Modeling of carbon monoxide dispersion around the urban tunnel portals

The aim of this study is to investigate the problems caused by discharge of polluted air from tunnels into the environment with a specific focus on residential areas. In city tunnels, portal or stacks, pollutant management is a big challenge. Nowadays, air quality management, particularly in urban tunnels, is considered as a part of the ventilation system design. The goal is to see the environmental impacts beforehand. From environmental aspects, preventive measures are required either inside or outside the tunnel in some cases. Niayesh tunnel in Tehran is taken as a case for proving the objectives presented in this study. Concentration of carbon monoxide at the vicinity of the portals is calculated using the proper dispersion simulation. The results of dispersion modeling for the assumed worst case of ventilation can help to understand the environmental impact of ventilation. The worst traffic emissions for a congested traffic scenario,are selected as an emission source for dispersion modeling. According to the traffic condition and fleet composition, the crucial emission extracted from the tunnel is carbon monoxide. Therefore, the performed simulation only focuses on carbon monoxide dispersion modeling. From the other side, carbon monoxide is taken as a demonstration pollutant, because it is inert and chemical reactions can be neglected in short-term considerations. A lagrangian model composed of Graz Lagrangian Model and Graz Mesoscale Model is used for flow-field and dispersion calculations

Air quality in and around traffic tunnels

The National Health and Medical Research Council (NHMRC), in collaboration with the Department of Health and Ageing, commissioned a systematic review of national and international literature and practices in relation to air quality in and around traffic tunnels. This review formed the basis of a national NHMRC workshop attended by experts from the health and environment sectors, as well as representatives of government agencies and consumer groups. The outcomes of the review, workshop and subsequent submissions were analysed to inform the development of the Air Quality in and around Traffic Tunnels - Final Report. This Report evaluates the factors associated with poor air quality in and around traffic tunnels and the subsequent health effects resulting from exposure to air pollution

Fugitive emissions of particles to atmosphere: characterization, impacts and mitigation

Doutoramento em Ciências e Engenharia do AmbienteEsta tese visa caracterizar a qualidade do ar na região de Setúbal, avaliar os impactos das partículas na qualidade do ar e na saúde humana, identificar as fontes de emissão localizadas na região, avaliar o contributo das emissões fugitivas para a degradação da qualidade do ar e identificar ações mitigadoras que potenciem uma redução das concentrações de partículas na atmosfera. Para alcançar os objetivos propostos integraram-se diferentes técnicas de medição e de análise de partículas atmosféricas - amostradores de partículas em filtros, instrumentos de leitura direta de poluentes e de variáveis meteorológicas, técnicas analíticas nucleares e cromatografia iónica - e vários modelos matemáticos, tais como modelos no recetor, de dispersão e de dispersão inversa. O estudo da qualidade do ar no centro urbano-industrial de Setúbal, ao longo de 9 anos (2003-2012), permitiu constatar que as concentrações de partículas apresentaram uma tendência decrescente, devido a razões tecnológicas e económicas. No entanto, a concentração de material particulado em suspensão na atmosfera continua a não cumprir os valores guia da Organização Mundial de Saúde, existindo associações positivas entre os níveis de concentração de partículas e as admissões hospitalares, relacionadas com doenças respiratórias. Através da utilização de modelos de qualidade do ar identificou-se o tráfego automóvel como a principal fonte de emissão no centro urbano de Setúbal. Na zona industrial da Mitrena verificou-se que o aerossol secundário e o aerossol mineral, resultante da ressuspensão e proveniente de emissões fugitivas, apresentam a maior contribuição para a massa de material particulado com um diâmetro equivalente inferior a 10 μm (PM10). As emissões fugitivas têm um papel muito relevante na qualidade do ar na zona da Mitrena contribuindo, em média, para 20% dos níveis de PM10. Esta tese desenvolveu metodologias para a caracterização de emissões fugitivas em portos e analisou as características físicas e químicas dessas emissões. Demonstrou que existe um aumento significativo das concentrações de material particulado e elementos químicos durante o processo de manuseamento de materiais a granel e que esse aumento depende das características químicas e granulométricas dos materiais, das condições meteorológicas e dos procedimentos utilizados pelos operadores do porto. O resultado deste estudo constitui um importante contributo para a adoção de medidas de mitigação de material particulado no ar ambiente, assentes fundamentalmente nos processos de carga e descarga, armazenamento e transporte associados aos portos.This thesis aims to characterize air quality in Setúbal region, to assess the impacts of particles on air quality and on human health, to identify emission sources, to evaluate the contribution of fugitive emissions to the degradation of air quality and to identify mitigation actions that promote a reduction of particulate matter concentrations in the air. In order to reach the proposed objectives different techniques were used to monitor and characterize atmospheric particles, such as samplers to collect particles in filters, direct pollutant reading equipment, meteorological instruments, nuclear analytical techniques and ion chromatography. Moreover, receptor, dispersion and inverse dispersion models were used to assess the contribution of emission sources to the air quality. The study of air quality in the urban-industrial center of Setúbal, along 9 years (2003-2012), showed that the concentration of particles presented a decreasing trend, due to technological and economic reasons. However, it has been found that the concentration of suspended particulate matter in the air continues to fail accomplishing the World Health Organization guidelines, with positive associations between particle levels and hospital admissions related to respiratory diseases. The use of air quality models allowed identifying road traffic as the main emission source in the urban center of Setúbal. In Mitrena industrial zone, the secondary aerosol and the mineral aerosol, resulting from dust resuspension and fugitive emissions, have shown the greatest contribution to the total mass of PM10. Fugitive emissions play a very important role in the air quality in Mitrena contributing on average to 20% of the PM10 levels. This thesis developed methodologies for the characterization of fugitive emissions in harbors and analyzed the physical and chemical characteristics of these emissions. Results show that there is a significant increase of particulate matter and chemical elements concentrations during the handling of bulk material and this increase depends on the chemical and granulometric characteristics of the materials, weather conditions and procedures used by the harbor operators. This study identified particulate matter in the air mitigation measures, which are mainly based on loading, unloading, storage and transportation processes associated with harbor activities

