La secuenciación de un par de clones evidenció la presencia de alfa y beta proteobacterias entre los exoelectrógenos. Este tipo de bacterias han sido previamente identificados en lodos activados. Los sistemas fueron operados en batch y en intervalos de temperatura mesofílica. En la CCM1 se utilizó grafito de superficie plana y la CCM2 se utilizó grafito granular. El sustrato empleado fue agua residual sintética (ARS), conteniendo hexosa como fuente de carbono, además de emplear un inóculo mixto como biocatalizador; en la cámara del cátodo se empleó un electrodo acuoso saturado de O2. La densidad de poder en la CCM1 fue 6W/m3 con remoción de DQO (demanda química de O2) del 70%, mientras que en la CCM2 se observó un promedio de densidad de poder de ~48W/m3 con 95% de remoción de DQO. Ambos sistemas fueron evaluados durante 120 días, la carga orgánica fue 4,7kg DQO/ m3 por día, y el TRH (tiempo de retención hidráulico) fue 24h.

Artículo

TECNOLOGÍA DE AGUAS RESIDUALES

Characterization of anode and anolyte community growth and the impact of impedance in a microbial fuel cell

LILIANA MARIA ALZATE GAVIRIA DIANA ESTELA SANCHEZ HERRERA DANIELLA ESPERANZA PACHECO CATALAN RUBY ALEJANDRA VALDEZ OJEDA BLONDY BEATRIZ CANTO CANCHE XOCHITL DOMINGUEZ BENETTON JORGE ARTURO DOMINGUEZ MALDONADO (2014)

A laboratory-scale two-chamber microbial fuel cell employing an aerated cathode with no catalyst was inoculated with mixed inoculum and acetate as the carbon source. Electrochemical impedance spectroscopy (EIS) was used to study the behavior of the MFC during initial biofilm (week 1) and maximum power density (week 20). EIS were performed on the anode chamber, biofilm (without anolyte) and anolyte (without biofilm). Nyquist plots of the EIS data were fitted with two equivalent electrical circuits to estimate the contributions of intrinsic resistances to the overall internal MFC impedance at weeks 1 and 20, respectively.

Artículo

MICROBIAL FUEL CELL COMMUNITY GROWTH ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY INGENIERÍA Y TECNOLOGÍA

Lactic Acid Yield Using Different Bacterial Strains, Its Purification, and Polymerization through Ring-Opening Reactions

LILIANA MARIA ALZATE GAVIRIA (2014)

Laboratory-scale anaerobic fermentation was performed to obtain lactic acid from lactose, using five lactic acid bacteria:Lactococcus lactis, Lactobacillus bulgaricus, L. delbrueckii, L. plantarum, andL. delbrueckii lactis. A yield of 0.99 g lactic acid/g lactose was

obtained withL. delbrueckii, from which a final concentration of 80.95 g/L aqueous solution was obtained through microfiltration, nanofiltration, and inverse osmosis membranes. The lactic acid was polymerized by means of ring-opening reactions (ROP) to

obtain poly-DL-lactic acid (PDLLA), with a viscosity average molecular weight (Mv) of 19,264 g/mol.

Artículo

INGENIERÍA Y TECNOLOGÍA

Disminución de la capacidad de intercambio catiónico en una pila de combustible microbiana y su relación con la densidad de potencia

Reduction of cation exchange capacity in a microbial fuel cell and its relation to the power density

JORGE ARTURO DOMINGUEZ MALDONADO ORLANDO GARCIA RODRIGUEZ MANUEL DE JESUS AGUILAR VEGA MASCHA AFRA SMIT LILIANA MARIA ALZATE GAVIRIA (2014)

Se realizó el diseño y construcción de una pila de combustible microbiana (PCM) tipo PEM (Proton Exchange Membrane), constituida por cuatro pares de cámaras con un volumen de 0.5 L cada una, separadas por una membrana de Nafion® 117. La celda fue monitoreada durante 122 días, utilizando agua residual sintética como fuente de carbono. La reducción de la capacidad de intercambio catiónico en la membrana, fue evaluada en dos fases: 1 y 2, la primera a los 43 días y la segunda a los 79 días. Los coeficientes de intercambio catiónico obtenidos en la fase 1 y fase 2 fueron 2.03 _10-3 y 1.25 _10-3 meq g-1 polímero, respectivamente, lo que indica una disminución en las propiedades de intercambio catiónico de la membrana en el tiempo. Los valores máximos de la densidad de potencia obtenidos fueron 325 y 97 mWm-3, respectivamente. La reducción de la potencia obtenida en la fase 2, se atribuyó a la pérdida de capacidad de intercambio catiónico, debido a incrustaciones de hierro y a la capa de depósito orgánico presentes en la membrana.

