Dissolved inorganic nitrogen cycling in a river receiving wastewater: the response to changes in wastewater treatment effluent

Nitrogen is an essential element for all life forms, but when in excess in an aquatic ecosystem, it can cause an imbalance in the trophic status. A significant amount of nitrogen is released into the environment by wastewater treatment plants, representing a major point source of reactive nitrogen in urban environments. This nitrogen source presents a potential threat to the ecological integrity of the aquatic ecosystem if poorly managed and monitored. Wastewater discharges can increase the primary production in surface waters, frequently degrading the integrity of the receiving aquatic ecosystem through the addition of high organic matter loads and the associated oxygen consumption during oxidation of the organic matter. The Grand River (south western Ontario) is a river highly impacted by human activities; the watershed is home to approximately 925,000 inhabitants, has approximately 34 water control structures and receives discharge from agricultural fields and 30 wastewater treatment plants. The Central Grand River is particularly influenced by wastewater discharges from five large wastewater treatment plants (WWTPs) in the Region of Waterloo. Due to the impacts of wastewater effluent on the ecological integrity of the Grand River, the Region of Waterloo embarked on a series of upgrades to its two largest WWTPs: the Waterloo and Kitchener plants. This research presents a before-and-after approach used to study and understand the effects of the changes in the operation of the Kitchener wastewater treatment plant. The research documents changes in dissolved inorganic nitrogen dynamics downstream of the Kitchener wastewater treatment plant. Ammonium and nitrate concentrations and nitrogen isotopic composition (δ15N) was monitored in the Central Grand River, with a special focus on the 5700 m reach downstream of the Kitchener wastewater treatment plant effluent over a period of four years (2010 to 2013). The over-riding change in the quality of the wastewater effluent was a decrease in ammonium concentration, resulting in a reduction in the period of oxygen depletion during summer, low flow conditions. After the upgrades, most of the ammonium was oxidized by submerged aeration inside the wastewater treatment plant. However, the concentration of nitrate in the effluent increased as a result of the upgrade to a nitrifying system. The observed rate of ammonium decrease before in the Central Grand River (adjusted by travel time with a flow velocity of 0.3 m/s) varied between 0.7 and 2.47 mgN-NH4+h-1before the upgrades. Together with the changes in concentrations, the observed differences in the isotopic composition of ammonium (δ15NNH4+) and nitrate (δ15NNO3) suggest that ammonia volatilization, assimilation and nitrification occurred in the Central Grand River downstream of the Kitchener wastewater treatment plant. Before upgrades, ammonium concentrations in the effluent discharged to the Grand River were higher than 20 mgN-NH4+/L and the δ15NNH4+ varied between +4 and +10‰. The nitrate concentration in the effluent was frequently between 2 and 4 mgN-NO3-/L and the δ15NNO3- from -6 to +1‰. In the 5700 m reach of the river downstream of the Kitchener wastewater treatment plant, the ammonium concentration decreased to between 2 to 0.5 mgN-NH4+/L and the δ15NNH4+ increased from +5‰ to +30‰. After upgrades (2013), the ammonium concentration in the effluent was low (≤ 6 mgN-NH4+/L) due to more efficient ammonium oxidation (and possibly volatilization and assimilation) and the δ15NNH4+ was ≈23‰, increasing to +30‰. After upgrades, the nitrate concentration in the effluent was 22 (±5) mgN-NO3-/L, and the δ15NNO3- downstream of the Kitchener wastewater treatment plant was between +11 to +14‰. After the upgrades, the nitrate concentration downstream of the outfall from the Kitchener wastewater treatment plant varied likely influenced by intra-annual variations (seasonal variation in temperature) and inter-annual variations (variable river discharge). Downstream of the Kitchener wastewater treatment plant effluent, the dissolved inorganic nitrogen did not return to previously observed background level. The observed differences in the dissolved inorganic nitrogen concentrations among seasons and years were not only attributed to changes in the quality of the WTP’s effluent, but also a result of upstream nitrate inputs from agricultural sources. Ammonium assimilation by epilithon was measured in experimental conditions by blocking bacterial oxidation with a chemical inhibitor (acetylene). Ammonium assimilation was observed at velocities above 1 μm N-NH4+ h-1, with a calculated ammonium assimilation rates from 377 to 519 um N m-2 h-1. Nitrate assimilation rates were calculated to be 58 to 65 um N m-2 h-1. Thus, epilithon assimilation contributed from 26% to 100% of the ammonium loss in each experimental unit. Ammonia volatilization in the Grand River downstream of the effluent before upgrades was estimated to range between 0.61 and 0.13 ugN-NH3/L per metre, or 0.18 to 0.04 ugN-NH3/L per second; representing a decrease of approximately 50% of the ammonia discharged from the Kitchener wastewater treatment plant. This is the first time that ammonia volatilization is estimated for a river receiving wastewater treatment plant effluent. Additionally, the ammonia isotopic fractionation factor due to volatilization (αvolatilization) was calculated experimentally as 1.019 (±0.0024) at pH 8.5, and the kinetic and equilibrium isotopic fractionation factors were calculated as αequlibrium=1.036 (±0.0024) and αkinetic=1.050 (±0.0024). A box model that uses ammonium and nitrate concentrations and isotopes of both ammonium and nitrate for estimating the rates of these processes in rivers shows that, before upgrades, the rate constant for gas exchange and ammonium assimilation were similar, however, the change in concentration was larger for ammonium assimilation. After upgrades, the rate constant for nitrification was one order of magnitude higher than before upgrades. The rates estimated by the model for each process , likely changed after upgrades due to the reduced mass of ammonium available for volatilization, oxidation and assimilation. The box model provided constant rates simultaneously estimated for the three processes; thus, the differences between the observed data in this research and the box model are assumed to be the result of: i) overestimated volatilization, ii) the experimentally measured assimilation on epilithon only and iii) the propagation of the error. Due to the separation between the ammonium (δ15NNH4+) and the macrophytes isotopic composition (δ15NTN), it is proposed that some macrophytes and possibly periphyton can be used as an environmental archive that allows one to observe the effects of the wastewater treatment plant effluent discharged into the Grand River. This archive can be used as tool to complement water quality monitoring for assessing changes in water chemistry of rivers and streams receiving wastewater treatment plant effluents. The most important contribution of this thesis is that it provides a well-documented before-and-after case study of the effects of WWTPs upgrades on the dissolved inorganic nitrogen cycling in an anthropogenically-impacted river. As such, the research provides valuable information that allows regulatory agencies and water managers (i.e., the Region of Waterloo, the Grand River Conservation Authority) to evaluate the impacts and effectiveness of potential upgrades at wastewater treatment plants in order to understand the changes in nitrogen concentrations and loads in receiving waters. This case study can be useful where regional municipalities or regulatory agencies plan to upgrade WTP’s in areas with similar geographic and climatic conditions as the observed at in the Central Grand River; however, sampling and monitoring protocols must be designed on a site by site basis taking into consideration baseline conditions and the actual objectives of the final users

