Soil moisture retrieval estimation through the combination of radar (Sentinel-1) and optical images (Sentinel-2) in the basin of the Panama Canal

La humedad del suelo es una variable del ciclo hidrológico que es un factor determinante en el clima, los procesos de escorrentía, evotranspiración, infiltración y atmosféricos que es de suma importancia su estimación de manera precisa, pero por su variabilidad tanto espacial como temporal es muy difícil su determinación. Debido a la gran variabilidad se han buscado métodos para determinar la humedad en el suelo utilizando técnicas de teledetección con satelitales tanto ópticos como de radar. El siguiente estudio tiene como objetivo determinar la humedad del suelo utilizando una combinación de imágenes de radar y ópticas de los satélites Sentinel-1 y Sentinel-2 en el área tropical de la cuenca del canal de Panamá. Se utilizó un método de detección de cambios para determinar la humedad del suelo (HS) basándose en una metodología aplicada anteriormente en Urgell, Cataluña. Las imágenes estudiadas fueron obtenidas en el periodo de octubre de 2017 a febrero de 2019, y el método se basa en determinar la humedad del suelo por el cambio en la señal retrodispersada, este cambio es calculado mediante la diferencia de la señal retrodispersada más seca para un Índice de Vegetación de Diferencia Normalizada (NDVI) dado y las señales retrodispersadas húmedas para ese NDVI en una fecha específica. Con estos métodos de detección de cambios se asume que el cambio de humedad en el suelo se relaciona directamente con el cambio en la señal retrodispersada puesto que por el corto período tiempo parámetros como la rugosidad del terreno o la vegetación no influyen de manera significativa. Con las ecuaciones del método se obtuvieron mapas de humedad del suelo que nos brindan información sobre humedad en cada píxel de la imagen y de forma espacial, está humedad obtenida se relacionó con eventos de precipitación de una estación meteorológica cercana y se observaron que hay relación entre los eventos de lluvia y la humedad estimada. Solamente se relacionó la humedad con la precipitación puesto que no se tienen datos in-situ de HS en la zona de estudio. Se puede concluir que este método puede aplicarse sin datos de campo puesto que se utilizó datos de humedad de imágenes SMOS para desarrollar el método, pero se recomienda validar el método con datos de campo para conocer su confiabilidad.Máster Universitario en Hidrología y Gestión de Recursos Hídrico

Determinación de áreas susceptibles a deslizamientos en el corregimiento de Cerro Punta, provincia de Chiriquí, Panamá

Cerro Punta township is in a geodynamically active area, which combined with anthropic actions makes the threats to landslides recurrent in this area, causing human deaths and economic losses. Based on this problem, a study of susceptible areas to landslides was conducted using the landslide susceptibility index (LSI) method and its further validation. The LSI method is a bivariate statistical model that uses as input data an inventory of historical landslides and parameters, which determine occurrence of landslides. An inventory of 68 georeferenced landslides was used; from this data, a landslide vulnerability map was developed in the study area. A total of 30 of the 68 landslides were used to apply the statistical model and the remaining 38 were used to validate the model, (23 of the 38 landslides data used for validation occurred during the passage of Hurricane ETA). With the statistical model, 9 parameter maps were developed using the software ArcGIS to determine the level of influence of each parameter in the occurrence; the results show that the proximity of streets parameter was the most influential. The ArcGIS weighted overlay tool was used to develop the susceptibility map, of which it generated 5 levels of susceptibility. Finally, the results of the validation show that the map was able to predict 89.4% of the landslides;which provides relevant information for decision-making in landslide risk management, for urban planning and future research in the study area.El corregimiento de Cerro Punta se encuentra en una zona geodinámicamente activa, tanto internamente como externamente. Esto, combinado con las acciones antrópicas, hace que las amenazas a deslizamientos de tierra sean recurrentes en esta zona, causando pérdidas de vidas humanas y económicas. Tomando en cuenta esta problemática, se realizó un estudio de áreas susceptibles a deslizamientos aplicando el método de índice de susceptibilidad a deslizamientos (LSI), con su respectiva validación. El método de LSI es un modelo estadístico bivariado que utiliza como datos de entrada un inventario de deslizamientos históricos y una serie de parámetros que condicionan la ocurrencia de deslizamientos de tierra.  El estudio contó con un inventario de 68 deslizamientos georreferenciados, con los cuales se desarrolló y validó un mapa de susceptibilidad a deslizamientos en la zona de estudio. Del inventario total, 30 deslizamientos fueron utilizados para aplicar el modelo estadístico y 38 para validarlo (23 de estos 38 ocurrieron durante el paso del huracán Eta). Para el modelo estadístico se analizaron 9 mapas de parámetros elaborados en ArcGIS, a fin de conocer el nivel de influencia de cada parámetro, resultando la proximidad a carreteras como el parámetro más influyente. Posteriormente, se utilizó la herramienta de superposición ponderada de ArcGIS para realizar el mapa de susceptibilidad, generando 5 niveles de susceptibilidad. La validación del mapa arrojó un 89.4% de predicción, lo que aporta información relevante para la toma de decisiones en gestión de riesgos, planificación urbana en el área de estudios e investigaciones futura