Artículo

CATION EXCHANGE CAPACITY PROTON EXCHANGE MEMBRANE BIOFOULING MICROBIAL FUEL CELL POWER DENSITY BIOLOGÍA Y QUÍMICA

Vinasses: characterization and treatments

LILIANA MARIA ALZATE GAVIRIA (2011)

The final products of the ethanol industry are alcoholic beverages, industrial ethanol and biofuels. They are produced by the same production process, which includes fermentation and distillation of raw materials which come from plant biomass. At the end of the distillation process a waste effluent is obtained called vinasse or stillage. The direct disposal of stillages on land or in groundwater (rivers, streams or lakes), or even for the direct irrigation of crops, pollutes the environment due to their high organic contents, dissolved solids and many other compounds which are toxic or could be contaminants under certain environmental conditions. This work reviews the characterization of vinasses from different feedstock sources and the main treatments for conditioning the soluble solids of vinasses before their disposal.

Artículo

OTRAS

Saccharification with Phanerochaete chrysosporium and Pleurotus ostreatus enzymatic extracts of pretreated banana waste

XENIA MENA ESPINO LUIS FELIPE BARAHONA PEREZ LILIANA MARIA ALZATE GAVIRIA REFUGIO RODRIGUEZ VAZQUEZ MIGUEL ALONSO TZEC SIMA JORGE ARTURO DOMINGUEZ MALDONADO BLONDY BEATRIZ CANTO CANCHE (2011)

Lignocellulosic biomass has a great potential as raw material for second and third generation biofuels since it is the most abundant carbohydrate on earth and the main component of agricultural waste; however, saccharification of lignocellulosic biomass is crucial for the establishment of a carbohydratebased economy. The use of fungal enzymes is the preferred procedure for lignocellulosic saccharification. Fungi such as basidiomycetes (e.g Phanerochaete chrysosporium) produce cellulolytic/hemicellulolytic and ligninolytic enzymes, which are responsible for lignocellulose degradation. In this study the saccharification of banana flour prepared from pseudostem and green non commercial-grade fruit (1:1), two of the main agro-waste of banana industry was investigated. The material was pretreated by physical and chemical processes including drying and grinding, followed by 3% HCl or 3% NaOH hydrolysis, or a sequential pretreatment with 3% HCl first and then 3% NaOH and heated at 121°C, at 15 Lb/in2 for 15 min. The highest concentration of reducing sugars (RS) was obtained with acid hydrolysis (42.41 gL-1). Crude cellulolytic-ligninolytic enzymatic extracts from Pleurotus ostreatus and P. chrysosporium cultured on banana waste as the only carbon source were prepared and used for the saccharification. Surprisingly, P. chrysosporium crude extract produced a decrease in RS (2.27 gL-1). Although P. ostreatus cellulose activity (17,777.78 UL-1) was almost half compared to P. chrysosporium's (31,296.30 UL-1), the former produced an increment in the release ofRS (63.65 gL-1). In Mexico, banana is one of the main crops and generates large agricultural waste after harvest. According to the results obtained with acid-heat pretreatment followed by saccharification with P. ostreatus enzymatic crude extract, banana agro-waste can be considered as a potential feedstock for RS-based bioproducts like bioethanol.

Artículo

BANANA WASTE LIGNOCELLULOSIC PRETREATMENTS REDUCING SUGARS SACCHARIFICATION BIOLOGÍA Y QUÍMICA

Mathematical model for a continuous hydrogen production system: Stirred fermenter connected to a biocatalyzed electrolysis cell

LILIANA MARIA ALZATE GAVIRIA (2013)

This paper presents a mathematical model applied to a continuous hydrogen production system, composed of a stirred fermenter connected to a biocatalyzed electrolysis cell (BEC).

The model contemplates two differential equation systems which describe the adaptation (start-up) and continuous phases between the fermenter and the BEC. The proposed model

describes the dynamics of hydrogen and volatile fatty acid (VFA) production and substrate consumption (glucose for the stirred fermenter and acetate in the BEC), based on a Tessiertype

bacterial kinetic which simulates the lag phase in the bacteria. A hybrid evolutionary algorithm and least squares method were used to estimate the parameters. Model validation

and simulation were achieved by obtaining the volumes of hydrogen and VFAs produced and the statistical bacterial density via the most probable number (MPN) method.

