Evaluación ambiental por medio del análisis de ciclo de vida del relleno sanitario del distrito de Nauta, en Loreto

La generación y tratamiento de los residuos sólidos municipales es un problema con el que ha tenido que lidiar toda civilización desde sus inicios. Desde el siglo XX el manejo y control de ellos se fue perfeccionando a lo largo de Europa de modo que los impactos a la salud humana y al ambiente se vean minimizados. Por ello, se inició la migración del uso de rellenos sanitarios a sistemas de tratamiento más avanzados e integrales, de modo que se pueda optimizar el consumo energético y mejorar el desempeño socio-económico y ambiental de estos. Sin embargo, la realidad al día de hoy en el Perú es muy distante de esto. Actualmente, el país está buscando hacer la transición de la disposición en botaderos informales a rellenos sanitarios, por lo que se están abriendo nuevos emplazamientos a lo largo y ancho del país. Por esto y con el fin de poder identificar los principales impactos ambientales y tomar medidas de mitigación adecuadas, se ha realizado una evaluación ambiental por medio del Análisis de Ciclo de Vida de un relleno sanitario ubicado en la ciudad de Nauta (Loreto), en la selva amazónica. El ciclo de vida del relleno sanitario incluyó las etapas desde la extracción de los materiales, construcción del emplazamiento y operación, hasta el cierre del relleno. La unidad funcional estudiada fue de 1 tonelada de residuos sólidos municipales generados en la ciudad de Nauta y su desempeño a lo largo de 100 años. Se utilizó el software de cálculo especializado en sistemas de tratamiento de residuos sólidos EASETECH para llevar a cabo el modelado del sistema. Se modelaron 5 escenarios: un botadero abierto poco profundo, un botadero abierto profundo, el relleno sanitario actual, en el que no se realiza tratamiento de biogás, y dos escenarios de mejora: uno en el que se realiza combustión del biogás y otro en el que se realiza recuperación de energía. Para evaluar los impactos se emplearon 9 categorías de impacto, siendo 1 de ellas Cambio Climático con el método IPCC 2013 y las restantes del método ReCiPe 2008. Los principales resultados muestran que el impacto total del relleno en la categoría de Cambio Climático asciende a 1376 kg CO2-eq por unidad funcional, y se reduce a 696 y 355 kg CO2-eq si se implementa la quema de biogás y recuperación de energía, respectivamente. Asimismo, la mayor parte de las emisiones se generan a lo largo de los primeros 5 años debido a las condiciones climáticas calurosas y húmedas de la selva amazónica. En cuanto a las categorías de impacto restantes, estas se ven incrementadas en gran medida por las elevadas precipitaciones de la región. Además, la migración de botadero informales a rellenos sanitarios, si bien incrementa el impacto en Cambio Climático, reduce en hasta 4 órdenes de magnitud los impactos en la mayoría de categorías restantes, lo que implicaría definitivamente un beneficio ambiental significativo. Finalmente, se concluye que se deben realizar mejoras en la infraestructura actual y en el manejo del relleno para lograr reducir impactos en eutrofización y toxicidad. De igual manera, para poder reducir el impacto en la categoría de Cambio Climático se deben implementar sistemas de tratamiento de biogás. El Ministerio del Ambiente debe tomar en consideración estos hallazgos para poder mejorar la propuesta de las Contribuciones Nacionales Determinadas ante el Acuerdo de París, para así poder cumplir el compromiso tomado. Esto se debe a que la transición de botaderos abiertos a rellenos sanitarios sin tratamiento de biogás no reduce el potencial de calentamiento global, sino lo incrementa. Por último, se puede afirmar que los resultados de la presente investigación marcan un hito en el rubro de los residuos sólidos y deben formar la base de futuras investigaciones a desarrollar en el país.Tesi

Life cycle assessment of low-cost technologies for digestate treatment and reuse in small-scale farms in Colombia