Smart vest for respiratory rate monitoring of COPD patients based on non-contact capacitive sensing

In this paper, a first approach to the design of a portable device for non-contact monitoring of respiratory rate by capacitive sensing is presented. The sensing system is integrated into a smart vest for an untethered, low-cost and comfortable breathing monitoring of Chronic Obstructive Pulmonary Disease (COPD) patients during the rest period between respiratory rehabilitation exercises at home. To provide an extensible solution to the remote monitoring using this sensor and other devices, the design and preliminary development of an e-Health platform based on the Internet of Medical Things (IoMT) paradigm is also presented. In order to validate the proposed solution, two quasi-experimental studies have been developed, comparing the estimations with respect to the golden standard. In a first study with healthy subjects, the mean value of the respiratory rate error, the standard deviation of the error and the correlation coefficient were 0.01 breaths per minute (bpm), 0.97 bpm and 0.995 (p < 0.00001), respectively. In a second study with COPD patients, the values were -0.14 bpm, 0.28 bpm and 0.9988 (p < 0.0000001), respectively. The results for the rest period show the technical and functional feasibility of the prototype and serve as a preliminary validation of the device for respiratory rate monitoring of patients with COPD.Ministerio de Ciencia e Innovación PI15/00306Ministerio de Ciencia e Innovación DTS15/00195Junta de Andalucía PI-0010-2013Junta de Andalucía PI-0041-2014Junta de Andalucía PIN-0394-201

The taxonomy of Fragilaria construens var. subsalina and two morphologically related new taxa

p. 44The taxonomy of Fragilaria construens var. subsalina and two morphologically related new taxaS

Hispanic Health in the USA: A Scoping Review of the Literature

Hispanics are the largest minority group in the USA. They contribute to the economy, cultural diversity, and health of the nation. Assessing their health status and health needs is key to inform health policy formulation and program implementation. To this end, we conducted a scoping review of the literature and national statistics on Hispanic health in the USA using a modified social-ecological framework that includes social determinants of health, health disparities, risk factors, and health services, as they shape the leading causes of morbidity and mortality. These social, environmental, and biological forces have modified the epidemiologic profile of Hispanics in the USA, with cancer being the leading cause of mortality, followed by cardiovascular diseases and unintentional injuries. Implementation of the Affordable Care Act has resulted in improved access to health services for Hispanics, but challenges remain due to limited cultural sensitivity, health literacy, and a shortage of Hispanic health care providers. Acculturation barriers and underinsured or uninsured status remain as major obstacles to health care access. Advantageous health outcomes from the “Hispanic Mortality Paradox” and the “Latina Birth Outcomes Paradox” persist, but health gains may be offset in the future by increasing rates of obesity and diabetes. Recommendations focus on the adoption of the Health in All Policies framework, expanding access to health care, developing cultural sensitivity in the health care workforce, and generating and disseminating research findings on Hispanic health

Sistemas de evaluación flexibles como instrumento de mejora de los resultados académicos de los estudiantes

