Browsing by Author "Vargas Cucurella, Ignacio Tomás"

Now showing 1 - 20 of 37
  • Thumbnail Image
    Item
    A new aerobic chemolithoautotrophic arsenic oxidizing microorganism isolated from a high Andean watershed
    (2018) Anguita, Javiera M.; Rojas, Claudia; Pastén González, Pablo Arturo; Vargas Cucurella, Ignacio Tomás; CEDEUS (Chile)
  • Thumbnail Image
    Item
    A polarized logit model
    (2013) De Grange, Louis; González, Felipe; Vargas Cucurella, Ignacio Tomás; Muñoz Abogabir, Juan Carlos; CEDEUS (Chile)
  • Thumbnail Image
    Item
    Acid Water Neutralization Using Microbial Fuel Cells: An Alternative for Acid Mine Drainage Treatment
    (2016) Leiva, Eduardo; Leiva Aravena, Enzo; Vargas Cucurella, Ignacio Tomás; CEDEUS (Chile)
  • Thumbnail Image
    Item
    Aislamiento y caracterización de un nuevo microorganismo reductor de hierro exoelectrogénico.
    (2017) Zamorano Almonte, Vasty Constanza Nicol; Vargas Cucurella, Ignacio Tomás; Pontificia Universidad Católica de Chile. Escuela de Ingeniería
    La celda de combustible microbiano, en inglés: microbial fuel cell (MFC) es una nueva y emergente bio-tecnología. Las MFCs son dispositivos que generan corriente eléctrica a partir de residuos químicos (orgánicos e inorgánicos), tomando ventaja de la actividad metabólica de microorganismos exoelectrogénicos. En las últimas décadas, un importante esfuerzo se ha invertido en la caracterización de microorganismos exoelectrogénicos modelo. Sin embargo, aún se requieren importantes esfuerzos por aumentar el conocimiento sobre la diversidad de microorganismos que tienen esta capacidad y su potencial utilización en sistemas de tratamiento y remediación ambiental. En este trabajo un microorganismo fue aislado desde el ánodo proveniente de un reactor tipo MFC cuyo inóculo fue inicialmente tomado del enriquecimiento de un sedimento proveniente de una fuente hidrotermal del extremo norte de Chile. Este microorganismo, denominado como V4, fue caracterizado como una bacteria Gram negativo, de forma bacilar, cuya secuencia del gen 16S rARN mostró una cercanía con el género Paenibacillus (99% de identidad, con un 99% de cobertura) perteneciente a la división Firmicutes. Experimentalmente se observó una alta correlación entre la reducción de hierro férrico y el crecimiento bacteriano, utilizando glucosa como donador de electrones, obteniendo una tasa de crecimiento específica de 0,17 h-1. El análisis filogenético basado en el gen 16S rARN mostró que la secuencia del aislado V4 es diferente a todos los Firmicutes descritos anteriormente como exoelectrogénicos, siendo el único Gram negativo de la lista. Pruebas electroquímicas mostraron que el aislado V4 es exoelectrogénico, mostrando una densidad de corriente de 63 ± 42 mAm2, con un peak de oxidación cercano -0,1 V vs Ag/AgCl. La corriente generada por un reactor MFC inoculada con el aislado fue de 15 μA, valor bajo con respecto lo reportado para el estudio de microorganismos modelo, pero que podría explicar el rendimiento de la MFC utilizada como inóculo para aislar este nuevo microorganismo cuya producción de electricidad fue de 45 μA y donde el análisis comunitario por pirosecuenciación reveló ausencia de los géneros comúnmente conocidos como exoelectrogénicos. En consecuencia, el hallazgo de este nuevo microorganismo Firmicute exoelectrogénico no sólo amplía la lista de los microorganismos electroquímicamente activos, sino que podría explicar el rendimiento de la MFC inoculada con el sedimento extraído de un ambiente extremo sin la presencia de microorganismos exoelectrogénicos previamente reportados.