Anaerobic digestion (AD) is a practice that is mainly carried out to give treatment to different kinds of organic residues (e.g. food waste, manure, agricultural residues) in order to obtain biogas and produce bioenergy. Because of its nature, the generated biogas is considered to be a renewable energy source, henceforth an important strategy in the fight against climate change. Anaerobic digesters carry out the AD process under specific conditions to allow microbial communities to develop and decompose organic matter (OM) into the desired biogas. In addition to biogas, the degradation of organic waste in the digester also produces a liquid effluent (digestate) (U.S. EPA, 2021). This exiting digestate is a combination of solid and liquid fractions from the AD process, rich in nutrients and OM. Because of its characteristics, digestate is a valuable effluent, as it can be used as organic fertilizer and spread on agricultural lands (Panuccio, et al., 2018). The use of digestate as fertilizer has several benefits, such as boosting crop growth and quality, acting as soil amender, or mitigating greenhouse gas (GHG) emissions (Wang & Lee, 2021). Nonetheless, depending on the characteristics of the feedstock and on the further use of the digestate, it has to undergo treatment and/or stabilization to avoid the spreading of pathogens, toxic metals or other pollutants that might be present in it (Cucina et al., 2021; Wang & Lee, 2021). For this study, this rationale has been implemented in Colombian low-income small-scale farms. Colombia is a country with a great agricultural tradition, considering that by 2017 more than 15% of the domestic extraction of the country was related to the agricultural industry (Material Flows, 2019). Nevertheless, even though Colombia has expected a considerable growth throughout the past 30 years, up to 50% of its population is considered to live in poverty (Garfí, et al., 2019). Consequently, low income populations have to rely on self-sufficient farming and traditional fuels such as firewood and dry dung for cooking and house warming. For these reasons, low-cost digesters have been implemented in several Colombian communities to cope with homely energy demands and substitute the risky traditional fuels that end up affecting both people and the local environment (Garfí, et al., 2011). It is in this context that several studies have been carried out to analyze the environmental performance of anaerobic digesters in rural conditions in the Andes (Garfí, et al., 2012; Garfí, et al., 2019; Mendieta, et al., 2021). However, these studies have focused on the implementation of the digester and the biogas use, but have not deepened in the treatment and use of the digestate. Even though these studies have considered a direct use of digestate, other authors have stated that, despite the benefits of this practice, it might have associated risks if no further treatment of the digestate is carried out prior to its application on land (Cucina, et al., 2021). Therefore, the main objective of this study is to analyze the environmental impacts of three alternative scenarios for the digestate treatment and reuse from a low-cost anaerobic digester: 1) digestate treatment with a sand filter and its reuse as biofertilizer 2) digestate treatment with a vermifilter and its reuse as biofertilizer; 3) a baseline scenario without digestate treatment (direct use on land).The research was funded by the Centre for Development Cooperation (CCD) of the Technical University of Catalonia (UPC) (CCD2021-J004), the Universidad Industrial de Santander, Colombia (Proyecto 2504), and the Ministry of Science and Technology of Colombia (Contrato número 583-2020). Marianna Garfí are grateful to the Government of Catalonia (Consolidated Research Group 2017 SGR 1029), and to the Spanish Ministry of Economy and Competitiveness (RYC-2016 20059).Postprint (published version

Environmental performance of peruvian waste management systems under a life cycle approach

Peru generated in 2014 a total of 7.5 million metric tons of municipal solid waste (MSW). Of these, 47 % of residues ended up in open dumpsites and only 21 % were sent to controlled landfills. Efforts must be made to conduct a change from open dumpsites to sanitary landfills, reaching an adequate and sustainable waste management system. This study aims at meeting this challenge by means of the Life Cycle Assessment (LCA) methodology. In particular, the objective of this study is to develop a life cycle model that will allow the estimation of environmental impacts linked to waste landfilling in Peru, and to compare in further studies alternatives to determine a more environmentally sustainable solution. The model is flexible in order to be adapted to the three main geo-climatic regions in Peru: the hyper-arid coast, the Andean Highlands and the Amazon Rainforest. The life cycle model was developed with the EASETECH software, taking into account the phases of construction, operation and end-of-life the Peruvian landfills. The main parameters of this model include waste composition and the characteristics and treatment of the leachate and landfill gas, taking into consideration local parameters such as temperature, humidity and precipitation intensity. The model lays the foundation stone to determine the main hotspots in Peruvian sanitary landfills. This information will allow achieving an adequate and sustainable waste management by proposing improvement measures to help stakeholders in the decision-making process

