Browsing by Author "Cisneros Ramos, Juan Fernando"

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Adsorption of estradiol by natural clays and Daphnia magna as biological filter in an aqueous mixture with emerging contaminants
(2021) Cipriani Ávila, Eva Isabel; Capparelli, Mariana V.; Jara Negrete, Eliza Nuit; Alvarado Martínez, Andrés Omar; Cisneros Ramos, Juan Fernando; Tripaldi, Piercosimo; Perez Gonzalez, Bolivar Andres; Pinos Vélez, Verónica Patricia
Among emerging pollutants, endocrine disruptors such as estradiol are of most concern. Conventional water treatment technologies are not capable of removing this compound from water. This study aims to assess a method that combines physicochemical and biological strategies to eliminate estradiol even when there are other compounds present in the water matrix. Na-montmorillonite, Ca-montmorillonite and zeolite were used to remove estradiol in a medium with sulfamethoxazole, triclosan, and nicotine using a Plackett–Burman experimental design; each treatment was followed by biological filtration with Daphnia magna. Results showed between 40 to 92% estradiol adsorption in clays; no other compounds present in the mixture were adsorbed. The most significant factors for estradiol adsorption were the presence of nicotine and triclosan which favored the adsorption, the use of Ca-montmorillonite, Zeolite, and time did not favor the adsorption of estradiol. After the physicochemical treatment, Daphnia magna was able to remove between 0–93% of the remaining estradiol. The combination of adsorption and biological filtration in optimal conditions allowed the removal of 98% of the initial estradiol concentration.
Assessment of decentralized wastewater treatment systems in the rural area of Cuenca, Ecuador
(IWA PUBLISHING, 2017-03-01) Alvarado Martínez, Andrés Omar; Cisneros Ramos, Juan Fernando; Idrovo Murillo, Diego Benjamin; Sanchez Merchan, Esteban Andrés
The rapid urbanization of Cuenca, Ecuador, since about 1990 has led to efforts to build and operate decentralized domestic wastewater treatment systems in periurban and rural areas. The treatment efficiency of some of these is falling, however, and others are no longer working. ETAPA, the municipal institution in charge of water supply and sanitation, is evaluating them fully to identify common operating and maintenance difficulties, as well as deficiencies in design and/or construction. This paper presents an evaluation of the physical infrastructure and characterization of the treatment processes performed historically. The objective is to overcome the technical deficiencies and adopt a long-term, sustainable O&M plan.
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.
Caracterización de agua potable proveniente de tres principales plantas potabilizadoras de la ciudad de Cuenca, en sus características fisicoquímicas, contenido de aluminio, cloro residual y cafeína, en periodo seco y húmedo
(Universidad de Cuenca, 2023-11-17) Carrión Aguilar, Viviana Paulette; Chaca Jimbo, Ismael Arnaldo; Pinos Vélez, Verónica Patricia; Cisneros Ramos, Juan Fernando
The physicochemical characteristics, aluminum content, free residual chlorine, and caffeine content of drinking water from three water treatment plants in the city of Cuenca were studied during May and July 2023, which correspond severally to rainy and summery seasons. The potable water treatment plants studied were: Tixán, which is supplied by the Machángara River; Cebollar, supplied by the Tomebamba river; and Sustag, whose source of supply is the Yanuncay River. Seven sampling points were set down per water treatment plant, two inside the plant (intake and outlet), and five random points, that were taken from official distribution Etapa EP’s diagram. A total of 210 samples were collected. They were examined to free residual chlorine, aluminum, pH, color, turbidity, and conductivity. In addition, the samples were solid-phase extracted and analyzed by HPLC-UV for caffeine content. The results indicated that residual free chlorine, aluminum content, pH, color, and turbidity did not exceed the maximum permissible limits established by the corresponding standards, TULSMA and NTE INEN-1108. None of the samples indicated caffeine presence. In general, there were no significant differences between seasons or potable water treatment plants. In conclusion, it was proved that studied potable water achieves to requirements set on local standards.
Caracterización de la erodibilidad de suelos en las zonas de alta producción de sedimentos en la cuenca media del Río Paute mediante el análisis de estabilidad de agregados
(2008) Cisneros Ramos, Juan Fernando; García V., Ana Isabel; Cisneros Espinoza, Felipe Eduardo
CFD study to determine the optimal configuration of aerators in a full-scale waste stabilization pond
(2013-09-01) Alvarado Martínez, Andrés Omar; Cisneros Ramos, Juan Fernando
Aerated lagoons (ALs) are important variants of the pond wastewater treatment technology that have not received much attention in the literature. The hydraulic behaviour of ALs and especially the Facultative aerated lagoons (FALs) is very complex since the aeration in these systems is designed for oxygen transfer but not necessarily to create complete mixing. In this work, the energy expenditure of the aerators was studied by means of a scenario analysis. 3D CFD models (one phase and multiphase) of a 3ha FAL in a waste stabilization pond system in Cuenca (Ecuador) were built for different configurations of aerators. The thrust produced by the aerators was modelled by an external momentum source applied as velocity vectors into the pond fluid. The predictions of a single phase model were in satisfactory agreement with experimental results. Subsequently, a scenario analysis assessing several aeration schemes with different numbers of aerators in operation were tested with respect to velocity profiles and residence time distribution (RTD) curves. This analysis showed that the aeration scheme with all 10 aerators switched on produces a similar hydraulic behaviour compared to using only 6 or 8 aerators. The current operational schemes comprise of switching off some aerators during the peak hours of the day and operating all 10 aerators during night. This current practice could be economically replaced by continuously operating 4 or 6 aerators without significantly affecting the overall mixing. Furthermore, a continuous mixing regime minimises the sediment oxygen demand enhancing the oxygen levels in the pond. © 2013 Elsevier Ltd.
Comparación de las eficiencias de recuperación de lípidos de las microalgas Chlorella y Scenedesmus obtenidas con diferentes disolventes
(2018) Pauta Calle, Gladys Guillermina; León Tamariz, Fabián; Cisneros Ramos, Juan Fernando; Pinos Vélez, Verónica Patricia; Alvarado Martínez, Andrés Omar
The lipids of microalgae are the source for obtaining third-generation biofuels so that fossil fuels canbe replaced. The objectives of this study were to determine the composition of the lipids of Chlorella and Scenedesmus microalgae using the gravimetric method; Determine the efficiency of different solvents for the extraction of lipids with the Soxhlet method and compare the lipid recovery productivities of Chlorella microalgae with thermal and physical pretreatments. The highest amount of lipids, 20.37% per dry sample, the microalga, the chlorella, the solvent mixture, the chloroform:methanol in a 1:2 ratio. The increase in the amount of lipids generated with the use of pretreatments no justifies its use for which it is recommended that no pretreatment be applied. The results allow to establish a baseline in the use of microalgae cultivable in the Ecuadorian mountain to obtain lipids for biofuels
Development of an automated tracer testing system for UASB laboratory-scale reactors
(2021) Cisneros Ramos, Juan Fernando; Nopens, Ingmar; Pinos Vélez, Verónica Patricia; Peláez Samaniego, Manuel Raúl; Alvarado Martínez, Andrés Omar
Residence time distribution (RTD) curves play an essential role in the hydraulic characterization of reactors. Current approaches for obtaining RTD curves in laboratory-scale reactors are time-consuming and subject to large errors. Thus, automated systems to obtain RTD curves in laboratory-scale reactors are of great interest for reducing experimental errors due to human interaction, minimizing experimentation costs, and continuously obtaining experimental data. An automated system for obtaining RTD curves in laboratory-scale reactors was designed, built, and tested in this work. During the tests conducted in a cylindrical upflow anaerobic sludge blanket (UASB) reactor, the system worked properly using the stimulus–response pulse technique with sodium chloride as a tracer. Four main factors were found to affect the representativeness of the RTD curves: flow stabilization time, test water conductivity, temperature, and surface tension. A discussion on these factors and the corresponding solutions is presented. The RTD curves of the UASB reactor are left-skewed with a typical tank reactor’s flow shape with channeling and dead zones. A transitory flow behavior was evidenced in the reactor, which indicates the influence of internal turbulent flow structures. The system proposed herein is expected to help study the hydraulics of reactors using laboratory-scale models more efficiently
Diseño de un programa de recolección de medicamentos no utilizados y caducados de los hogares en la zona urbana de Cuenca
(2016) Cobos Cobos, Fabiola Estefanía; Cisneros Ramos, Juan Fernando
Unused or outdated medicines can cause negative effects on public health and the environment. For instance, if they are stored in the household, they are available for self-medication, and if they are disposed within the regular waste, they could contaminate water sources. Therefore, the aim of this research is to design a program of recollection of unused or outdated medicines from the homes of the urban region of Cuenca-Ecuador. First, an academic review of seven programs of recollection that are currently working in different countries and their details are in the public domain was conducted. Then, a survey of twenty-one questions (11, “levels of acceptance”; 10, “preferences”) was designed and applied to a sample of (n=358) individuals selected by purposive sampling in the Gil Ramírez Dávalos area. Lastly, medicines collected via a pilot study of four weeks in the ETAPA-EP multiservice center of Tarqui were characterized. The results of the survey show that 95,3% of the individuals are willing to participate in a recollection program. The reviewed information about the programs and about the preferences was used to design the pilot study which gathered 2481 g of pharmaceutical waste. Among this waste, 85 different drugs were found and 27 have ecotoxicological effects registered on Wikipharma. The results show the need and the importance of the management of pharmaceutical waste generated in the households. Finally, the optimal characteristics for a program of this sort that will encourage the proper treatment of this type of waste are described.
Estimación del potencial energético proveniente de biomasa agroforestal en la provincia de Los Ríos-Ecuador
(2015) Quizhpe Parra, Carlos Hernán; Cisneros Ramos, Juan Fernando
This study aims to estimate the potential of energy from agricultural and forestry biomass in the coverage area of the Pacalori megaproject, project developed by the Secretaría Nacional del Agua (SENAGUA) of Ecuador and Proyecto para el Manejo del Agua y del Suelo (PROMAS) of the University of Cuenca, has 190,000 hectares in the province of Los Rios, in addition Balzar canton of Guayas province, Ecuador. This estimate takes into account only the fraction of the biomass located on ground level, AGB. LiDAR technology was used in this estimate. By way of comparison AGB estimation was performed using vegetation indices (IV), these were the Normalized Differential Vegetation Index (NDVI) and Leaf Area Index (LAI). From LiDAR point cloud belonging to different study area Digital Elevation Models (DEM) according to the present in the same coverages they were generated. The range of height values present in these DEM was used for the weighted average height of hedges. Using empirical equations based on these heights the average values obtained 859,174.2 Mg on average, taking into account the usable biomass reaches 54%. Finally the thermal analysis of samples taken in the field was done. Thus the usable energy potential of the study area TJ 11'907,591.25 obtaining an average energy was estimated.
Estrategias para minimizar la producción de residuos peligrosos y maximizar la recuperación de materiales: un análisis del flujo de materiales en Continental Tire Andina S.A.
(Universidad de Cuenca, 2025-09-02) Espinoza Murillo, Andrea Nayeli; Vásquez Ochoa, Kenny Leonardo; Cisneros Ramos, Juan Fernando
The objective of this study is to minimize the production of hazardous waste and maximize the recovery of materials in the tire industry, Continental Tire Andina S.A., through a material flow analysis of the productive and non-productive processes that generate hazardous waste. A qualitative material flow analysis of the entire plant process and a quantitative material flow analysis was carried out over a period of one month, with the areas that produce the greatest amount of hazardous waste, including the productive process of mixing and relating it to the non-productive processes: laboratory, cleaning, maintenance and operation, using the STAN software.The areas and causes of hazardous waste generation in the plant were identified and 8 management strategies grouped into three scenarios were established: operational optimization, technical innovation and control of priority waste. Each of the scenarios was evaluated technically, environmentally and economically, with the best alternative being scenario 3, which includes management improvement strategies, process changes and material substitution, resulting in a reduction of 14 407,61 kg of hazardous waste and generating savings of US$3 760,3 per month in its treatment. This scenario stands out for the positive environmental impact it generates and the balance between technical and economic aspects.
Hydrodynamic assessment of different UASB reactor’s influent distribution systems to improve granulation
(Universidad de Cuenca, 2022-05-17) Cisneros Ramos, Juan Fernando; Alvarado Martínez, Andrés Omar
Wastewater treatment systems are implemented to remove wastewater pollutants before discharge into receiving water bodies. Wastewater can negatively affect the ecosystem of the receiving water body if proper treatment is not conducted. Despite its importance, small coverage of wastewater treatment systems has been achieved worldwide mainly due to the related high construction and operating costs. According to the Food and Agriculture Organization, about 80% of the world’s wastewater generation is discharged into the environment without any treatment, especially in low-income countries. Anaerobic biological wastewater treatments could be an answer to reduce treatment costs. Anaerobic technologies offer advantages over competing technologies such as reduced land footprint, small reactor volume, reduced excess sludge production, and the ability to recover energy through methane capture. The most widespread anaerobic technology worldwide is the Upflow Anaerobic Sludge Blanket (UASB) reactor. The UASB reactor uses an upward flow to produce granular sludge capable of treating high organic loads. Although there is extensive information on the microbiology of these granules and their efficiency in treating different wastewater qualities, further research is required to better understand the relationship between granule formation and reactor hydrodynamics. Flow hydrodynamics, almost entirely controlled by the reactor's Influent Distribution System (IDS), is key to consider during the UASB reactor’s design since it modules the substrate distribution inside the reactor and the formation of stagnant and short-circuited zones. The IDS role is critical, especially during the reactor's start-up stage when the granular sludge starts to form. This thesis aimed to advance our understanding of the flow hydrodynamics impact on the operation and efficiency of the UASB reactor during its startup stage. The research was divided into two main stages. The first stage was dedicated to physically modeling the reactor using a Froude dynamic similitude scaled reactor and developing an automated tracer testing system. This system allowed us to determine the importance of controlling the test water's conductivity, temperature variation, and surface tension during the tracer tests. The second stage was devoted to numerically modeling the hydrodynamics of the UASB reactor using computational fluid dynamics (CFD) simulations. Initially, the research focused on finding the turbulence closure model that best reproduced the reactor’s hydrodynamics. Thus, CFD simulations were conducted using the realizable k-epsilon model to assess the potential volume of granule generation for IDS configurations commonly used in the literature. The simulations confirmed that the IDS configuration recommended by the design guidelines has a high performance in reducing stagnant and short-circuited zones. This research proposed a novel IDS configuration that generated a granulation volume 22% larger than the recommended IDS configuration, potentially reducing UASB reactor start-up time. The research demonstrates the potential of using physical and numerical techniques as a basis for the model-based design approach to solve problems specific to UASB reactors, an approach that could be extrapolated to other types of reactors.