Evaluación de un filtro biológico de flujo ascendente anóxico a escala de laboratorio para remoción de nitrato

El filtro biológico fue diseñado para trabajar en un ambiente anóxico en donde la masa bacteriana procedente de la materia orgánica dentro del filtro, descompone el nitrato para obtener el nitrógeno y la energía requerida para su desarrollo. Los químicos usados fueron: la fuente de nitrato (140 mg/L de nitrato de potasio), control de oxígeno (250 ml de bisulfato de sodio) y control del potencial de hidrógeno (150 mL de difosfato de potasio). El agua mediante un flujo ascendente alimenta a tres fltros con un volumen de 8 litros c/u, en donde el primer filtro contiene un promedio de 450 tusas de maíz de la especie A, el segundo filtro contiene aproximadamente 600 tusas de maíz de la especie B y el tercer filtro contiene tusas trituradas proveniente de la especie A, las tusas actúan como donantes de electrones y fuente de carbono orgánico para los microorganismos anóxicos. La Evaluación del Sistema consiste en determinar la eficiencia de remoción a través de los parámetros de DQO, DBO, sólidos totales, sólidos volátiles y fjos, sólidos suspendidos y disueltos, temperatura, pH, turbiedad, oxígeno disuelto, análisis microbiológico (tinción de Gram, Coliformes totales y fecales, observación microscópica), nitrato, conductividad y aforos

Spatial, temporal, and demographic patterns in prevalence of chewing tobacco use in 204 countries and territories, 1990-2019 : a systematic analysis from the Global Burden of Disease Study 2019