Production and calibration of the first HEFT hard x-ray optics module

Complete hard X-ray optics modules are currently being produced for the High Energy Focusing Telescope (HEFT), a balloon born mission that will observe a wide range of objects including young supernova remnants, active galactic nuclei, and galaxy clusters at energies between 20 and 70 keV. Large collecting areas are achieved by tightly nesting layers of grazing incidence mirrors in a conic approximation Wolter-I design. The segmented layers are made of thermally-formed glass substrates coated with depth-graded multilayer films for enhanced reflectivity. Our novel mounting technique involves constraining these mirror segments to successive layers of precisely machined graphite spacers. We report the production and calibration of the first HEFT optics module

Screening for Type 1 Diabetes in the General Population:A Status Report and Perspective

Most screening programs to identify individuals at risk for type 1 diabetes have targeted relatives of people living with the disease to improve yield and feasibility. However, ∼90% of those who develop type 1 diabetes do not have a family history. Recent successes in disease-modifying therapies to impact the course of early-stage disease have ignited the consideration of the need for and feasibility of population screening to identify those at increased risk. Existing population screening programs rely on genetic or autoantibody screening, and these have yielded significant information about disease progression and approaches for timing for screening in clinical practice. At the March 2021 Type 1 Diabetes TrialNet Steering Committee meeting, a session was held in which ongoing efforts for screening in the general population were discussed. This report reviews the background of these efforts and the details of those programs. Additionally, we present hurdles that need to be addressed for successful implementation of population screening and provide initial recommendations for individuals with positive screens so that standardized guidelines for monitoring and follow-up can be established

Nitration of Wheat Amylase Trypsin Inhibitors Increases Their Innate and Adaptive Immunostimulatory Potential in vitro

Amylase trypsin inhibitors (ATI) can be found in all gluten containing cereals and are, therefore, ingredient of basic foods like bread or pasta. In the gut ATI can mediate innate immunity via activation of the Toll-like receptor 4 (TLR4) on immune cells residing in the lamina propria, promoting intestinal, as well as extra-intestinal, inflammation. Inflammatory conditions can induce formation of peroxynitrite (ONOO−) and, thereby, endogenous protein nitration in the body. Moreover, air pollutants like ozone (O3) and nitrogen dioxide (NO2) can cause exogenous protein nitration in the environment. Both reaction pathways may lead to the nitration of ATI. To investigate if and how nitration modulates the immunostimulatory properties of ATI, they were chemically modified by three different methods simulating endogenous and exogenous protein nitration and tested in vitro. Here we show that ATI nitration was achieved by all three methods and lead to increased immune reactions. We found that ATI nitrated by tetranitromethane (TNM) or ONOO− lead to a significantly enhanced TLR4 activation. Furthermore, in human primary immune cells, TNM nitrated ATI induced a significantly higher T cell proliferation and release of Th1 and Th2 cytokines compared to unmodified ATI. Our findings implicate a causative chain between nitration, enhanced TLR4 stimulation, and adaptive immune responses, providing major implications for public health, as nitrated ATI may strongly promote inhalative wheat allergies (baker's asthma), non-celiac wheat sensitivity (NCWS), other allergies, and autoimmune diseases. This underlines the importance of future work analyzing the relationship between endo- and exogenous protein nitration, and the rise in incidence of ATI-related and other food hypersensitivities

A Search for Dark Higgs Bosons

Recent astrophysical and terrestrial experiments have motivated the proposal of a dark sector with GeV-scale gauge boson force carriers and new Higgs bosons. We present a search for a dark Higgs boson using 516 fb-1 of data collected with the BABAR detector. We do not observe a significant signal and we set 90% confidence level upper limits on the product of the Standard Model-dark sector mixing angle and the dark sector coupling constant.Comment: 7 pages, 5 postscript figures, published version with improved plots for b/w printin