Person:
Pinos Vélez, Verónica Patricia

Birth Date

1979-02-18

ORCID

0000-0001-8278-5873

Scopus Author ID

57915653200

Afiliación

Universidad de Cuenca, Cuenca, Ecuador
Universidad de Cuenca, Departamento de Biociencias, Cuenca, Ecuador
Universidad de Cuenca, Facultad de Ciencias Químicas, Cuenca, Ecuador
Universidad de Cuenca, Departamento de Recursos Hídricos y Ciencias Ambientales, Cuenca, Ecuador

País

Ecuador

Organizational Units

Organizational Unit

Facultad de Ciencias Químicas

Fundada en 1955 como la Escuela de Química Industrial, la facultad ha sido un pilar fundamental en la formación de profesionales altamente capacitados, comprometidos con el desarrollo de la ciencia, la educación y el bienestar social. La Facultad de Ciencias Químicas pone a consideración su trabajo académico, investigativo y de vinculación con la sociedad, desarrollado a través de la práctica de una docencia de calidad, investigación e innovación en su área de estudio. Desde su oficio de conocimiento se permite contribuir a la sociedad con cuatro carreras: Bioquímica y Farmacia, Ingeniería Química, Ingeniería Ambiental e Ingeniería Industrial. Su carta de presentación en la Academia, la coloca como una dependencia dinámica, donde confluye la solidez de una trayectoria de más de sesenta años. Aquí se trabaja en una continua formación de pregrado y posgrado de la más alta calidad, mediante la mejora continua con la innovación y a la vanguardia de las ciencias químicas.

Job Title

Profesor (T)

Last Name

Pinos Vélez

First Name

Verónica Patricia

Full item page

Search Results

Now showing 1 - 10 of 32

Design and development of a catalytic fixed-bed reactor for gasification of banana biomass in hydrogen production
(2022) Tacuri Sarmiento, Diego Mauricio; Andrade Herrera, Christian Javier; Álvarez Lloret, Edgar Paúl; Abril González, Mónica Fernanda; Salamea Piedra, Teresita Silvana; Pinos Vélez, Verónica Patricia; Jara Cobos, Lourdes Elizabeth; Montero Izquierdo, Iván Andrés
Hydrogen produced from biomass is an alternative energy source to fossil fuels. In this study, hydrogen production by gasification of the banana plant is proposed. A fixed-bed catalytic reactor was designed considering fluidization conditions and a height/diameter ratio of 3/1. Experimentation was carried out under the following conditions: 368 °C, atmospheric pressure, 11.75 g of residual mass of the banana (pseudo-stem), an average particle diameter of 1.84 mm, and superheated water vapor as a gasifying agent. Gasification reactions were performed using a catalyzed and uncatalyzed medium to compare the effectiveness of each case. The catalyst was Ni/Al2O3, synthesized by coprecipitation. The gas mixture produced from the reaction was continuously condensed to form a two-phase liquid–gas system. The synthesis gas was passed through a silica gel filter and analyzed online by gas chromatography. To conclude, the results of this study show production of 178 mg of synthesis gas for every 1 g of biomass and the selectivity of hydrogen to be 51.8 mol% when a Ni 2.5% w/w catalyst was used. The amount of CO2 was halved, and CO was reduced from 3.87% to 0% in molar percentage. Lastly, a simulation of the distribution of temperatures inside the furnace was developed; the modeled behavior is in agreement with experimental observations.
Kinetic Study of Acid Hydrolysis of the Glucose Obtained from Banana Plant
(2023) Abril González, Mónica Fernanda; Vele Salto, Angelica Maria; Pinos Vélez, Verónica Patricia
The biomass of crops in rotation, such as that generated by the banana plant, is an interesting source of lignocellulose due to its composition and availability. This research aimed to compare the amount of glucose obtained from different parts of the banana plant (leaves, rachis, and pseudostem) by hydrolysis with sulfuric acid at 100 °C. This reaction was analyzed to determine the amount of water and reagents consumed versus the glucose obtained. The optimal time and acid concentration were studied between 0–30 min and 3–5% v/v, respectively. The best results were obtained with the pseudostem of 13.02 gL−1 of glucose in a reaction time of 20 min and an acid concentration of 5%. In addition, the kinetic study of hydrolysis was carried out. The adjustment to the Saeman model was R2 0.96, which represents a first-order reaction and kinetic constants K1 = 0.5 and K2 = 0.3 min−1. This study has shown that these residues can be used as raw materials to generate value-added products due to their high glucose content
Microplastics in rivers and coastal waters of the province of Esmeraldas, Ecuador
(2021) Capparelli, Mariana V; Molinero, Jon; Moulatlet, Gabriel M; Barrado, Miren; Prado Alcívar, Santiago; Cabrera, Marcela; Gimiliani, Giovana; Ñacato, Carolina; Pinos Vélez, Verónica Patricia; Cipriani Ávila, Eva Isabel
This study represents the first assessment of microplastic (MP) contamination in the coastal area of the Esmeraldas Province, Ecuador. MPs were quantified in 14 coastal waters in beaches with different urbanization level and in 10 rivers. The most abundant MP types were transparent fibres, brown fragments, grey fragments, transparent fragments, and black fragments, which together represented 84% of the total count. Coastal waters presented significantly higher quantities of MP than rivers. No difference in microplastic abundance was detected between beaches with higher and lower urban occupation, nor between beaches facing North or West. Our results indicate that MP contamination is widespread, and most likely transported from multiple sources. Our results can serve as a baseline for future MP monitoring in the area.
Insights into palladium deactivation during advanced oxidation processes
(2022) Medina Cabello, Francesc; Dafinov, Anton; Pinos Vélez, Verónica Patricia; Osegueda Chicas, Oscar; Crivoi, Dana Georgiana; Llorca, Jordi; García García, Francisco Javier; García Álvarez, Mayra
A key step in creating efficient and long-lasting catalysts is understanding their deactivation mechanism(s). On this basis, the behavior of a series of Pd/corundum materials during several hydrogen adsorption/desorption cycles was studied using temperature-programmed desorption coupled with mass spectrometry and aberration-corrected transmission electron microscopy. The materials, prepared by impregnation and by sputtering, presented uniform well-dispersed Pd nanoparticles. In addition, single atoms and small clusters of Pd were only detected in the materials prepared by impregnation. Upon exposure to hydrogen, the Pd nanoparticles smaller than 2 nm and the single atoms did not present any change, while the larger ones presented a core-shell morphology, where the core was Pd and the shell was PdHx. The results suggest that the long-term activity of the materials prepared by impregnation can be attributed solely to the presence of small clusters and single atoms of Pd.