Interpretation Chewing tobacco remains a substantial public health problem in several regions of the world, and predominantly in south Asia. We found little change in the prevalence of chewing tobacco use between 1990 and 2019, and that control efforts have had much larger effects on the prevalence of smoking tobacco use than on chewing tobacco use in some countries. Mitigating the health effects of chewing tobacco requires stronger regulations and policies that specifically target use of chewing tobacco, especially in countries with high prevalence. Findings In 2019, 273 center dot 9 million (95% uncertainty interval 258 center dot 5 to 290 center dot 9) people aged 15 years and older used chewing tobacco, and the global age-standardised prevalence of chewing tobacco use was 4 center dot 72% (4 center dot 46 to 5 center dot 01). 228 center dot 2 million (213 center dot 6 to 244 center dot 7; 83 center dot 29% [82 center dot 15 to 84 center dot 42]) chewing tobacco users lived in the south Asia region. Prevalence among young people aged 15-19 years was over 10% in seven locations in 2019. Although global agestandardised prevalence of smoking tobacco use decreased significantly between 1990 and 2019 (annualised rate of change: -1 center dot 21% [-1 center dot 26 to -1 center dot 16]), similar progress was not observed for chewing tobacco (0 center dot 46% [0 center dot 13 to 0 center dot 79]). Among the 12 highest prevalence countries (Bangladesh, Bhutan, Cambodia, India, Madagascar, Marshall Islands, Myanmar, Nepal, Pakistan, Palau, Sri Lanka, and Yemen), only Yemen had a significant decrease in the prevalence of chewing tobacco use, which was among males between 1990 and 2019 (-0 center dot 94% [-1 center dot 72 to -0 center dot 14]), compared with nine of 12 countries that had significant decreases in the prevalence of smoking tobacco. Among females, none of these 12 countries had significant decreases in prevalence of chewing tobacco use, whereas seven of 12 countries had a significant decrease in the prevalence of tobacco smoking use for the period. Summary Background Chewing tobacco and other types of smokeless tobacco use have had less attention from the global health community than smoked tobacco use. However, the practice is popular in many parts of the world and has been linked to several adverse health outcomes. Understanding trends in prevalence with age, over time, and by location and sex is important for policy setting and in relation to monitoring and assessing commitment to the WHO Framework Convention on Tobacco Control. Methods We estimated prevalence of chewing tobacco use as part of the Global Burden of Diseases, Injuries, and Risk Factors Study 2019 using a modelling strategy that used information on multiple types of smokeless tobacco products. We generated a time series of prevalence of chewing tobacco use among individuals aged 15 years and older from 1990 to 2019 in 204 countries and territories, including age-sex specific estimates. We also compared these trends to those of smoked tobacco over the same time period. Findings In 2019, 273 & middot;9 million (95% uncertainty interval 258 & middot;5 to 290 & middot;9) people aged 15 years and older used chewing tobacco, and the global age-standardised prevalence of chewing tobacco use was 4 & middot;72% (4 & middot;46 to 5 & middot;01). 228 & middot;2 million (213 & middot;6 to 244 & middot;7; 83 & middot;29% [82 & middot;15 to 84 & middot;42]) chewing tobacco users lived in the south Asia region. Prevalence among young people aged 15-19 years was over 10% in seven locations in 2019. Although global age standardised prevalence of smoking tobacco use decreased significantly between 1990 and 2019 (annualised rate of change: -1 & middot;21% [-1 & middot;26 to -1 & middot;16]), similar progress was not observed for chewing tobacco (0 & middot;46% [0 & middot;13 to 0 & middot;79]). Among the 12 highest prevalence countries (Bangladesh, Bhutan, Cambodia, India, Madagascar, Marshall Islands, Myanmar, Nepal, Pakistan, Palau, Sri Lanka, and Yemen), only Yemen had a significant decrease in the prevalence of chewing tobacco use, which was among males between 1990 and 2019 (-0 & middot;94% [-1 & middot;72 to -0 & middot;14]), compared with nine of 12 countries that had significant decreases in the prevalence of smoking tobacco. Among females, none of these 12 countries had significant decreases in prevalence of chewing tobacco use, whereas seven of 12 countries had a significant decrease in the prevalence of tobacco smoking use for the period. Interpretation Chewing tobacco remains a substantial public health problem in several regions of the world, and predominantly in south Asia. We found little change in the prevalence of chewing tobacco use between 1990 and 2019, and that control efforts have had much larger effects on the prevalence of smoking tobacco use than on chewing tobacco use in some countries. Mitigating the health effects of chewing tobacco requires stronger regulations and policies that specifically target use of chewing tobacco, especially in countries with high prevalence. Copyright (c) 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.Peer reviewe

Global age-sex-specific fertility, mortality, healthy life expectancy (HALE), and population estimates in 204 countries and territories, 1950-2019 : a comprehensive demographic analysis for the Global Burden of Disease Study 2019