  • Thumbnail Image
    Item
    Arsenic removal mediated by acidic ph neutralization and iron precipitation in microbial fuel cells
    (2018) Leiva, Eduardo; Leiva-Aravena, Enzo; Rodriguez, Carolina; Serrano, Jennyfer; Vargas Cucurella, Ignacio Tomás; CEDEUS (Chile)
  • Thumbnail Image
    Item
    Biocorrosion in drinking water pipes
    (2016) Pizarro Puccio, Gonzalo E.; Vargas Cucurella, Ignacio Tomás; CEDEUS (Chile)
  • No Thumbnail Available
    Item
    Characterization of perchlorate desorption and regeneration of the highly selective ion-exchange resin A530E using 1-butyl-3-methylimidazole chloride, 1-butyl-3-methylimidazole hydroxide, and choline chloride
    (2025) Muñoz Arango, Diana Carolina; Montaño, Diego F.; Veloso Cid, Nicolás Eduardo; Torres-Rojas, Felipe; Canales Muñoz, Roberto; Isaacs Casanova, Mauricio; Hevia, Samuel; Vargas Cucurella, Ignacio Tomás
    Perchlorate is an endocrine disruptor considered an emerging contaminant that poses risks to human health and the environment. Using selective resins is a cost-effective and reliable method for removing perchlorate from drinking water, yet regenerating these resins remains challenging. This study investigates the desorption of perchlorate from a highly selective ion-exchange resin (A530E) using 1-butyl-3-methylimidazole chloride ([Bmim][Cl]), 1-butyl-3-methylimidazole hydroxide ([Bmim][OH]), and choline chloride ([Chl][Cl]). Through three consecutive desorption cycles, [Bmim][OH] exhibited superior performance, achieving up to 23.48 mg·g−1 perchlorate desorption and recovery of nearly 22 % of the resin’s initial adsorption capacity in the second cycle, doubling the yields of the other treatments. Nevertheless, overall regeneration efficiency remained below 50 %, underscoring the need to optimize regenerative strategies. Fourier-transform infrared (FT-IR) spectroscopy indicates specific interactions between the organic salts, perchlorate, and functional groups of the resin. In contrast, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDX) revealed notable changes in surface chemistry and morphology upon desorption. This study demonstrates that the ionic liquids used here can be effective desorption agents for removing perchlorate loaded from resins, thus offering a pathway for applying alternative solutions in water treatment.
  • Thumbnail Image
    Item
    Ciudad y territorio: protección del agua
    (Centro de Desarrollo Urbano Sustentable, 2022) Pastén González, Pablo Arturo; Gironás León, Jorge Alfredo; Bonilla Meléndez, Carlos Alberto; Cortés Arancibia, Sandra; Molinos Senante, María; Precht Rorris, Alejandra; Reyes Paecke, Sonia; Rivera, Javier; Vargas Cucurella, Ignacio Tomás; Vega Contreras, Alejandra Soledad; Vicuña Díaz, Sebastián; CEDEUS (Chile)
    Las ciudades necesitan de recursos críticos como agua, suelo, energía, materiales y alimentos. Tienen una capacidad única de impactar y ser impactadas por las características geomorfológicas y culturales de los territorios donde se emplazan, donde ecosistemas coexisten con actividades humanas como minería, pesca y agricultura. Asegurar la sustentabilidad de la ciudad y del territorio en su conjunto impone un desafío formidable a distintos niveles por la complejidad de las relaciones e interacciones que ocurren.El siguiente documento preparado por investigadores del Centro de Desarrollo Urbano Sustentable y otros colaboradores, entrega antecedentes relevantes respecto del agua como un elemento crítico para la sustentabilidad de las ciudades, con el objetivo de que sirva de un marco para la discusión constitucional sobre protección de recursos críticos para las ciudades y territorios. Además, puede servir de insumo para también ser consultado por la ciudadanía y sus organizaciones.
  • Thumbnail Image
    Item
    Constructed Wetland-Microbial Fuel Cells for Sustainable Greywater Treatment
    (2018) Araneda, Ignacio; Tapia, Natalia F.; Lizama Allende, Katherine; Vargas Cucurella, Ignacio Tomás; CEDEUS (Chile)
  • Thumbnail Image
    Item
    Copper corrosion and biocorrosion events in premise plumbing
    (2017) Vargas Cucurella, Ignacio Tomás; Fischer Montt, Diego A.; Alsina, M.; Pavissich, J.; Pastén González, Pablo Arturo; Pizarro Puccio, Gonzalo E.; CEDEUS (Chile)
  • Thumbnail Image
    Item
    Culture dependent and independent analyses of bacterial communities involved in copper plumbing corrosion
    (2010) Pavissich Bartolozzi, Juan Pablo; Vargas Cucurella, Ignacio Tomás; González, B.; Pastén González, Pablo Arturo; Pizarro Puccio, Gonzalo E.
  • Thumbnail Image
    Item
    Desorption, regeneration and bioreduction of perchlorate with organic salts [Bmim][Cl], [Bmim][OH] and [Chl][Cl] in ion exchange resins
    (2024) Muñoz Arango, Diana Carolina; Vargas Cucurella, Ignacio Tomás; Pontificia Universidad Católica de Chile. Escuela de Ingeniería
    In the world, approximately two billion people live under water stress. In Latin America and the Caribbean, water quality is often poor due to the presence of natural or anthropogenic contaminants. Emerging pollutants (ECs) can negatively affect the environment or human health. In Chile, the soils of the Atacama Desert are the most extensive natural perchlorate reservoirs in the world, directly impacting the composition of drinking water sources in northern Chile. This study addresses the problem of two oxyanions, specifically perchlorate and chlorate, in the drinking water of northern Chilean cities, in the Atacama Desert area. The use of organic salts as an intermediate for perchlorate desorption and regeneration of a highly selective resin for perchlorate was studied. The findings of perchlorate bioreduction in organic salts brines are promising even without adding external carbon sources and electron donors. This study highlights the need to establish systematic monitoring, regulation, and treatment of these ECs in drinking water sources. This study opens the possibility of continuing to investigate the use of organic salts to recove compounds of interest, while extending the useful life of materials such as ion exchange resins.
  • Thumbnail Image
    Item
    Direct laser interference patterning on copper to prevent Variovorax sp. settlement onto metallic surfaces
    (2022) Caro Lara, Luis Alberto; Vargas Cucurella, Ignacio Tomás; Pontificia Universidad Católica de Chile. Escuela de Ingeniería
    El desarrollo de biopelículas perjudiciales en superficies metálicas afecta el rendimiento y vida útil de estas. La micro-texturización con láser aparece como una estrategia novedosa para impedir el crecimiento de biopelículas, bloqueando las etapas iniciales de la adhesión bacteriana y mejorando las características antimicrobianas de los metales. Este trabajo tiene como objetivo estudiar dos efectos de la micro-texturización con láser en cobre sobre la bacteria tolerante a cobre Variovorax sp.: i) la adhesión bacteriana inicial a la superficie, y ii) la inactivación de las bacterias por el efecto de muerte por contacto. En este último objetivo se agregó como control a la bacteria no-tolerante a cobre Escherichia coli. Para llevar a cabo estos objetivos, se produjeron patrones lineales con periodicidades de 4,7, 6,8, 14 y 18 μm mediante texturización laser en cupones de cobre. Las propiedades de la superficie se caracterizaron mediante técnicas microscópicas y espectroscópicas, mientras que la interacción superficie/bacteria se realizó mediante microscopía de epifluorescencia, funcionalización de puntas de microscopía de fuerza atómica y pruebas de muerte por contacto. En cuanto al objetivo i), la periodicidad de 4,7 μm resultó ser el patrón más eficiente para suprimir la adhesión inicial de Variovorax sp. en un 31,1 % comparado con la superficie no texturizada. Además, se observó un asentamiento preferente en los picos por sobre valles para los patrones con periodicidades de 14 y 18 μm, mostrando estos patrones más eventos de adhesión que los diseños más pequeños. En cuanto al objetivo ii) el incremento de Cu(OH)2 resultante del tratamiento con láser y el contacto bacteria-superficie fueron los factores determinantes en el incremento del efecto antimicrobiano del cobre frente a Variovorax sp. y Escherichia coli inactivando el 87% y el 100% de las células tras 2 horas y los primeros 5 minutos del ensayo, respectivamente. Estos hallazgos aportan a la comprensión de la adhesión bacteriana y el efecto de muerte por contacto de las superficies de cobre, contribuyendo así al desarrollo potencial de estrategias inocuas para controlar el crecimiento de biopelículas en materiales hechos con cobre.
