Margarita E. Ramírez Carmona

Universidad Pontificia Bolivariana · Chemical Engineering Program

The exponential growth of electronic waste (e-waste) has raised significant environmental concerns, with projections indicating a surge to 74.7 million metric tons of e-waste generated by 2030. Waste printed circuit boards (WPCBs), constituting approximately 10% of all e-waste, are particularly intriguing due to their high content of valuable metal...

Nanoparticle deposition on various substrates has gained significant attention due to the potential applications of nanoparticles in various fields. This review paper comprehensively analyzes different nanoparticle deposition techniques on ceramic, polymeric, and metallic substrates. The deposition techniques covered include electron gun evaporatio...

Many studies available in the literature focus mainly on the mechanical characterization of fiber, leaving out other physicochemical and thermogravimetric analyses that allow for establishing its potential as an engineering material. This study characterizes fique fiber for its potential use as an engineering material. The fiber’s chemical composit...

This study aims to review and synthesize the rapidly evolving literature on technology transfer from universities, and the concepts and models included in it, from a knowledge-flow approach to find the factors contributing to its performance. This article provides a perspective on recent work, focusing on empirical studies on technology transfer in...

This research presents an experience of post-digital learning of biotechnology in rural areas in Colombia by implementing a massive open online course (MOOC) for biotechnology education called Open Biotec. The objective was to improve Colombian rural development by creating learning communities around five topics: waste management, environmental bi...

Production of bacterial cellulose hydrogel and its evaluation as a proton exchange membrane (PEM) was evaluated. Initially, the bacterial cellulose hydrogel membranes (BCH) was produced by fermentation in a 600 mL bioreactor with a 300 mL medium volume, 10% v/v inoculum with Komagataeibacter hansenii under static conditions, and a temperature of 30...

The fique plant (Furcraea sp.) is a native plant of the Andean region with a great capacity to adapt to different environmental conditions, of which only 4% of the plant is used for developing natural fibers. The comprehensive use of fique and its by-products represents a source of opportunities for the industry and can play an important role in ac...

Production of bacterial cellulose and its evaluation as a proton exchange membrane (PEM) was evaluated. Initially, the bacterial cellulose (BC) was produced by fermentation in a 600 mL bioreactor with a 300 mL medium volume, 10% v/v inoculum with Komagataeibacter hansenii under static conditions, and a temperature of 30°C. The bacteria were cultiva...

The leaching processes for metals using organic substances represent a sustainable approach to recover precious minerals from solid matrices. However, the generation of organometallic species and the lack of thermodynamic diagrams make it difficult to advance the understanding of their behavior and optimize the process. In this work, a thermodynami...

The supply of animal feed is one of the main concerns of producers in the aquaculture industry, including aspects such as the cost of fish flour and its nutritional balance. The aim of this study was the preparation of a pellet-type fish food using powdered Spirulina sp. cultivated as a protein source supplemented with agro-industrial waste, and it...

As natural fibers, low-cost biosorbents have proven to be an effective and clean tool to remove textile dyes from wastewater. In this research, the Reactive Black 5 removal ability of original and enzyme-modified natural fibers were assessed. A fiber extracted from a Colombian fique plant (Furcraea sp.) was employed. The effects of fique fiber prot...

Colombia has a diverse range of marine ecosystems in the coastal and insular areas of the Caribbean Sea and the Pacific Ocean. Seaweed research has focused mainly on the identification and taxonomic distribution of 628 species identified so far, mainly in the Caribbean Sea. Among the most widely cultivated genera of seaweeds in open-sea pilot syste...

Scaling up bioprocesses from the experimental to the pilot or industrial scale involves heuristics and scale relationships that are far from the specific phenomena and are usually not connected to the experimental data. In complex systems, the scaling-up methodology must connect the experimental data with the tools of engineering design. In this wo...

In this work, the production of biologically synthesized silica nanoparticles was proposed to prepare a nanosuspension as a thermal fluid in parabolic solar panels at the laboratory level. Silica nanoparticles were produced from construction sand in two stages. Biosynthesis broth was produced by Aspergillus niger aerated fermentation in a 1 L biore...

In this study, it was evaluated and documented the potential uses of the residual fungal biomass from fermentation. The chemical composition of the biomass was determined by instrumental analysis techniques for its characterization and its possible application. It was found that this biomaterial is generally composed of sugars, proteins, and lipids...

The use of fossil fuels is causing a huge environmental impact due to the emission of air pollutants, greenhouse gases, and other ground and water contaminants; also, these fuels are depleting; the world is facing an energy crisis in the years to come if no preventive actions are done. Renewable energies are arising as promising technologies that w...

This work describes a method for the simultaneous determination of organic acids in fungi fermentation broths. The sample preparation technique and the chromatographic conditions were optimized to enable the monitoring of the fermentation process. The determination of the citric and oxalic acid was done with a high resolution liquid chromatograph a...

It was evaluated the effect of operational conditions in the production of Chlorella sp. after its selection from genus Chlorella sp., Scenedesmus sp., Nannochloris sp., Tetraselmis sp. and Dunaliella salina. Microalgae were inoculated in drinking water with addition of NPK fertilizer (N 24%, P 24%, K 18%), at a concentration of 0.5 g/L, agitation...

This study aims to identify the components of a knowledge management model to support innovation governance in a Colombian cosmetics cluster. The inter-organisational management of knowledge applied to innovation governance, and the perspective of endogenous economic development emphasises the structural specificities of developing countries. In li...

In this work it was carried out the bioremediation of water containing chlorides with native microalgae (MCA) provided by the Centre for study and research in biotechnology (CIBIOT) at Universidad Pontificia Bolivariana. Microalgae presented an adaptation to the water and so the conditions evaluated reaching a production of CO2 in mg L-1 of 53.0, 2...

In this project biogas was purified using separate packed bed adsorption columns using activated carbon, iron filings, kaolin and calcium carbonate. Experiments were performed in 2cm diameter and 9cm length polypropylene columns. The breakthrough curves were constructed with an average biogas flow of 2.2L per day. Samples were taken for almost 28 d...

The objective of this study was to separate the cellulose contained in the fique spall using different ligninolytic fungi fermented broth. The species Pleurotus sp. CBT1, Pleurotus sp. CBT2 and Pycnoporus sanguineous were adapted to a culture medium containing lignin as a carbon source. The degradation of lignin in the culture medium was present be...

In this work, models to correlate the growth of Pseudomonas fluorescens (a gram negative rod shaped bacterium) in the production of medium chain length polyhydroxy-alkanoates (PHA MCL) are analyzed. Sugarcane molasses and glucose were evaluated as carbon source by the cellular growth and production of polyhydroxyalcanoates. It was found that the mo...

Modeling of microbial growth and ammonia consumption at different temperatures was developed in the production of a polyhydroxyalkanoate (PHA) biopolymer in Pseudomona fluorescens in the range of 25–35°C. A logistic model was employed to predict accurately the microbial growth limiting conditions of nitrogen. A new model based in a mixed mathematic...

Este proyecto se inició con la revisión de información secundaria sobre producción agrícola en Antioquia y el procesamiento y análisis de información secundaria para la toma de decisiones en cuanto a cultivos a evaluar, capturada mediante encuesta de campo, trabajo asignado a un técnico para cada subregión de Antioquia para el muestreo. Los datos r...

El fique (Furcraea sp.) es una planta nativa de Colombia, de la cual se extrae sólo un 4% de fibra natural y el otro 96% lo componen el jugo y los bagazos. El jugo de fique contiene aproximadamente 9,71, 28,74 y 13,51 g/L de sacarosa, fructosa y glucosa respectivamente, azúcares que son aprovechados por algunos microorganismos para la producción de...

The invention relates to a system for separating fluids, which uses, as a means for said separation, a matrix comprising a plurality of organic layers interspersed with at least one mineral layer. In preferred modalities, the system can have an initial layer of a removable coarse filter which is biodegradable in order to prevent the saturation of t...