Production of hydrogen from lignocellulosic biomass: a review of technologies.
(2023) Jara Cobos, Lourdes Elizabeth; Abril González, Mónica Fernanda; Pinos Vélez, Verónica Patricia
Hydrogen is considered one of the most important forms of energy for the future, as it can be generated from renewable sources and reduce CO2 emissions. In this review, the different thermochemical techniques that are currently used for the production of hydrogen from biomass from plantations or crops, as well as those from industrial or agro-industrial processes, were analyzed, such as gasification, liquefaction, and pyrolysis. In addition, the yields obtained and the reactors, reaction conditions, and catalysts used in each process are presented. Furthermore, a brief comparison between the methods is made to identify the pros and cons of current technologies
Human health risk assessment of metals and metalloids in mining areas of the Northeast Andean foothills of the Ecuadorian Amazon
(2022) Moulatlet, Gabriel M.; Capparelli, Mariana V.; Pérez González, Andrés; Galarza Naranjo, Emily Roxana; Pinos Vélez, Verónica Patricia; Cabrera, Marcela; Rico, Andreu
Gold mining (GM) is a major source of metals and metalloids in rivers, causing severe environmental pollution andincreasing the exposure risks to the residents of surrounding areas. Mining in Ecuadorian Amazonia has dramatically in-creased in recent years, but its impacts on Indigenous local populations that make use of rivers are still unknown. The aim ofthis study was to assess the risks to adults and children caused by the exposure to metals and metalloids in freshwaterecosystems contaminated with tailings released by GM activities in 11 sites of the upper Napo River basin, Ecuador. Weselected a carcinogenic and a noncarcinogenic risk assessment method to estimate the hazard index (HI) and total cancerrisk (TCR). The concentration of Ag, Al, As, Cd, Cu, Fe, Mn, Pb, Zn, B, and V in water and sediment samples was considered toassess the risks to human health. The calculated HI was 23–352 times greater than the acceptable limits in all sites for bothchildren and adults. Mn and Fe were the main contributors (75% in water and 99% in sediment) to the total calculated riskbased on the HI. The calculated TCR for children and adults exceeded approximately one to three times the permissiblethreshold in all sites. As and Pb contributed up to 93% of the total calculated risk based on TCR for both children and adults.This study demonstrates that the emission and mobilization of metals and metalloids caused by mining activities increase therisk to human health, to which we recommend further monitoring of freshwater contamination in the area and the im-plementation of preventive health management measures
Biodiesel Production by Transesterification of Recycled Oil Catalyzed with Zinc Oxide Prepared Starting from Used Batteries
(2023) Seminario Calle, Doménica Paulina; Álvarez Lloret, Edgar Paúl; Duque Sarango, Paola Jackeline; Cisneros Ramos, Juan Fernando; Pinos Vélez, Verónica Patricia; Ortega Maldonado, Melissa Isabel; Echeverria Paredes, Paulina Alejandra; Montero Izquierdo, Iván Andrés
The consumption of batteries and cooking oil have been increasing. Most used batteries are disposed of incorrectly, leading to health and environmental problems because of their composition. In a similar form, cooking oil, once used, is often released by the discharge reaching the wastewater, polluting soil, and water, which affects its treatment. In Ecuador, these environmental passives are recollected and stored without further treatment, which is a temporary and unsustainable solution. To address this issue, the circular economy concept has gained increasing attention. In this study, zinc oxide was prepared from discarded batteries using the hydrometallurgical method to use as a catalyst; it achieved 98.49% purity and 56.20% yield and 20.92% of particles presented a particle size of 1–10 nm. Furthermore, the catalyst morphology was investigated in an SEM, which showed that particle size ranged from 155.69 up to 490.15 nm and spherical shapes. Due to its characteristics, the obtained catalyst can be used in the industry instead of the zinc oxide obtained by mining processes. These processes are known to produce heavy contamination in the ecosystems and human health. Additionally, a zinc oxide lifecycle in the environment was analyzed through a material flow analysis (MFA), taking into consideration two paths, one assuming the disposal of used batteries and the other assuming the recycling of zinc. Biodiesel was produced with a heterogeneous catalyst. This took place with a transesterification reaction with used cooking oil, ethanol, and zinc oxide (ZnO) as catalysts. The biodiesel obtained had the following characteristics: 37.55 kJg−1 of heating power, 0.892 gcm−3 of density, 4.189 mm2/s of viscosity, 0.001% of water content, and a 70.91% yield. Furthermore, the energy consumption in biodiesel production was quantified, giving a total of 37.15 kWh. This kind of initiative prevents that waste from becoming environmental pollutants and potential health risks by giving them a second use as a resource. Moreover, turning waste into a valuable product makes the processes self-sustaining and attractive to be implemented.