Background: Accurate and up-to-date assessment of demographic metrics is crucial for understanding a wide range of social, economic, and public health issues that affect populations worldwide. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 produced updated and comprehensive demographic assessments of the key indicators of fertility, mortality, migration, and population for 204 countries and territories and selected subnational locations from 1950 to 2019. Methods: 8078 country-years of vital registration and sample registration data, 938 surveys, 349 censuses, and 238 other sources were identified and used to estimate age-specific fertility. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate age-specific fertility rates for 5-year age groups between ages 15 and 49 years. With extensions to age groups 10–14 and 50–54 years, the total fertility rate (TFR) was then aggregated using the estimated age-specific fertility between ages 10 and 54 years. 7417 sources were used for under-5 mortality estimation and 7355 for adult mortality. ST-GPR was used to synthesise data sources after correction for known biases. Adult mortality was measured as the probability of death between ages 15 and 60 years based on vital registration, sample registration, and sibling histories, and was also estimated using ST-GPR. HIV-free life tables were then estimated using estimates of under-5 and adult mortality rates using a relational model life table system created for GBD, which closely tracks observed age-specific mortality rates from complete vital registration when available. Independent estimates of HIV-specific mortality generated by an epidemiological analysis of HIV prevalence surveys and antenatal clinic serosurveillance and other sources were incorporated into the estimates in countries with large epidemics. Annual and single-year age estimates of net migration and population for each country and territory were generated using a Bayesian hierarchical cohort component model that analysed estimated age-specific fertility and mortality rates along with 1250 censuses and 747 population registry years. We classified location-years into seven categories on the basis of the natural rate of increase in population (calculated by subtracting the crude death rate from the crude birth rate) and the net migration rate. We computed healthy life expectancy (HALE) using years lived with disability (YLDs) per capita, life tables, and standard demographic methods. Uncertainty was propagated throughout the demographic estimation process, including fertility, mortality, and population, with 1000 draw-level estimates produced for each metric. Findings: The global TFR decreased from 2·72 (95% uncertainty interval [UI] 2·66–2·79) in 2000 to 2·31 (2·17–2·46) in 2019. Global annual livebirths increased from 134·5 million (131·5–137·8) in 2000 to a peak of 139·6 million (133·0–146·9) in 2016. Global livebirths then declined to 135·3 million (127·2–144·1) in 2019. Of the 204 countries and territories included in this study, in 2019, 102 had a TFR lower than 2·1, which is considered a good approximation of replacement-level fertility. All countries in sub-Saharan Africa had TFRs above replacement level in 2019 and accounted for 27·1% (95% UI 26·4–27·8) of global livebirths. Global life expectancy at birth increased from 67·2 years (95% UI 66·8–67·6) in 2000 to 73·5 years (72·8–74·3) in 2019. The total number of deaths increased from 50·7 million (49·5–51·9) in 2000 to 56·5 million (53·7–59·2) in 2019. Under-5 deaths declined from 9·6 million (9·1–10·3) in 2000 to 5·0 million (4·3–6·0) in 2019. Global population increased by 25·7%, from 6·2 billion (6·0–6·3) in 2000 to 7·7 billion (7·5–8·0) in 2019. In 2019, 34 countries had negative natural rates of increase; in 17 of these, the population declined because immigration was not sufficient to counteract the negative rate of decline. Globally, HALE increased from 58·6 years (56·1–60·8) in 2000 to 63·5 years (60·8–66·1) in 2019. HALE increased in 202 of 204 countries and territories between 2000 and 2019

Global burden of 369 diseases and injuries in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

Background: In an era of shifting global agendas and expanded emphasis on non-communicable diseases and injuries along with communicable diseases, sound evidence on trends by cause at the national level is essential. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) provides a systematic scientific assessment of published, publicly available, and contributed data on incidence, prevalence, and mortality for a mutually exclusive and collectively exhaustive list of diseases and injuries. Methods: GBD estimates incidence, prevalence, mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) due to 369 diseases and injuries, for two sexes, and for 204 countries and territories. Input data were extracted from censuses, household surveys, civil registration and vital statistics, disease registries, health service use, air pollution monitors, satellite imaging, disease notifications, and other sources. Cause-specific death rates and cause fractions were calculated using the Cause of Death Ensemble model and spatiotemporal Gaussian process regression. Cause-specific deaths were adjusted to match the total all-cause deaths calculated as part of the GBD population, fertility, and mortality estimates. Deaths were multiplied by standard life expectancy at each age to calculate YLLs. A Bayesian meta-regression modelling tool, DisMod-MR 2.1, was used to ensure consistency between incidence, prevalence, remission, excess mortality, and cause-specific mortality for most causes. Prevalence estimates were multiplied by disability weights for mutually exclusive sequelae of diseases and injuries to calculate YLDs. We considered results in the context of the Socio-demographic Index (SDI), a composite indicator of income per capita, years of schooling, and fertility rate in females younger than 25 years. Uncertainty intervals (UIs) were generated for every metric using the 25th and 975th ordered 1000 draw values of the posterior distribution. Findings: Global health has steadily improved over the past 30 years as measured by age-standardised DALY rates. After taking into account population growth and ageing, the absolute number of DALYs has remained stable. Since 2010, the pace of decline in global age-standardised DALY rates has accelerated in age groups younger than 50 years compared with the 1990–2010 time period, with the greatest annualised rate of decline occurring in the 0–9-year age group. Six infectious diseases were among the top ten causes of DALYs in children younger than 10 years in 2019: lower respiratory infections (ranked second), diarrhoeal diseases (third), malaria (fifth), meningitis (sixth), whooping cough (ninth), and sexually transmitted infections (which, in this age group, is fully accounted for by congenital syphilis; ranked tenth). In adolescents aged 10–24 years, three injury causes were among the top causes of DALYs: road injuries (ranked first), self-harm (third), and interpersonal violence (fifth). Five of the causes that were in the top ten for ages 10–24 years were also in the top ten in the 25–49-year age group: road injuries (ranked first), HIV/AIDS (second), low back pain (fourth), headache disorders (fifth), and depressive disorders (sixth). In 2019, ischaemic heart disease and stroke were the top-ranked causes of DALYs in both the 50–74-year and 75-years-and-older age groups. Since 1990, there has been a marked shift towards a greater proportion of burden due to YLDs from non-communicable diseases and injuries. In 2019, there were 11 countries where non-communicable disease and injury YLDs constituted more than half of all disease burden. Decreases in age-standardised DALY rates have accelerated over the past decade in countries at the lower end of the SDI range, while improvements have started to stagnate or even reverse in countries with higher SDI. Interpretation: As disability becomes an increasingly large component of disease burden and a larger component of health expenditure, greater research and developm nt investment is needed to identify new, more effective intervention strategies. With a rapidly ageing global population, the demands on health services to deal with disabling outcomes, which increase with age, will require policy makers to anticipate these changes. The mix of universal and more geographically specific influences on health reinforces the need for regular reporting on population health in detail and by underlying cause to help decision makers to identify success stories of disease control to emulate, as well as opportunities to improve. Funding: Bill & Melinda Gates Foundation. © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licens

The global burden of cancer attributable to risk factors, 2010-19 : a systematic analysis for the Global Burden of Disease Study 2019

Background Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. Methods The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk-outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. Findings Globally, in 2019, the risk factors included in this analysis accounted for 4.45 million (95% uncertainty interval 4.01-4.94) deaths and 105 million (95.0-116) DALYs for both sexes combined, representing 44.4% (41.3-48.4) of all cancer deaths and 42.0% (39.1-45.6) of all DALYs. There were 2.88 million (2.60-3.18) risk-attributable cancer deaths in males (50.6% [47.8-54.1] of all male cancer deaths) and 1.58 million (1.36-1.84) risk-attributable cancer deaths in females (36.3% [32.5-41.3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20.4% (12.6-28.4) and DALYs by 16.8% (8.8-25.0), with the greatest percentage increase in metabolic risks (34.7% [27.9-42.8] and 33.3% [25.8-42.0]). Interpretation The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.Peer reviewe

Global, regional, and national sex differences in the global burden of tuberculosis by HIV status, 1990–2019: results from the Global Burden of Disease Study 2019

Background Tuberculosis is a major contributor to the global burden of disease, causing more than a million deaths annually. Given an emphasis on equity in access to diagnosis and treatment of tuberculosis in global health targets, evaluations of differences in tuberculosis burden by sex are crucial. We aimed to assess the levels and trends of the global burden of tuberculosis, with an emphasis on investigating differences in sex by HIV status for 204 countries and territories from 1990 to 2019. Methods We used a Bayesian hierarchical Cause of Death Ensemble model (CODEm) platform to analyse 21 505 site-years of vital registration data, 705 site-years of verbal autopsy data, 825 site-years of sample-based vital registration data, and 680 site-years of mortality surveillance data to estimate mortality due to tuberculosis among HIV-negative individuals. We used a population attributable fraction approach to estimate mortality related to HIV and tuberculosis coinfection. A compartmental meta-regression tool (DisMod-MR 2.1) was then used to synthesise all available data sources, including prevalence surveys, annual case notifications, population-based tuberculin surveys, and tuberculosis cause-specific mortality, to produce estimates of incidence, prevalence, and mortality that were internally consistent. We further estimated the fraction of tuberculosis mortality that is attributable to independent effects of risk factors, including smoking, alcohol use, and diabetes, for HIV-negative individuals. For individuals with HIV and tuberculosis coinfection, we assessed mortality attributable to HIV risk factors including unsafe sex, intimate partner violence (only estimated among females), and injection drug use. We present 95% uncertainty intervals for all estimates. Findings Globally, in 2019, among HIV-negative individuals, there were 1.18 million (95% uncertainty interval 1.08-1.29) deaths due to tuberculosis and 8.50 million (7.45-9.73) incident cases of tuberculosis. Among HIV-positive individuals, there were 217 000 (153 000-279 000) deaths due to tuberculosis and 1.15 million (1.01-1.32) incident cases in 2019. More deaths and incident cases occurred in males than in females among HIV-negative individuals globally in 2019, with 342 000 (234 000-425 000) more deaths and 1.01 million (0.82-1.23) more incident cases in males than in females. Among HIV-positive individuals, 6250 (1820-11 400) more deaths and 81 100 (63 300-100 000) more incident cases occurred among females than among males in 2019. Age-standardised mortality rates among HIV-negative males were more than two times greater in 105 countries and age-standardised incidence rates were more than 1.5 times greater in 74 countries than among HIV-negative females in 2019. The fraction of global tuberculosis deaths among HIV-negative individuals attributable to alcohol use, smoking, and diabetes was 4.27 (3.69-5.02), 6.17 (5.48-7.02), and 1.17 (1.07-1.28) times higher, respectively, among males than among females in 2019. Among individuals with HIV and tuberculosis coinfection, the fraction of mortality attributable to injection drug use was 2.23 (2.03-2.44) times greater among males than females, whereas the fraction due to unsafe sex was 1.06 (1.05-1.08) times greater among females than males. Interpretation As countries refine national tuberculosis programmes and strategies to end the tuberculosis epidemic, the excess burden experienced by males is important. Interventions are needed to actively communicate, especially to men, the importance of early diagnosis and treatment. These interventions should occur in parallel with efforts to minimise excess HIV burden among women in the highest HIV burden countries that are contributing to excess HIV and tuberculosis coinfection burden for females. Placing a focus on tuberculosis burden among HIV-negative males and HIV and tuberculosis coinfection among females might help to diminish the overall burden of tuberculosis. This strategy will be crucial in reaching both equity and burden targets outlined by global health milestone

Evaluación de un filtro biológico de flujo ascendente anóxico a escala de laboratorio para remoción de nitrato

El filtro biológico fue diseñado para trabajar en un ambiente anóxico en donde la masa bacteriana procedente de la materia orgánica dentro del filtro, descompone el nitrato para obtener el nitrógeno y la energía requerida para su desarrollo. Los químicos usados fueron: la fuente de nitrato (140 mg/L de nitrato de potasio), control de oxígeno (250 ml de bisulfato de sodio) y control del potencial de hidrógeno (150 mL de difosfato de potasio). El agua mediante un flujo ascendente alimenta a tres fltros con un volumen de 8 litros c/u, en donde el primer filtro contiene un promedio de 450 tusas de maíz de la especie A, el segundo filtro contiene aproximadamente 600 tusas de maíz de la especie B y el tercer filtro contiene tusas trituradas proveniente de la especie A, las tusas actúan como donantes de electrones y fuente de carbono orgánico para los microorganismos anóxicos. La Evaluación del Sistema consiste en determinar la eficiencia de remoción a través de los parámetros de DQO, DBO, sólidos totales, sólidos volátiles y fjos, sólidos suspendidos y disueltos, temperatura, pH, turbiedad, oxígeno disuelto, análisis microbiológico (tinción de Gram, Coliformes totales y fecales, observación microscópica), nitrato, conductividad y aforos

Evaluación de un filtro biológico de flujo ascendente anóxico a escala de laboratorio para remoción de nitrato

El filtro biológico fue diseñado para trabajar en un ambiente anóxico en donde la masa bacteriana procedente de la materia orgánica dentro del filtro, descompone el nitrato para obtener el nitrógeno y la energía requerida para su desarrollo. Los químicos usados fueron: la fuente de nitrato (140 mg/L de nitrato de potasio), control de oxígeno (250 ml de bisulfato de sodio) y control del potencial de hidrógeno (150 mL de difosfato de potasio). El agua mediante un flujo ascendente alimenta a tres fltros con un volumen de 8 litros c/u, en donde el primer filtro contiene un promedio de 450 tusas de maíz de la especie A, el segundo filtro contiene aproximadamente 600 tusas de maíz de la especie B y el tercer filtro contiene tusas trituradas proveniente de la especie A, las tusas actúan como donantes de electrones y fuente de carbono orgánico para los microorganismos anóxicos. La Evaluación del Sistema consiste en determinar la eficiencia de remoción a través de los parámetros de DQO, DBO, sólidos totales, sólidos volátiles y fjos, sólidos suspendidos y disueltos, temperatura, pH, turbiedad, oxígeno disuelto, análisis microbiológico (tinción de Gram, Coliformes totales y fecales, observación microscópica), nitrato, conductividad y aforos