La Universidad Pontificia Bolivariana en Medellín, a partir de una metodología basada en problemas en los cursos de métodos numéricos que integra los conocimientos relacionados con las materias del currículo y de los grupos de investigación propone una modalidad de trabajo que tiene por objeto la formación investigativa a través de un trabajo multi...

Chitosan films reinforced with bacterial cellulose (BC) nanoribbons were studied to understand the influence of acid (acetic and lactic acids) on the reinforcing effect. For both acids, the maximum concentration of the reinforcing constituent was 5 wt% with respect to the dry weight of chitosan. The infrared spectra, mechanical properties, morpholo...

The biotransformation of rice husk ash (RHA) by Fusarium oxysporum to generate silica nanoparticles was carried out using two different commercial growth media: malt-glucose (MG) and malt-glucose-yeast-peptone (MGYP). Biomass production, substrate consumption, organic acids production, and solubilized silica were measured during RHA biotransformati...

Se estudió el efecto de un medio ácido en la síntesis de Polimetilmetacrilato de Glicerol (GXPMMA) utilizando Metilmetacrilato (MMA) y Glicerol como sustancias de partida. Se evaluaron condiciones operacionales del sistema, como temperatura, concentración de ácido y tiempo de reacción a través de un diseño factorial 23. Las muestras obtenidas fuero...

In this investigation, a treatment of expanded polystyrene waste using green solvents is proposed. Agitation and the percentage of green solvent-polystyrene mixture were evaluated at the beginning, obtaining different solutions which were qualitatively analyzed by infrared spectroscopy. Spectra obtained showed the characteristic bands of the functi...

In this investigation, a treatment of expanded polystyrene waste using green solvents is proposed. Agitation and the percentage of green solvent-polystyrene mixture were evaluated at the beginning, obtaining different solutions which were qualitatively analyzed by infrared spectroscopy. Spectra obtained showed the characteristic bands of the functi...

RESUMEN El fique (Furcraea sp.) es una planta nativa de Colombia, de la cual se extrae sólo un 4% de fibra natural y el otro 96% lo componen el jugo y los bagazos. El jugo de fique contiene aproximadamente 9,71, 28,74 y 13,51 g/L de sacarosa, fructosa y glucosa respectivamente, azúcares que son aprovechados por algunos microorganismos para la produ...

The invention relates to a system for separating fluids, which uses, as a means for said separation, a matrix comprising a plurality of organic layers interspersed with at least one mineral layer. In preferred modalities, the system can have an initial layer of a removable coarse filter which is biodegradable in order to prevent the saturation of t...

El fique (Furcraea sp.) es una planta nativa de Colombia, de la cual se extrae sólo un 4% de fibra natural y el otro 96% lo componen el jugo y los bagazos. El jugo de fique contiene aproximadamente 9,71, 28,74 y 13,51 g/L de sacarosa, fructosa y glucosa respectivamente, azúcares que son aprovechados por algunos microorganismos para la producción de...

The graphical representation of global stability for a system, or Pourbaix diagram, was constructed to perform a thermodynamic study of iron removal from kaolin using oxalic acid as an oxidant. To do this the free energies of formation of the oxalate complex of the system were calculated, and it was found that the more stable specie is Fe(C2O4), wi...

La producción de proteína microalgal ha representado desde principios del siglo XX una opción biotecnológica de discutida viabilidad en el manejo y aprovechamiento de desechos orgánicos de origen agrícola, constituyendo una alternativa recurrente de convertir estas fuentes de contaminación en materiales útiles desde un punto de vista económico, nut...

Extracellular synthesis of silica particles was carried out by Fusarium oxysporum mycelia using rice husk ash (RHA) as raw material. RHA before and after bioprocessing was analyzed by SEM and specific surface area. Dissolved silica was quantified using colorimetry. Incubation of rice husk ash with F. Oxysporum at 28°C and pH 6.8 indicated that 80%...

This research was conducted on biosorption of Cr(III), Cu(II) and Zn(II) from industrial effluents using Saccharomyces cerevisiae yeast, residual brewing bioadsorbent, in continuous system. The experiments were carrier in PVC column 4.3 cm diameter and 140 cm length in continuous. The pH values for real solutions contained Cr(III), Cu(II) and Zn(II...

Saccharomyces cerevisiae yeast was immobilized on residual pumice for trivalent and hexavalent chromium solution adsorption inside a PVC column of 4.3 cm diameter, 140 cm length by using a novel redistribution system. Metallic solutions were fed through the packed bed column in order to establish breakthrough curves, inlet solution conditions were...

The bagasse generated as residue during the process of fiber extraction of the fique or sisal (Furcraea sp.) has been evaluated in raw state, washed and thermally activated for the adsorption of chlorothalonil (CLT). The study was developed at 25 ℃ the effects of contact times, biomass dose and pH were investigated. The bagasse was characterized us...

Poliolefinas como el polipropileno son ampliamente utilizadas en el campo agrícola, en particular para la protección y sostenimiento de plantas. Sin embargo, su masivo consumo viene generando importantes problemas ambientales. En este estudio muestras de polipropileno y sus mezclas con almidón y un biopolìmero como el Mater-Bi, los cuales se pueden...

The annual worldwide production of polymeric materials to 1996 was around 150 million ton, with per capita average consumption of plastics in the developed countries of 80-100 K/year, for example, in China was estimated plastics residue in 16 million ton in 2000, being the fifth country in the world responsible for this residue, after U.S., Japan,...

Polyolefins as polypropylene are used in agricultural applications for plant assistance and protection. However, their massive consumption is causing environmental problems. In this study, polypropylene and polypropylene blends with starch and biodegradable polymers such as Mater-Bi that could be used in this agricultural endeavor, were exposed to...

Un equipo de adsorción para la deshidratación de etanol que comprende:(a) Una torre de adsorción que contiene un lecho(b) Una unidad de calentamiento o regeneración(c) Una estructura rígida de orientación vertical El equipo de la reivindicación 1 caracterizado porque la torre de adsorción (a) tiene una forma cilíndrica y un diámetro y altura en rel...

L-aspartic acid is a non-essential amino acid with applications in the chemical, pharmaceutical and food products. It is produced by chemical synthesis or biological, though the former has disadvantages, most prominently the racemic mixture produced. In this paper we use the native strain of Pseudomonas fluorescens and fumaric acid as a source of c...

Trivalent and hexavalent chromium continuous biosorption was studied using residual brewer Saccharomyces cerevisiae immobilized in volcanic rock. The columns used in the process had a diameter of 4.5 cm and a length of 140 cm, working at an inlet flow rate of 15 mL/min. Breakthrough curves were used to study the yeast biosorption behavior in the pr...

An experimental design technique has been used to investigate the biosorption of chromium from water solutions, simulating typical tanning effluents. The United States Environmental Protection Agency (EPA) usually allows solutions containing heavy metals to be discharged if the concentration is less than 5.0 mg/L. The removal of Cr3+ and Cr6+ was s...

Speudoliquen Tillandsia usneoides was used as bioindicator to sorption Pb, Cu, Fe, Zn, Ca and Mg of the Valley of Aburra-Medellin, Colombia. The plants were transplanted from contamination free areas to 20 sample points. This investigation began on January 2003, the samples were collected on March, June, September and December this samples were aci...

The sorption of Cr+3 and Cr+6 on residual Saccharomyces cerevisiae yeas from the beer industry, was studied in relation to pH, metallic concentration in the sorption solution, bioadsorbent concentration and adsorption time. The optimum time of the process was found by determining the bioadsorption kinetic, where it was found that the appropriate ti...

Recently, the transformation of renewable raw materials in bulk chemical has been improved as an object of major research and technological developments around the world. It was estimated that actually 150 millions of tons of polymers are produced from fossil fuel and the production is increasing 4-5% per year. The interest in the use of renewable...

Biodegradation of residual polyurethane by means of Aspergillus niger was evaluated. Respirometric tests were performed using an OXITOP equipment, tests which showed a 98% of consumed oxygen in a 200 hours lapse. Biodegradation was done in an aerated accumulation reactor, at 40% humidity and 25 ºC temperature during 45 days. Spectroscopy IR analysi...