Hydrodynamic evaluation of five influent distribution systems in a cylindrical UASB reactor using CFD simulations
(2021) Cisneros Ramos, Juan Fernando; Cobos Cobos, Fabiola Estefania; Peláez Samaniego, Manuel Raúl; Nopens, Ingmar; Alvarado Martínez, Andrés Omar
UASB reactors are a promising option for environmentally friendly wastewater treatment due to their reduced carbon footprint and their capacity to treat a variety of wastewater strengths, among other recognized advantages over alternative wastewater treatment systems. The Influent Distribution System (IDS) is a critical structure for generating granules in a UASB reactor since it provides the required flow hydrodynamics for their formation. Thus, the objective of this study was to evaluate and compare the efficiency of five IDS configurations to generate ideal granulation conditions using Computational Fluid Dynamics (CFD) simulations. The IDS configurations were as follows: (C1) single radial inflow, (C2) upward axial inflow, (C3) downward distributed axial inflow, and two novel configurations in the form of (C4) double opposite radial inflow and (C5) downward tangential inflow. The hydrodynamic response of configuration C1 was validated in a physical model with dynamic Froude similitude. The granulation measurement was velocity-based in the reactor reaction zone using steady-state CFD simulations. The novel IDS configuration C4 was the one that resulted in the highest granulation volume, with up to 45.5% of the potential granulation volume of the UASB reactor, in contrast to the IDS C2 that obtained the lowest granulation with only 10.8%. Results confirm that the IDS directly impacts the hydrodynamics of the reactor and that model-based design can be used to ascertain IDS configurations that better promote granulation in UASB reactors
Obtención de densidades aparentes de los componentes de mayor generación dentro de los residuos sólidos municipales en la ciudad de Cuenca
(2015) Pillaga Agualema, Luis Marcelo; Pomaquiza Pomaquiza, Diego Armando; Cisneros Ramos, Juan Fernando
The present project finds to solve one of the most important problems in the characterization of the municipal solid waste (MSW) by the photogrammetry method, the density lack, and, weight units able to apply in the characterization zone. The collection and processing of municipal solid waste is a complex process that requires lots of basic information with which to start the design process. This information is obtained by means of the characterization of the MSW. In the actuality the public cleaning company in Cuenca (Empresa Municipal de Aseo de Cuenca, EMAC- EP), make their characterization in a manual way, where staff separatesthewasteintothepreviouslyselectedcategories. This technique, however, has the potential to cause injury and illness to personnel performing this characterization, because the types of materials that will bepresent as well as their physicalchemical and biological characteristics are ignored. To resist this problem the characterization skill has been developed by photogrammetry. This technique relies on the use of ortho photos in high definition, and requires precise knowledge of unit weights and high densities of materials present in MSW disposed in this city. This technique minimizes the direct contact with the waste to analyze the photographs in the comfort of an office. The information obtained will be presented in a table of apparent densities and / or unit weights. This information will be contrasted with data from the academic literature after a full literature review.
Optimización de rutas de recolección de desechos sólidos domiciliarios mediante uso de herramientas SIG
(2015) Cusco Tenesaca, Jorge Willan; Picón Aguirre, Kristoffer Efraín; Cisneros Ramos, Juan Fernando
This study uses GIS tools use GIS tools to optimize routes for collection of municipal solid waste (MSW) generated in the canton Cuenca, the company responsible for the collection is the EMAC EP. The proposed methodology is based on technical recommendations, GIS tools, information from the existing fleet, the analysis of road networks in the city for the generation of optimized routes.