Artículo

INGENIERÍA Y TECNOLOGÍA

Generación de electricidad a partir de una celda de combustible microbiana tipo PEM

Electricity generation from a PEM microbial fuel cell

LILIANA MARIA ALZATE GAVIRIA MARIA DEL CARMEN FUENTES ALBARRAN ALBERTO ARMANDO ALVAREZ GALLEGOS SEBASTIAN PATHIYAMATTOM JOSEPH (2008)

Se empleó una celda de combustible microbiana (CCM) a escala de laboratorio para la generación de electricidad. La celda consistió de dos cámaras separadas por una membrana de intercambio protónico (PEM). Se utilizaron electrodos de papel carbón y un catolito acuoso burbujeado con aire para proveer O2 disuelto al electrodo. La generación de potencia en la CCM, se debió a la presencia de bacterias como biocatalizadores en la cámara del ánodo. Las bacterias fueron obtenidas de un inóculo mixto anaerobio de tipo entérico, empleando agua residual sintética (ARS) como sustrato. Se determinó la influencia de la temperatura y el pH sobre el rendimiento de la CCM, encontrando que la mayor densidad de potencia fue generada a temperatura mesofílica de 35 ±5°C y pH entre 5 y 6. Empleando resistencias de 600 y 1000W se obtuvieron densidades de 640 y 336mW·m-2, respectivamente. La eficiencia coulómbica obtenida fue de 59,8%. Este tipo de sistemas resultan atractivos para la generación de electricidad y a la vez para la degradación de la fracción orgánica.

Artículo

CELDA DE COMBUSTIBLE MICROBIANA GENERACIÓN ELÉCTRICA INÓCULO MIXTO METABOLISMO FERMENTATIVO INGENIERÍA Y TECNOLOGÍA

Methane production by treating vinasses from hydrous ethanol using a modified UASB reactor

LILIANA MARIA ALZATE GAVIRIA (2012)

Background:A modified laboratory-scale upflow anaerobic sludge blanket (UASB) reactor was used to obtain methane by treating hydrous ethanol vinasse. Vinasses or stillage are waste materials with high organic loads, and a

complex composition resulting from the process of alcohol distillation. They must initially be treated with anaerobic processes due to their high organic loads. Vinasses can be considered multipurpose waste for energy recovery and

once treated they can be used in agriculture without the risk of polluting soil, underground water or crops. In this sense, treatment of vinasse combines the elimination of organic waste with the formation of methane. Biogas is

considered as a promising renewable energy source. The aim of this study was to determine the optimum organic loading rate for operating a modified UASB reactor to treat vinasse generated in the production of hydrous ethanol

from sugar cane molasses. Results:The study showed that chemical oxygen demand (COD) removal efficiency was 69% at an optimum

organic loading rate (OLR) of 17.05 kg COD/m 3

-day, achieving a methane yield of 0.263 m 3

/kg CODaddedand a biogas methane content of 84%. During this stage, effluent characterization presented lower values than the

vinasse, except for potassium, sulfide and ammonia nitrogen. On the other hand, primers used to amplify the 16S-rDNA genes for the domains Archaea and Bacteria showed the presence of microorganisms which favor

methane production at the optimum organic loading rate. Conclusions:The modified UASB reactor proposed in this study provided a successful treatment of the vinasse

obtained from hydrous ethanol production. Methanogen groups (Methanobacteriales and Methanosarcinales) detected by PCR during operational optimum

OLR of the modified UASB reactor, favored methane production. Keywords:Methane yield, Modified UASB reactor, Vinasse from hydrous ethanol, 16S-rDNA genes amplification

Artículo

INGENIERÍA Y TECNOLOGÍA

Role of peroxidases in capsaicinoids degradation in habanero pepper (Capsicum chinense Jacq.) plants grown under water deficit conditions

Characterization of anode and anolyte community growth and the impact of impedance in a microbial fuel cell

LILIANA MARIA ALZATE GAVIRIA (2014)

A laboratory-scale two-chamber microbial fuel cell employing an aerated cathode with no catalyst was inoculated with mixed inoculum and acetate as the carbon source.

Electrochemical impedance spectroscopy (EIS) was used to study the behavior of the MFC during initial biofilm (week 1) and maximum power density (week 20). EIS were performed

on the anode chamber, biofilm (without anolyte) andanolyte (without biofilm). Nyquist plots of the EIS data were fitted with two equivalent electrical circuits to estimate the contributions of intrinsic resistances to the overall internal MFC impedance at weeks 1 and 20,

respectively.

Artículo

INGENIERÍA Y TECNOLOGÍA