Sistema de evaluación de la dispersión episódica de contaminantes atmosféricos

Frente a la contaminación de otros medios (aguas, suelos), en la era preindustrial se había considerado a la atmósfera como un medio de depuración de contaminantes suficientemente eficaz como para que, salvo en contadas excepciones, las emisiones de contaminantes a la atmósfera resultasen inocuas para el medio y las personas; reduciéndose a un problema de molestias (olores, visibilidad), sin mayores consecuencias. Esta consideración errónea agudizó el problema de la contaminación atmosférica con la introducción de la máquina de vapor, origen de la revolución industrial, para cuyo funcionamiento comenzaron a quemarse grandes cantidades de carbón; a lo que hay que sumar el uso de otros combustibles fósiles en la industria y transporte, el manejo y emisión de sustancias procedentes de la industria química, y de otras actividades humanas. A partir de ese momento, la preocupación por la calidad del aire que respiramos ha ido pareja al reconocimiento de las incertidumbres en los procesos atmosféricos que afectan a los contaminantes, de carácter altamente no lineal y que experimentan grandes variaciones en función de la dinámica meteorológica, ya de por sí compleja. Estos procesos complejos, sin embargo, son los que permiten la depuración de los contaminantes en la atmósfera y, en consecuencia, la minoración de su impacto; por lo que se ha reconocido la necesidad de conocerlos y, cuando era posible, cuantificarlos. Así que, el conocimiento de los procesos atmosféricos relacionados con la contaminación atmosférica partió inicialmente del análisis de datos experimentales de campo, de una parte, y de modelos teóricos de los procesos atmosféricos y su posible relación con la dispersión física de los contaminantes. La simplicidad de las soluciones analíticas de dichos modelos teóricos, sin embargo, dificultaba su aplicación a problemas reales

African Handbook of Climate Change Adaptation

This open access book discusses current thinking and presents the main issues and challenges associated with climate change in Africa. It introduces evidences from studies and projects which show how climate change adaptation is being - and may continue to be successfully implemented in African countries. Thanks to its scope and wide range of themes surrounding climate change, the ambition is that this book will be a lead publication on the topic, which may be regularly updated and hence capture further works. Climate change is a major global challenge. However, some geographical regions are more severly affected than others. One of these regions is the African continent. Due to a combination of unfavourable socio-economic and meteorological conditions, African countries are particularly vulnerable to climate change and its impacts. The recently released IPCC special report "Global Warming of 1.5º C" outlines the fact that keeping global warming by the level of 1.5º C is possible, but also suggested that an increase by 2º C could lead to crises with crops (agriculture fed by rain could drop by 50% in some African countries by 2020) and livestock production, could damage water supplies and pose an additonal threat to coastal areas. The 5th Assessment Report produced by IPCC predicts that wheat may disappear from Africa by 2080, and that maize— a staple—will fall significantly in southern Africa. Also, arid and semi-arid lands are likely to increase by up to 8%, with severe ramifications for livelihoods, poverty eradication and meeting the SDGs. Pursuing appropriate adaptation strategies is thus vital, in order to address the current and future challenges posed by a changing climate. It is against this background that the "African Handbook of Climate Change Adaptation" is being published. It contains papers prepared by scholars, representatives from social movements, practitioners and members of governmental agencies, undertaking research and/or executing climate change projects in Africa, and working with communities across the African continent. Encompassing over 100 contribtions from across Africa, it is the most comprehensive publication on climate change adaptation in Africa ever produced