  • Thumbnail Image
    Item
    Effect of hazardous bacteria isolated from copper plumbing system on microbiologically influenced corrosion of copper
    (2019) Galarce, Carlos; Pineda Parra, Fabiola Makarena; Fischer Montt, Diego A.; Flores, M.; Vargas Cucurella, Ignacio Tomás; Sancy, Mamié; Pizarro Puccio, Gonzalo E.
  • No Thumbnail Available
    Item
    Effect of hydrochar-doping on the performance of carbon felt as anodic electrode in microbial fuel cells
    (2024) Delgado, Yelitza; Tapia Flores, Natalia Fernanda; Muñoz-Morales, Martín; Ramírez, Álvaro; Llanos, Javier; Vargas Cucurella, Ignacio Tomás; Fernández-Morales, Francisco Jesús
    In this study, the feasibility of using hydrochars as anodic doping materials in microbial fuel cells (MFCs) was investigated. The feedstock used for hydrochar synthesis was metal-polluted plant biomass from an abandoned mining site. The hydrochar obtained was activated by pyrolysis at 500 °C in N2 atmosphere. Under steady state conditions, the current exerted by the MFCs, as well as the cyclic voltammetry and polarization curves, showed that the activated hydrochar-doped anodes exhibited the best performance in terms of power and current density generation, 0.055 mW/cm2 and 0.15 mA/cm2, respectively. These values were approximately 30% higher than those achieved with non-doped or doped with non-activated hydrochar anodes which can be explained by the highly graphitic carbonaceous structures obtained during the hydrochar activation that reduced the internal resistance of the system. These results suggest that the activated hydrochar materials could significantly enhance the electrochemical performance of bioelectrochemical systems. Moreover, this integration will not only enhance the energy generated by MFCs, but also valorize metal polluted plant biomass within the frame of the circular economy.
  • No Thumbnail Available
    Item
    Effect of hydrochar-doping on the performance of carbon felt as anodic electrode in microbial fuel cells
    (Springer Science and Business Media Deutschland GmbH, 2024) Delgado, Yelitza; Tapia Flores, Natalia Fernanda; Muñoz-Morales, Martín; Ramírez, Álvaro; Llanos, Javier; Vargas Cucurella, Ignacio Tomás; Fernández-Morales, Francisco Jesús; CEDEUS (Chile)
    In this study, the feasibility of using hydrochars as anodic doping materials in microbial fuel cells (MFCs) was investigated. The feedstock used for hydrochar synthesis was metal-polluted plant biomass from an abandoned mining site. The hydrochar obtained was activated by pyrolysis at 500 °C in N2 atmosphere. Under steady state conditions, the current exerted by the MFCs, as well as the cyclic voltammetry and polarization curves, showed that the activated hydrochar-doped anodes exhibited the best performance in terms of power and current density generation, 0.055 mW/cm2 and 0.15 mA/cm2, respectively. These values were approximately 30% higher than those achieved with non-doped or doped with non-activated hydrochar anodes which can be explained by the highly graphitic carbonaceous structures obtained during the hydrochar activation that reduced the internal resistance of the system. These results suggest that the activated hydrochar materials could significantly enhance the electrochemical performance of bioelectrochemical systems. Moreover, this integration will not only enhance the energy generated by MFCs, but also valorize metal polluted plant biomass within the frame of the circular economy.
  • Thumbnail Image
    Item
    Electrochemically active microorganisms from an acid mine drainage-affected site promote cathode oxidation in microbial fuel cells
    (2017) Rojas, C.; Vargas Cucurella, Ignacio Tomás; Bruns, M.; Regan, J.; CEDEUS (Chile)
  • Thumbnail Image
    Item
    Enhancing selection for perchlorate-reducing bacteria in presence of competing electron acceptors.
    (2019) Vega Muñoz, Marcela Natalia; Vargas Cucurella, Ignacio Tomás; Nerenberg, Robert; Pontificia Universidad Católica de Chile. Escuela de Ingeniería
    Perchlorate is a ubiquitous water contaminant that inhibits thyroid function. Standards for perchlorate in drinking water range from 2 to 18 μg L-1 in United States and Europe. A major natural source of perchlorate contamination is Chile saltpeter, found in the Atacama Desert in Chile. This dissertation starts by providing a literature review on the unique situation of perchlorate contamination in Chile. The review discusses perchlorate sources, presence in environmental media and in the human population, possible steps to mitigate its health impacts, and opportunities for bioprospecting. Microbial degradation is a promising strategy to remediate perchlorate, as it is reduced to innocuous chloride and oxygen. However, perchlorate is typically found in the μg/L range, and exerts a weak selective pressure for perchlorate-reducing bacteria (PRB). Also, nitrate can inhibit perchlorate reduction, so low nitrate levels are needed. Low nitrate levels can favor sulfatereducing bacteria (SRB). Sulfate reduction has also been related to inhibition of perchlorate reduction. Thus, the overarching goal of this research was to devise strategies to enrich PRB when perchlorate is at low concentrations, together with inhibition of sulfate reduction. The proposed strategy was the addition of the perchlorate analogs chlorate or chlorite. Both are intermediates in the perchlorate reduction pathway, and could have a stronger selective pressure for PRB and also inhibit SRB. The addition of chlorate and chlorite was tested in a hydrogen-based membrane biofilm reactor (H2-MBfR). In this type of reactor, H2 is supplied as electron donor through a hollow fiber membrane and bacteria grow on the surface using nitrate, perchlorate and others as electron acceptors. Chlorate was added for 30 days to a H2-MBfR reducing oxygen, nitrate, perchlorate and sulfate. Before chlorate addition, nitrate and perchlorate were reduced to low levels, but after 17 days sulfate reduction took place, leading to a decrease in perchlorate reduction. When chlorate was added, it increased perchlorate reduction and decreased sulfate reduction. Interestingly, analysis of the microbial community with 16S rRNA high-throughput sequencing suggested that the SRB (Desulfovibrionaceae) relative abundance increased. This was probably due to their role in sulfur cycling, although it cannot be ruled out that they played a role in chlorate reduction. To further understand the effect of chlorate on the microbial community, we tested chlorate addition in a H2-MBfR reducing nitrate, perchlorate and sulfate with similar bulk concentrations as before, but the bulk chlorate concentration was 10 times higher. Although the effect on perchlorate could not be evaluated, chlorate exerted a strong selective pressure for PRB, doubling the abundance of Dechloromonas, a common genus of PRB. As before, our results suggest that chlorate addition inhibited sulfate reduction. To understand the effect of chlorite, we initially determined the potential of chlorite to serve as an indirect electron acceptor and support bacterial growth, as it is dismutated to O2 during perchlorate metabolism. This was successfully proven by first determining O2 production and consumption rates after chlorite additions to PRB and CRB enrichments. Subsequently, the bacterial growth on chlorite was also demonstrated by measurements of the optical density of PRB and CRB cultures. Finally, we evaluated the selective pressure of chlorite in a H2-MBfR reducing nitrate, perchlorate and sulfate. This showed that chlorite had a minor selective pressure. This research provided evidence that adding chlorate and chlorite to a perchlorate H2-MBfR improved perchlorate reduction. Although it should be further studied, the results suggest this strategy could be helpful, particularly in the case of chlorate.
  • No Thumbnail Available
    Item
    Enrichment of electrochemically active microorganisms in a chlorate-pressured environment
    (2025) Cantillo González, Angela Patricia; Torres Rojas, Felipe Ernesto; De La Iglesia Cabezas, Rodrigo Alonso; Vargas Cucurella, Ignacio Tomás
    The study of bioelectrochemical systems (BESs) is gaining importance due to their versatility and wide applications, contributing to a circular bioeconomy. Electrochemically active microorganisms (EAMs) are crucial for catalyzing BES reactions and efficient operation. Applying poised potential in BESs has demonstrated the enrichment of EAMs and improved BES performance. However, in contaminated environments, it remains unclear whether the chemistry of the environment overshadows electrochemical selection. Chlorate is a toxic compound that restricts microbial community composition in BES. The aim of this study was to investigate the dynamic of electrochemical selection of electroactive chlorate-resistant microorganisms in a BES inoculated with sediment from northern Chile. For this purpose, sediment samples were enriched in a three-electrode cell through chronoamperometry with a poised potential of −0.55 V (vs. Ag/AgCl) for 112 days. Electrochemical activity was measured with cyclic voltammetry (CV), and bacterial growth was confirmed using scanning electron microscopy (SEM). Microbial diversity was analyzed via Next Generation Sequencing, and chlorate-resistance EAMs were isolated from the community obtained and characterized. The results showed the enrichment of EAMs that achieved a maximum cathodic current density of 21 μA/cm2. CV confirmed electrochemical activity, and microbial community analysis and scanning electron microscopy showed that attached and planktonic communities changed progressively throughout the experiment. From the communities, three new chlorate-resistant and electroactive isolates were obtained. Thus, this study demonstrated the feasibility of enriching EAMs from chlorate-pressured environments and paved the way for expanding electrochemical selection as a strategy for electro-bioaugmentation and bioremediation.
  • Thumbnail Image
    Item
    Evaluation of microbial electrochemical technologies as a sustainable treatment strategy for nitrogen removal in polluted coastal marine systems
    (2020) Fuente Traverso, María José de la; Vargas Cucurella, Ignacio Tomás; Iglesia Cabezas, Rodrigo Alonso de la; Pontificia Universidad Católica de Chile. Escuela de Ingeniería
    Los ecosistemas marinos costeros del mundo han sido utilizados durante muchos años como receptores de residuos industriales con altas concentraciones de nitrógeno, generando la eutrofización de estos ecosistemas. En este contexto las tecnologías electroquímicas microbianas (MET) han comenzado a ganar atención por su costo y eficiencia en la remoción de nitrógeno y materia orgánica,, utilizando la capacidad metabólica de microorganismos. Sin embargo, todavía tienen limitaciones, como la estrategia de enriquecimiento para comunidades microbianas específicas en los electrodos en condiciones naturales. En esta línea, la aplicación de un sobrepotencial a un electrodo se ha convertido en una técnica de enriquecimiento microbiano sostenible y eficaz. Considerando estos antecedentes, esta tesis estuvo enfocada en dos temas principales. Primero, consolidar la utilización de sobrepotenciales como técnica de enriquecimiento microbiano desde agua de mar natural y lograr enriquecer microorganismos desnitrificantes de manera específica, y (2) desarrollar una MET capaz de remover nitrógeno desde agua de mar natural, utilizando la técnica de enriquecimiento microbiano por sobrepotenciales. Los resultados obtenidos en esta tesis muestran que la aplicación de sobrepotenciales a un electrodo es una técnica efectiva de enriquecimiento de metabolismos microbianos desde un inoculo de agua de mar natural. Específicamente, se demostró que aplicando al electrodo de trabajo -260 mV (vs Ag / AgCl), es posible enriquecer significativamente el establecimiento de microorganismos desnitrificantes. Tomando estos resultados, se logró desarrollar una MET capaz de remover nitrógeno y materia orgánica de manera significativa. En este caso, y diferente a reactores similares reportados en la literatura, el enriquecimiento microbiano en los electrodos se llevó a cabo mediante la aplicación de sobrepotenciales en agua de mar natural, sin la necesidad de uso de medio de cultivo. Específicamente, en el ánodo se observó un enriquecimiento significativo de microorganismos amonio-oxidantes y nitrito-oxidantes, mientras que en el cátodo, se observó un enriquecimiento de microorganismos desnitrificantes y planctomycetes. Finalmente, se logró determinar que el uso de sobrepotenciales podría acelerar el proceso de puesta en marcha de las tecnológicas electroquímicas microbiana y, por ende, ayudar a acelerar su implementación en ambientes reales.