Esta comunicación continúa describiendo la experiencia de los firmantes en la aplicación de las nuevas metodologías docentes descritas en una comunicación anterior [1]. En primer lugar se recuerdan dichas nuevas metodologías y se resumen los resultados obtenidos con la aplicación de las mismas en los últimos cursos académicos. Se ha constatado en la práctica que, tanto el aprendizaje efectivo del alumno como sus resultados académicos alcanzados, dependen fuertemente del sistema de evaluación adoptado, condicionando incluso la estrategia de estudio y seguimiento de la asignatura por parte del alumno. En base a ello, y siguiendo las tendencias de autonomía del estudiante en su aprendizaje, auspiciadas por el Espacio Europeo de Educación Superior, se ha propuesto en el curso académico actualmente vigente (2012-2013) un nuevo sistema de evaluación más flexible que, intentando medir objetivamente el rendimiento de los estudiantes, le motive a éste a configurar de forma voluntaria las distintas actividades valorables en los distintos componentes de la evaluación. El objetivo principal de este nuevo sistema es reducir la tasa de abandono prematuro de la asignatura por parte de los estudiantes y la consecuente mejora de sus resultados académicos en la misma. REFERENCIAS. [1] RODRÍGUEZ GARCÍA, E. A. CARRILLO ANDRÉS, A. SERRANO CASARES, F. DOMÍNGUEZ MUÑOZ, F. "La evaluación continua y la tutoría virtual como herramientas eficientes en el proceso de enseñanza-aprendizaje de los estudiantes”. En Actas VII Congreso Nacional de Ingeniería Termodinámica, (Bilbao 15, 16 y 17 de junio de 2011)

Raytracing optical analysis of a solar funnel cooker

Funnel type solar cookers rely on a multifaceted reflector to concentrate solar radiation on a cooking pot that is placed inside a transparent enclosure to create a greenhouse effect. This work aims to analyze the optical performance of this type of solar cooker using raytracing techniques. The open source Soltrace software tool is used to create an optical model of a solar funnel cooker. Numerous raytracing simulations are conducted in order to complete a parametric analysis of the optical performance against a set of influence variables, such as the elevation angle, sun tracking errors, optical quality of the different elements involved ( reflectors, greenhouse, cooking pot), etc.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Hyperparameter Tuning and Automatic Image Augmentation for Deep Learning-Based Angle Classification on Intraoral Photographs-A Retrospective Study.

We aimed to assess the effects of hyperparameter tuning and automatic image augmentation for deep learning-based classification of orthodontic photographs along the Angle classes. Our dataset consisted of 605 images of Angle class I, 1038 images of class II, and 408 images of class III. We trained ResNet architectures for classification of different combinations of learning rate and batch size. For the best combination, we compared the performance of models trained with and without automatic augmentation using 10-fold cross-validation. We used GradCAM to increase explainability, which can provide heat maps containing the salient areas relevant for the classification. The best combination of hyperparameters yielded a model with an accuracy of 0.63-0.64, F1-score 0.61-0.62, sensitivity 0.59-0.65, and specificity 0.80-0.81. For all metrics, it was apparent that there was an ideal corridor of batch size and learning rate combinations; smaller learning rates were associated with higher classification performance. Overall, the performance was highest for learning rates of around 1-3 × 10-6 and a batch size of eight, respectively. Additional automatic augmentation improved all metrics by 5-10% for all metrics. Misclassifications were most common between Angle classes I and II. GradCAM showed that the models employed features relevant for human classification, too. The choice of hyperparameters drastically affected the performance of deep learning models in orthodontics, and automatic image augmentation resulted in further improvements. Our models managed to classify the dental sagittal occlusion along Angle classes based on digital intraoral photos

Uso de la tableta digital en las clases de termotecnia

La tecnología de la tableta digital, tableta gráfica, o simplemente tableta, es conocida desde hace tiempo y es muy común en diseño y arte. Sin embargo todavía es muy poco utilizada en el ámbito académico, a pesar de que ofrece indudables ventajas. La tableta gráfica combina las mejores características de la pizarra tradicional (desarrollo espontáneo en tiempo real de la clase) junto a las de los modernos medios visuales (facilidad para integrar material complejo como gráficas, imágenes, colores, etc.). A esto se suma la posibilidad de salvar el trabajo de clase y publicarlo posteriormente. El objetivo de esta comunicación es exponer la experiencia en el uso de la tableta durante un curso de Termotecnia de 2º curso del Grado de Ingeniería en Tecnologías Industriales de la Universidad de Málaga. Los resultados de la encuesta de evaluación hecha a los estudiantes muestran una percepción general muy positiva del uso de esta tecnología en las clases. No obstante, es necesario prestar atención a ciertos aspectos técnicos y de manejo por parte del profesorado para evitar problemas y desarrollar todo su potencial.Campus de Excelencia Andalucía Tec

Identificación de errores conceptuales comunes en estudiantes de Termodinámica Básica

Se investigan los preconceptos sobre calor y temperatura que tienen los alumnos de ingeniería antes de recibir formación en Termodinámica. El diagnóstico se realiza mediante un cuestionario, pasado a principios de curso. En esta comunicación se resumen los resultados de una prueba realizada con 206 estudiantes. Se cuantifica la frecuencia de diferentes tipos de error conceptual.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec