Estratégias de apoio para melhorar a qualidade do ar em áreas portuárias

Despite their key contribution to economic development, harbours pose environmental threat, affecting air quality, local climate, and human health, due to the release of several pollutants. Poor local air quality episodes are particularly concerning when harbours are located near densely populated urban areas, threatening inhabitants’ health. This Thesis was focused on the assessment of the impact of harbour emissions on the air quality over harbours and their surrounding urban areas, with a final goal of producing guidelines to support decision-making in the harbour sector and air quality management, using Port of Leixões as a case-study. After reviewing the state-of-the-art in this research field, a high-resolution emission inventory was developed, based on the two most used methodologies within the scientific community. Data about ship and cargo handling equipment were compiled, allowing the quantification of emissions and identification of their main sources. The comparison of the two methodologies indicates that a new harmonized methodology is recommended, besides the need of continuous update of emission factors and activity data. Having the detailed emission inventory, the community-scale webtool C-PORT was applied for the first time in European harbours to simulate the impact of the maritime emissions on local air quality. The comparison of modelled and observed values validated its application for the case study of Port of Leixões. The highest PM10 concentrations were found near the South Container Terminal of Port of Leixões, while NOx concentrations above 100 µg/m3 were also found near the highway. Land-based emission sources exhibited the highest contribution (around 80 %) to the PM10 concentrations in the study area, while 50 % of NOx concentration was due to docked ships. Mitigation measures were investigated and assessed to improve air quality in harbours and their surroundings. In a case-study, pollutant dispersion was addressed, aiming to control fugitive petcoke emissions and their impact on Port of Aveiro’s neighbour communities. Optimal structure, size and position of a physical barrier were defined based on numerical and physical modelling, achieving a maximum reduction in petcoke dust reaching the nearby residential area of 74 – 88 % for the most frequent/critical wind directions. The studied barrier has been implemented in the field and monitoring campaigns are currently being carried out to assess its effectiveness.Apesar do seu papel-chave no desenvolvimento económico, os portos marítimos constituem uma ameaça ambiental, com impactes na qualidade do ar, clima local, e saúde humana, devido à emissão de inúmeros poluentes. Episódios de má qualidade do ar a nível local são particularmente preocupantes no caso de portos localizados nas imediações de áreas urbanas densamente povoadas, pondo em risco a saúde dos habitantes locais. Esta Tese focou-se no impacte das emissões portuárias na qualidade do ar em portos e suas vizinhanças urbanas. O objetivo final foi a produção de recomendações de suporte à tomada de decisão no setor portuário e gestão da qualidade do ar, usando o Porto de Leixões como caso-de-estudo. Após uma revisão do estado-da-arte neste campo, foi desenvolvido um inventário de emissões de alta-resolução, aplicando as duas metodologias mais frequentemente usadas na comunidade científica. Foram compilados dados sobre navios e equipamentos portuários, permitindo a quantificação das emissões e identificação das suas fontes maioritárias. Deste procedimento resultaram recomendações sobre o desenvolvimento de uma nova metodologia harmonizada. Ficou ainda evidenciada a relevância da atualização dos fatores de emissão e dos dados disponíveis sobre as diferentes atividades portuárias. Dispondo deste inventário de emissões, o C-PORT, uma ferramenta web de escala comunitária, foi aplicado pela primeira vez em portos europeus, para simular o impacte das emissões marítimas na qualidade do ar local. A comparação dos valores modelados com medições de campo validou a aplicação desta ferramenta ao caso-de-estudo do Porto de Leixões. A concentração mais elevada de PM10 foi registada no Terminal de Contentores Sul, registando-se também elevada (> 100 µg/m3 ) concentração de NOx junto à autoestrada vizinha. A maior contribuição (cerca de 80 %) para a emissão global de PM10 na área de estudo adveio de fontes de emissão terrestres, enquanto os navios atracados contribuíram com cerca de 50 % das emissões de NOx. Esta Tese inclui a análise de medidas de mitigação capazes de melhorar a qualidade do ar em portos marítimos e sua vizinhança. O caso-de-estudo apresentado foca-se na dispersão de poluentes, com o intuito de controlar a emissão de partículas de petcoke do Porto de Aveiro, e o seu impacte nas comunidades vizinhas. Com esse objetivo, foi estudada, através de simulação física e numérica, a composição, dimensão e posicionamento de uma barreira física. A solução otimizada permitiu reduzir em 74 % – 88 % para as direções de vento mais frequentes/críticas nesta região, estando atualmente implementada no terreno.Programa Doutoral em Ciências e Engenharia do Ambient

Biocatálise aplicada à valorização de óleos alimentares usados

Mestrado em Engenharia do AmbienteO crescente consumo de energia, bem como a possibilidade de esgotamento dos recursos não renováveis, tem fomentado a busca de fontes de energia alternativas. O biodiesel é um biocombustível obtido a partir de fontes renováveis e a sua utilização permite reduzir as emissões de gases com efeito de estufa. Nos últimos anos tem-se produzido biodiesel a partir de óleos alimentares usados (OAU), sendo que com esta aplicação valoriza-se um resíduo e simultaneamente produz-se um combustível “verde”. O biodiesel é produzido através das reações de transesterificação e/ou esterificação entre triglicerídeos e/ou ácidos gordos livres e um álcool, na presença de um catalisador. O rendimento do processo está estritamente relacionado com o tipo de catalisador e as condições que este opera. O principal objetivo do presente trabalho consistiu na avaliação do efeito de alguns parâmetros operacionais no desempenho de uma lípase imobilizada (Novozyme® 435), nomeadamente: (i) índice de acidez do óleo, (ii) razão mássica de enzima/óleo e (iii) método regeneração da enzima com vista à sua reutilização. Também foi objeto de estudo do presente trabalho a produção em contínuo, num (bior)reator tubular de leito fixo, de ésteres metílicos de ácidos gordos (FAME) usando a referida enzima. Registou-se um aumento rendimento em com o incremento do índice de acidez do óleo usado, o que indicia que a enzima catalisa simultaneamente as reações de esterificação e transesterificação. Relativamente à razão mássica de enzima/óleo, dentro da gama testada verificou-se um aumento do rendimento em FAME com a concentração da enzima em meio reacional. Dos vários solventes testados, a aplicação de solvente tert-butanol na regeneração (com incubação) da enzima foi o que melhores resultados teve. Finalmente, os resultados obtidos no ensaio de produção de FAME num biorreator contínuo são motivadores, criando expectativas de uma possível aplicação industrial no futuro.The increasing energy consumption and the non-renewable resources depletion has encouraged the search for alternative energy sources. Biodiesel is a biofuel obtained from renewable sources which utilization allows aiming the reduction on greenhouse effect gases emissions. In the last few years, biodiesel has been produced from used cooking oil, since this application promotes the valorization of a waste and the production of a green fuel, simultaneously. Biodiesel is produced through transesterification reactions and/or esterification between triglycerides and/or fatty acids and an alcohol, in the presence of an appropriate catalyst. The efficiency of the process is strictly related with the type of catalyst and the operational conditions. The main goal of this study was to evaluate the effect of some operational parameters in an immobilized lipase’s performance (Novozyme® 435), namely: (i) oil’s acidity index, (ii) enzyme/oil mass ratio and (iii) applied treatment on the enzyme regeneration stage, in order to reutilize it. It was also a goal to study the production in a continuous regime, in a fixed bed bio(reactor), of fatty acid methyl esters (FAME) using the referred enzyme. It has been registered an increased efficiency on FAME with the oil acidity index rise, which indicates that the enzyme catalyzes simultaneously both the esterification and transesterification reactions. Concerning the enzyme/oil mass ratio , within the tested range, an increase was registered on FAME efficiency with enzyme concentration in the reactional medium. Among several solvents tested on enzyme washing, tert-butanol was the one with the better performance. Finally, the results obtained from the FAME production on a continuous bioreactor essay are motivating, creating some expectations on its possible future application at an industrial level

Impact of harbour activities on local air quality: a review

Several harbour activities cause negative environmental impacts in the harbours' surrounding areas, namely the degradation of air quality. This paper intends to comprehensively review the status of the air quality measured in harbour areas. The published studies show a limited number of available air quality monitoring data in harbours areas, mostly located in Europe (71%). Measured concentrations of the main air pollutants were compiled and intercompared, for different countries worldwide allowing a large spatial representativeness. The higher NO2 and PM10 concentrations were found in Europe - ranging between 12 and 107 μg/m3 and 2-50 μg/m3, respectively, while the higher concentrations of PM2.5 were found in Asia (25-70 μg/m3). In addition, the lower levels of SO2 monitored in recent years suggest that current mitigation strategies adopted across Europe were very efficient in promoting the reduction of SO2 concentrations. Part of the reviewed studies also estimated the contributions from ship emissions to PM concentration through the application of source apportionment methods, with an average of 5-15%. In some specific harbour areas in Asia, ships can contribute up to 7-26% to the local fine particulate matter concentrations. This review confirms that emissions from the maritime transport sector should be considered as a significant source of particulate matter in harbour areas, since this pollutant concentrations are frequently exceeding the established standard legal limit values. Therefore, the results from this review boost the implementation of mitigation measures, aiming to reduce, in particular, particulate matter emissions.publishe

Classification of critical levels of CO exposure of firefigthers through monitored heart rate

Smoke inhalation poses a serious health threat to firefighters (FFs), with potential effects including respiratory and cardiac disorders. In this work, environmental and physiological data were collected from FFs, during experimental fires performed in 2015 and 2019. Extending a previous work, which allowed us to conclude that changes in heart rate (HR) were associated with alterations in the inhalation of carbon monoxide (CO), we performed a HR analysis according to different levels of CO exposure during firefighting based on data collected from three FFs. Based on HR collected and on CO occupational exposure standards (OES), we propose a classifier to identify CO exposure levels through the HR measured values. An ensemble of 100 bagged classification trees was used and the classification of CO levels obtained an overall accuracy of 91.9%. The classification can be performed in real-time and can be embedded in a decision fire-fighting support system. This classification of FF’ exposure to critical CO levels, through minimally-invasive monitored HR, opens the possibility to identify hazardous situations, preventing and avoiding possible severe problems in FF’ health due to inhaled pollutants. The obtained results also show the importance of future studies on the relevance and influence of the exposure and inhalation of pollutants on the FF’ health, especially in what refers to hazardous levels of toxic air pollutants.publishe

Adaptation to Climate Change at Local Scale: A CFD Study in Porto Urban Area

Green infrastructures play an essential role in urban planning, namely with their potential to reduce the impact from air pollution episodes together with extreme weather events. This chapter focuses on the assessment of green infrastructures’ benefits on current and future microclimate and air quality patterns in Porto’s urban area (Portugal). The effects of green infrastructures on flow dynamics are evaluated for the baseline scenarios by means of numerical and physical simulations, using the computational fluid dynamics (CFD) model VADIS and the wind tunnel of the University of Aveiro. The baseline morphological (BM) scenario focuses on the current morphological characteristics of Porto’s urban area, while a baseline green (BG) scenario comprises the replacement of built-up areas by green areas and parks. In addition, the benefits of green infrastructures on air quality are assessed for the baseline and under future climate scenarios. The air quality simulations focus on particulate matter, one of the most critical air pollutants with severe impacts on human health. For the BM scenario, the simulated concentrations are compared with hourly averaged PM10 concentrations measured during a weekday at the air quality station located within the study domain

Assessment of source contribution to air quality in an urban area close to a harbor: case-study in Porto, Portugal

Several harbors, like the Port of Leixões (Porto, Portugal), are located near urban and industrial areas, places where residential urban areas, highways and the refinery industry coexist. The need for assessing the contribution of the port to the air quality in its vicinity around the port is the motivation for the present study. This contribution was investigated using a numerical modelling approach based on the web-based research screening tool C-PORT. The impact of the meteorological conditions (namely atmospheric stability and wind direction) was first evaluated, and the most critical conditions for pollutants dispersion were identified. The dominant wind direction, from WSW, was responsible for the transport of pollutants over the surrounding urban area, which was potentiated by the diurnal sea breeze circulation. Multiple scenario runs were then performed to quantify the contribution of each emission sector/activity (namely maritime emissions; port activities; road traffic and refinery) to the ambient air quality. The multiple scenario runs indicated that land-based emission sources at the Port (including trucks, railways, cargo handling equipment and bulk material stored) were the major contributors (approximately 80%) for the levels of surface PM10 concentrations over the study area. Whereas, the main drivers of NOX concentrations were docked ships, responsible for 55-73% of the total NOX concentrations.publishe

Mitigação de emissões marítimas e portuárias: linhas orientadoras

Um dos setores económicos que tem atraído grande atenção em termos ambientais é o setor marítimo e portuário (Dragovic et al, 2018), sobretudo devido à sua grande dependência no que diz respeito ao uso de combustíveis fósseis, o que leva a uma grande contribuição para a poluição atmosférica, concorrendo assim para a degradação da qualidade do ar (Monteiro et al, 2018; Chen et al, 2019). O transporte marítimo apresenta uma tendência de aumento, diretamente relacionada com o aumento da economia mundial e das trocas comerciais entre os vários países. Contudo, este crescimento possui um ritmo mais elevado do que a economia trazendo por isso alguns problemas (Hua et al, 2017). Estima-se que cerca de 90% de toda a troca de mercadorias e bens em todo mundo é realizada por via marítima, o que revela a importância deste setor, tornando-o no principal meio de transporte de mercadorias no mundo (IMO, 2011). A nível europeu o transporte marítimo é responsável por 75% das trocas de mercadorias no seu território (EEA, 2017). Um dos grandes problemas associados a este tipo de transporte são as emissões de poluentes atmosféricos (Anturri el al, 2016) que, segundo estudos já realizados, ocorrem na maioria dos casos a cerca de 400 km da linha de costa nas zonas de rotas internacionais (Nunes et al, 2017). Estes poluentes emitidos conseguem ser transportados com relativa facilidade para zonas costeiras povoadas trazendo assim problemas tanto a nível local, como global, para a saúde humana e ainda para os ecossistemas (Nunes et al, 2017; Hua et al, 2017). Este tipo de transporte contribui para uma grande parte das emissões antropogénicas de óxidos de enxofre (SOx) e azoto (NOx) (Lindstad et al, 2016), sendo também um dos maiores emissores de dióxido de carbono (CO2) a nível global, no setor dos transportes (Yaun, 2019). As áreas portuárias contribuem para o desenvolvimento social e económico das zonas costeiras (Merico et al, 2016), uma vez que estas encontram-se na sua grande maioria em grandes zonas de urbanização (Kozarev et al, 2014), sendo por esta razão frequente afirmar que os portos marítimos são uma extensão das cidades onde estes se encontram, podendo ainda tomar um papel importante para a prática de iniciativas de transporte sustentável (EEA, 2017).As atividades que ocorrem dentro dos portos marítimos não se prendem apenas com o transporte marítimo dentro do porto, existindo várias fontes que contribuem para a poluição atmosférica nestas áreas, que como no resto do setor encontram-se fortemente associadas ao uso de combustíveis fósseis (Kozarev et al, 2014). Existem ainda outras fontes emissoras associadas a outras atividades como a movimentação de cargas, levando a emissões fugitivas, sobretudo de material particulado (Borrego et al, 2007), responsáveis pela deterioração da qualidade do ar local afetando não só os trabalhadores, como também a população envolvente residente (NABU, 2015). A definição de estratégias de mitigação para reduzir estes problemas é um ponto fulcral para que exista não só uma harmonia entre as áreas portuárias e as zonas de urbanização envolventes, mas também ao nível do transporte marítimo internacional, de forma a se conseguir minimizar os impactos associados a este tipo de transporte e melhorar a qualidade do ar tanto ao nível local como regional. O projeto AIRSHIP – “Impacto das emissões do transporte marítimo e portuário na qualidade do ar em Portugal: cenários presente e futuro.” (www.airship.web.ua.pt), desenvolvido pelo grupo de investigação GEMAC do Departamento de Ambiente e Ordenamento da Universidade de Aveiro, teve como principal objetivo avaliar o impacto das emissões do transporte marítimo na qualidade do ar em Portugal, tendo como caso de estudo o Porto de Leixões à escala local e Portugal à escala regional, e considerando o cenário presente e futuro (com alterações climáticas). Tratou-se de um projeto financiado pela FCT e que decorreu entre 2016-2019. Este projeto, estruturado em quatro tarefas distintas, compreendeu na última tarefa a elaboração de um conjunto de medidas/estratégias mitigadoras para minimizar os impactos associados ao transporte marítimo no país. Este documento, produzido no âmbito do projeto AIRSHIP, procura assim dar resposta a este objetivo de delinear estratégias mitigadoras e boas práticas para reduzir o impacto das emissões provenientes tanto do transporte marítimo, como também de todas as atividades portuárias associadas, promovendo uma melhor gestão e proteção da qualidade do ar. Desta forma, no capítulo 2 é feita uma breve apresentação das emissões marítimas e seu impacto na qualidade do ar. No capítulo 3 é apresentado o caso de estudo do Porto de Leixões que foi usado como referência, tendo sido identificados os principais problemas existentes no porto, e definidas as melhores medidas/ estratégias para minimizar o impacto desses problemas na qualidade do ar, tanto no interior do Porto de Leixões, bem como na área envolvente. No capítulo 4, para além do foco na área portuária, foi elaborado um conjunto de estratégias mitigadoras das emissões marítimas, com foco à escala nacional.publishe

Measures to reduce air pollution caused by fugitive dust emissions from harbour activities

Emissions from harbour-related activities have an important impact on air quality; therefore, improved knowledge about the coastal microclimate and consequent air pollution dispersion patterns is of utmost importance. In recent years, residents of the southeast urban community of the Port of Aveiro (Portugal) have identified high levels of dust in and around their residences, which has raised their concern regarding the potential effects of air pollution on public health. The citizens’ complaints were linked to fugitive dust emissions from petroleum coke (petcoke), which is usually unloaded or temporarily stored outdoors in the port prior to transportation to a nearby manufacturing plant. Following this, the air quality measurements taken in the area have shown high levels of PM10 concentrations, especially when the wind blew from north and northwest directions. Furthermore, a numerical and physical modelling study has been performed in order to assess the impacts of the transport and storage of petcoke on the local air quality. The modelling results pointed out to a set of potential mitigation measures, namely the construction upwind of different barriers from the petcoke pile. This article presents the characterization of the problem and the management strategies adopted. It also presents the results of modelling assessment to select the most potential effective barrier in order to minimize petcoke dust impact on the surrounding population.publishe

Numerical and physical assessment of control measures to mitigate fugitive dust emissions from harbor activities

In recent years, the industrial demand for petcoke—a solid residue derived from the refinement of crude oil—has been growing due to its low cost. The use of petcoke is causing environmental concern associated with its high level of contaminants and air pollutant emissions, mainly particulate matter (PM). Given the impact of petcoke on the environment and human health, increased attention has been given to its production, storage, transportation, and application processes. The main goal of this work was to assess the effectiveness of placing a barrier to reduce PM emissions from petcoke in a harbor area. The Port of Aveiro, Portugal, was used as case study. Firstly, wind tunnel experiments were performed for different types of barrier to (i) assess the effect on PM emissions of different types of barriers, namely solid, porous, and raised porous barriers; (ii) determine the optimal size and location of the barrier to achieve maximum reduction of PM emissions; and (iii) estimate the impact of placing such barrier in the attenuation of petcoke emissions over the harbor area. Secondly, the numerical model VADIS (pollutant DISpersion in the atmosphere under VAriable wind conditions) was run to evaluate the effect of implementing the barrier on the local air quality. Results showed that the best solution would be the implementation of two solid barriers: a main barrier of 109 m length plus a second barrier of 30 m length. This measure produced the best results in terms of reduction of the dispersion of particulate matter from the petcoke stockpile and minimization of the PM concentrations in the harbor surrounding area.publishe

High-Resolution Analysis of Wind Flow Behavior on Ship Stacks Configuration: A Portuguese Case Study

Atmospheric emissions related to harbor-related activities can significantly contribute to air pollution of coastal urban areas and so, could have implications to the citizens’ health that live in those areas. Of great concern is the local impact of the emissions that are generated while ships are at berth, since not all types of ships switch off the main engines. This paper intends to investigate the influence of the stack configuration for generic cargo ships on the exhaust smoke dispersion, using the Port of Leixões as a case study and a series of wind tunnel experiments with support of Particle Image Velocimetry (PIV) technique. For that, different configurations of the stack of a cargo ship (in terms of height, geometry and diameter) were simulated under the typical wind conditions of the study area. The PIV results indicate negligible differences between the medium and long stack height, with the short stack height presenting a strong impact on the flow field around the stack. For the short stack height, the flow field is not only disturbed by the stack, but also by the cargo ship bridge, with both obstacles promoting disturbances on the flow field and creating a large wake turbulence effect, which is important for the downwash phenomena. Regarding the effects linked with two distinct geometries (straight or curved), the results show that the straight chimney led to higher perturbation of wind field when compared with the curved geometry. The curved stack presents an increase of vorticity, indicating the generation of more turbulent structures. The PIV results also confirmed that higher wind velocity at the inlet conducts to higher vorticity levels, as well as a higher number of Kelvin–Helmholtz structures. For distinct wind conditions the PIV measurements point out different patterns, indicating the northern wind direction as the most favorable condition for the exposure of dock workers to pollutants. Overall, the results showed that a ship stack with a curved end, medium length and smaller diameter has the capability to promote the behaviors in the flow that are coherent with increased pollutant dispersion