Ciprofloxacin Removal Using Pillared Clays
(2023) Montero, Carolina; Pinos Vélez, Verónica Patricia; Menendez, Miguel; Jara Cobos, Lourdes Elizabeth; Peñafiel Tenorio, María Eulalia
In this work, Ti-pillared bentonites were evaluated to remove ciprofloxacin (CIP) from the aqueous solution. Pillared sodium bentonite (BSP) and pillared calcium bentonite (BCP) were prepared by means of the sol–gel method using titanium tetraisopropoxide with calcination for 3 h at 500 ◦C. They were characterized using the BET method for N2 adsorption, and subjected to X-ray diffraction and Fourier transform infrared spectroscopy. The results show that the surface area of the pillared bentonites increased after the process, more than the natural ones. Pillared sodium bentonite has a more porous structure, larger surface areas, and higher adsorption capacity than pillared calcium bentonite. The kinetic adsorption of ciprofloxacin (CIP) onto pillared bentonites is well described by the pseudo second-order kinetic model. The BSP isotherm well fitted the Freundlich model, while the BCP isotherm fits the BET model better, suggesting multilayer adsorption. DR model shows mostly physical adsorption for CIP on the two adsorbents. The pH influence study indicated that CIP is adsorbed at pH between 6 and 8, which facilitates the use of BCP and BSP in wastewater treatment, whose pH generally oscillates between these ranges.
Evaluation of the Use of Lime and Nanosilica for the Improvement of Clay Soil Structure and Degradation of Hydrocarbons
(2022) García Villacís, Karina; Cipriani Ávila, Eva Isabel; Ruíz Sánchez, Pablo Sebastián; Hidalgo Lasso, Daniel Francisco; Pinos Vélez, Verónica Patricia
Soil structure is an important key in the bioremediation process; for instance, clay soils tend to have high absorption of pollutants and low rates of bioremediation due to their high plasticity and oxygen restrictions. This work assesses seven different treatments for contaminated clay soil using lime, silica nanoparticles, and both components in combination. After a three-month treatment, the variation of the soil granulometry, pH, porosity, cation exchange capacity (CEC), humidity, organic matter, respirometry, and humic acids were measured in order to evaluate the improvements regarding soil structure. Furthermore, total petroleum hydrocarbon (TPH), polycyclic aromatic hydrocarbons (PAHs) and heavy metals were monitored before and after the treatments. The combined treatment using lime and nanosilica presented the best results, reducing the percentage of clays from 61% to 5% and showing a relationship between improved of soil structure and the reduction of pollutants, with a 35% removal for TPHs being the highest obtained with the seven treatments.
Emerging contaminants in the northeast andean foothills of Amazonia: the case of study of the city of Tena, Napo, Ecuador
(2021) Pérez González, Andrés ; Pinos Vélez, Verónica Patricia; Molinero, Jon; Capparelli, Mariana V.; Cipriani Ávila, Eva Isabel; Jara Negrete, Eliza Nuit; Acosta López, Sofía Paola; Acosta, Byron
This work is a study on the occurrence of emerging pollutants in the northeast Ecuadorian Amazon. Emerging contaminants (ECs)—caffeine, triclosan, estradiol, acetaminophen, nicotine, and ibuprofen—were quantified by gas chromatography–mass spectrometry in rivers and streams of the Amazon basin near the city of Tena, Ecuador. For that, a total of 16 natural water samples were taken in 8 locations. Sampling sites included areas impacted by discharges from inefficient sewage networks in urban areas, wastes from fish farming and non-functional landfill, a stream with few threats, tap water, and treated sewage. Caffeine was found in the 38% of the samples studied while trimethoprim and acetaminophen had an occurrence of 13%. Caffeine was detected at two sites receiving untreated sewage and one site receiving treated sewage with mean concentrations that ranged between 19 and 31.5 μg L−1. Acetaminophen (50.4 μg L−1) and trimethoprim (2 μg L−1) were only detected in the river receiving treated sewage effluent. This is the first assessment of emerging contaminants in the upper Ecuadorian Amazon basin, and our observations highlight the need for better sewage treatment and water quality monitoring in Amazonian cities.