Master of Science / Department of Civil Engineering / Kyle Riding / The relationship between in-place concrete strength and permeability with concrete cylinder strength and permeability with time is of interest - especially when supplementary cementitious materials (SCMs) are used. A joint research project between The University of Kansas was undergone to quantify these relationships. The permeability of concrete is directly tied to its ability to mitigate certain failure mechanisms such as corrosion and sulfate attack. The three concrete mixtures being tested by Kansas State University (KSU) vary in cementitious content as follows: (1) 100% ordinary portland cement (OPC), (2) 25% Class F fly ash (F-ash) and 75% OPC, (3) 25% Class C fly ash (C-Ash) and 75% OPC. The mixtures were also placed in three different seasons to present differing curing environmental effects. The summer slabs were cast during July and August. The fall slabs were cast in October and November. The final set of slabs were cast in March and April. Three sets of concrete specimens (lab cured, field cured and in-situ core specimens) were tested at 28, 56, 90, 180, and 360 days for strength and permeability properties. The permeability performance tests being utilized are ASTM C1202 and ASTM C642. The results have shown very desirable permeability and strength data for the mixes using blended fly ash cements. The F-ash exhibited the best high early strength and low permeability data for the summer placement season and slower strength and permeability performance at cold weather. The C-ash performed the best overall for all seasons and had the least environmental effects. The OPC performed the worst in regards to permeability and did not reach as high long term strength.

Air pollution has adverse effects on human health. The respiratory system is the most exposed and short-term changes in air pollution levels have been associated with worsening of asthma symptoms and increased rates of heart attacks and stroke. Air pollution in cities due to traffic is the major concern, as many people are exposed. However, natural sources of air pollution such as natural dust storms and ash from volcanic eruptions can also compromise human health. Exposure to volcanic eruptions and other natural hazards can also threaten mental health. Air pollution has not been extensively studied in Iceland, in spite of the presence of several natural pollution sources and a sizeable car fleet in the capital area. The aim of this thesis was to determine if there was a measurable effect on health which could be attributed to air pollution in Iceland. This aim was pursued along two paths; time series studies using register data aimed to determine the short-term association between daily variation in air pollution and on one hand daily dispensing of anti-asthma medication or the daily number of emergency room visits and emergency admissions for cardiopulmonary causes and stroke. The other method was to investigate if exposure to the Eyjafjallajökull volcanic eruption was associated with adverse health outcomes, either at the end of the eruption, or 6 months later. In paper I time series regression was used to investigate the association between the daily number of individuals who were dispensed anti-asthma medication and levels of the air pollutants particle matter with an aerodynamic diameter less than 10 μm (PM10), nitrogen dioxide (NO2), ozone (O3), and hydrogen sulfide (H2S) during the preceding days. For the study period 2006-9, there were significant associations between the daily mean of PM10 and H2S and the sales of anti-asthma medication 3 to 5 days later. Giving the exposure as the highest daily one-hour mean gave more significant results. Air pollution negatively affected the respiratory health of asthma medication users, prompting them to refill their prescriptions before they had originally intended to. In paper II the main outcome was the number of individuals seeking help at Landspitali University Hospital emergency room for cardiopulmonary disease or stroke. Time series regression was used to identify the lag that gave the best predictive power, and models were run for data for 2003-9 pollutants PM10, NO2, and O3. O3 was significantly associated with the number of emergency hospital visits the same day and two days later in all models, and both for men, women and the elderly. Only emergency hospital visits of the elderly were associated with NO2, and there were no associations with PM10. In paper III the aim was to investigate if the health effects of PM10 were affected by the addition of volcanic ash from the 2010 eruption of Eyjafjallajökull and 2011 eruption of Grímsvötn to PM10 in the capital area. Time series regression of emergency hospital visits and PM10 before and after the Eyjafjallajökull eruption showed that the effect tended to be higher after the eruption, but the results were not significant. Analysis with a binary indicator for high levels of PM10 from volcanic ash and other sources showed that volcanic ash was associated with increased emergency hospital visits. There were no associations with high levels of PM10 from other sources. In paper IV, the health of the population exposed to the ongoing eruption of Eyjafjallajökull in 2010 was investigated thoroughly. Lung function in adults was better than in a reference group from the capital area, though many reported sensory organ irritation symptoms and symptoms of stress and mental unhealth, especially those with underlying diseases. Paper V report the results from a questionnaire study which was carried out six months after the Eyjafjallajökull eruption. The study population comprised a cohort of south Icelanders exposed to the eruption to varying degrees and a reference group from north Iceland. Respiratory and eye symptoms were much more common in south Icelanders than in the reference group, after adjusting for demographic characteristics. Mental unhealth rates had declined considerably. In the studies, we found that urban air pollution and natural particles have short-term effects on anti-asthma medication dispensing and emergency room visits and hospital admissions. Exposure to natural particles in the form of volcanic dust was associated with increased respiratory symptoms in a very exposed population. There were indications that volcanic ash particles were associated with increased emergency hospital visits in the following days. / <p>Statement of collaboration</p><p>This thesis and the work in it have been produced in collaboration between University of Iceland and Umeå University. The thesis was issued and defended at both institutions. Responsible</p>

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Dendrochronological investigations on subfossil European ash (Fraxinus excelsior L.) wood found in two bogs of Western Lithuania are presented. Radiocarbon dating has revealed that Fraxinus grew in the Middle and Late Holocene, from approximately 4700 BC to 1500 BC. It is proposed that the growth of Fraxinus at these bogs was limited by differing hydrological regimes. Rising soil water levels induced a long decline in radial growth followed by a sharp reduction (up to 51%) in ring widths before the trees died. Until now, forest history in Lithuania was mostly based on results from palynological studies. This research demonstrates the potential of using dendrochronology to extend the distribution record of Fraxinus in the Baltic region during different periods of the Holocene.

A research report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Engineering (Metallurgy and Materials Engineering), May 2016 / The solvent extraction of iron and titanium from solution generated by the two-step sulphuric acid leaching of coal fly ash by Primene JMT was investigated. The influence of hydrogen ion concentration, Primene JMT concentration, aqueous to organic volume phase ratio and temperature on the extraction of iron and titanium was determined by the use of Design of Experiments. Hydrogen ion concentration and the interaction between the aqueous to organic volume phase ratio with Primene JMT concentration had a significant effect on the extraction of iron while temperature did not. Hydrogen ion concentration and temperature did not have a significant effect on the extraction of titanium, while the interaction between Primene JMT concentration and aqueous to organic volume phase ratio had a significant effect. Extraction improvement tests showed that at a hydrogen ion concentration of 0.28M, 88% iron and 99% extraction of titanium from coal-fly ash leach solution could be achieved. Construction of a McCabe-Thiele diagram showed that a four-stage solvent extraction system with Primene JMT could reduce the iron and titanium concentration in the coal fly ash leach solutions to below 0.05g/L / GS2016

Elementos tóxicos podem provocar impacto na qualidade ambiental dos solos e representar risco à saúde humana. As cinzas leves de carvão são uma fonte de elementos tóxicos e são comumente dispostas de maneira inadequada sobre o solo nas proximidades das usinas termelétricas, onde esses elementos podem ser lixiviados pela chuva, transportados para as fontes de águas naturais e absorvidos pela fauna e flora do solo, podendo assim, entrar na cadeia alimentar humana. Neste estudo foi avaliada a mobilidade dos elementos As, Cd, Zn, Pb e Mo em colunas de solo franco arenoso com cinza de carvão da usina termelétrica de Figueira, Paraná. Para tanto, colunas de cinza de carvão, solo e solo coberto com cinza foram lixiviadas com uma solução ácida ao longo de 336 dias e as amostras de cinza, solo e percolado das colunas foram caracterizadas quanto à concentração dos elementos e propriedades físicas, químicas e mineralógicas. Os resultados obtidos mostraram que o Pb não foi lixiviado da cinza de carvão, indicando que a lixiviação de Pb da cinza de carvão não representa risco ambiental. O Cd foi o elemento mais retido pelo solo franco arenoso, seguido de As. O Mo foi lixiviado da cinza de carvão, mas não foi detectado no solo e nos percolados das colunas de solo+cinza. Nas condições de estudo, o Zn não representou risco ambiental. Observou-se também que a concentração de As no solo excedeu o valor de intervenção para área de proteção máxima estabelecido pela Companhia Ambiental do Estado de São Paulo (CETESB) e a concentração de Cd no solo excedeu o valor de qualidade de referência estabelecido pela mesma companhia ambiental. / Toxic elements can cause impact on soil environmental quality and represent risks to human life. Coal ashes, considered as a source of toxic elements, are commonly disposed inadequately on the soil surface around thermoelectric plants, from where these elements can be transported to natural water sources or to be absorbed by plants, soil fauna and flora and consequently impact on food chain. The aim of this study was to evaluate the contamination of a sandy loam soil and the mobility of As, Cd, Mo Pb and Zn from coal fly ash of Figueira Power Plant. Experiments with columns of coal fly ash, soil and soil covered with ash were carried out to simulate contamination by acid leaching during 336 days and samples of ash, soil and leachate were characterized by the determination of elements concentration and chemical, mineralogical and physical properties. Results indicate that Pb was not was not released from fly ash on study conditions, providing evidence that Pb leaching does not pose a risk to the environment. Mo was leached from fly ash, but was not detected on soil and on leachate of soil+ash columns. In study conditions, Zn did not represent environmental concern. As exceeded the intervention value for maximum protection area established by the Environmental Protection Agency of the State of São Paulo (CETESB) and Cd did not exceed the quality reference value established by the same agency.

As indústrias de papel e celulose geram enormes quantidades de cinzas de caldeira todos os anos. A disposição final dessas cinzas em aterros costumava ser prática comum, porém a sua utilização em solos florestais e agrícolas merece consideração devido ao seu potencial de corrigir a acidez e de fertilizar os solos, minimizando assim a pressão sobre sua forma de descarte no ambiente. No entanto, o uso desse resíduo pode afetar diretamente a dinâmica de pesticidas no solo, além de adicionar metais pesados. Desta forma, o presente trabalho avaliou o efeito de três cinzas de biomassa florestal (C-1, C-11 e C-27) na fertilidade e na sorção do herbicida imazetapir em três solos com atributos físico-químicos distintos (RQd, LVd e LVAd). Além das três cinzas, calcário e o controle compuseram os tratamentos, os quais foram incubados por três meses. Posteriormente, estudos de sorção do herbicida imazetapir foram realizados nos diferentes tratamentos. As cinzas C-11 e C-27 aumentarem o valor do pH dos solos e os teores de macroelementos, mas reduziram os teores de microelementos catiônicos. A C-1 mostrou ser boa fonte de K para os solos. Nenhuma cinza mostrou-se limitante quanto ao teor de metais pesados. De forma geral, o imazetapir apresentou baixo potencial de sorção nos solos e seus respectivos tratamentos (Kd < 1,8 L kg-1). A C-11 e a C-27 reduziram enquanto que a C-1 aumentou o potencial de sorção do imazetapir nos solos, o que foi devido às alterações nos valores de pH do solo. A sorção foi ligeiramente maior no solo com maiores teores de argila e carbono orgânico (LVd), enquanto a dessorção foi maior no solo de teores intermediários (LVAd). Houve histerese em todos os solos, sugerindo irreversibilidade de parte do herbicida sorvido. / The pulp and paper industries generate huge amounts of wood ash every year. The ashes disposals in landfills used to be a common practice, but their use in agricultural and forest soils deserves special attention due to their potential to neutralize acidity and to fertilize soils, thus decreasing pressure about their environmental disposal. However, the use of this residue may directly impact the dynamic of pesticides as well as add heavy metals to the soils. Therefore, this study evaluated the effects of three wood ashes (C-1 , C-11, and C-27 ) in the fertility and sorption of imazethapyr in three soils (RQd, LVd, LVAd), with contrasting physical-chemical attributes. Besides the ashes, lime and control treatments were added, all of them incubated for three months. Afterwards, batch sorption isotherms for imazethapyr were performed for all treatments. The C-11 and C-27 enhanced soil-pH and macroelement contents, but decreased cationic microelement contents. The C-1 was a good source of K to the soils. There is little risk of contamination by heavy metals. Overall, imazethapyr sorption was low in all soils and their respective treatments (Kd < 1,8 L kg-1). The C-11 and the C-27 decreased whereas C-1 enhanced sorption of imazethapyr to the soils, most likely due to changes in soil-pH. Sorption was slightly higher in the soil with higher clay and organic carbon contents (LVd) whereas desorption was higher in the soil with intermediate values (LVAd). There was hysteresis, suggesting irreversibility during sorption/desorption processes.

A cinza pesada é um sub-produto gerado do processo da queima do carvão mineral pulverizado nas caldeiras das termelétricas para a produção de vapor aquecido que atuará na geração de energia elétrica. Não há um destino adequado para esse tipo de cinza, sendo que o volume gerado diariamente é depositado em bacias de sedimentação, causando, dessa forma, problemas ambientais. Principalmente nos Estados Unidos, muitas pesquisas têm evidenciado o sucesso do emprego deste resíduo na construção de rodovias. Contudo, no Brasil as pesquisas sobre cinza pesada estão mais voltadas para a área de edificações. Deste modo, a proposta da pesquisa foi investigar os efeitos da cinza pesada quando incorporada a solos, através de ensaios laboratoriais, visando o aproveitamento deste resíduo na construção de bases e sub-bases de pavimentos. Também foi avaliado o efeito da adição de cal às misturas solo-cinza. Os ensaios utilizados na etapa experimental foram os de mini-CBR, resistência à compressão simples e resistência à tração por compressão diametral. Complementarmente, realizaram-se ensaios de CBR e de resistência à compressão simples na condição imersa. Os resultados mostraram que as adições de cinza pesada aos solos não melhoram as propriedades mecânicas das misturas compactadas. Entretanto, a adição de 3% de cal às misturas de solo-cinza proporciona a melhora significativa no comportamento mecânico das misturas, oferecendo uma solução para aproveitamento da cinza pesada na construção rodoviária. / Bottom ash is a by-product from the burning of mineral coal. It is utilized as fuel in thermal power stations in order to produce electrical energy. The bottom ashes are deposited in the lagoons and are harmful to the environment. In the United States, several researches have indicated successful uses of this waste in the construction of roadways. However, in Brazil the researches have been accomplished to use the bottom ashes in the civil construction. Thus, the purpose of the present research was to investigate the results of the bottom ash additions to soil in order to utilization in bases and sub-bases of pavements. Afterward, the effects of lime additions to soil-bottom ash mixtures were evaluates. The tests employded were mini-CBR, unconfined compressive strength and indirect tensile strength. California bearing ratio and immersion unconfined compressive strength were accomplish such supplementary tests. The results indicated that bottom ash additions to soils does not improve the mechanical properties of the compacted mixtures. However, the addition of the 3% of the lime to soil-bottom ash mixtures provided better mechanical performance, offering a feasible solution for the use of this waste in road construction.

Geopolymer concrete (GC) is a sustainable construction material and a great alternative to regular concrete. GC is a zero-cement material made from a combination of aluminate, silicate and an activator to produce a binder-like substance. This investigation focused on the effects of wet and dry cycles on the strength and durability of fly ash-based recycled aggregate geopolymer concrete (RAGC). The wet-dry cycles were performed approximately according to ASTM D559 standards. RAGC specimens with nearly 70% recycled materials (recycled aggregate and fly ash) achieved a compressive strength of approximately 3600 psi, after 7 days of heat curing at 60ºC. Although the recycled aggregate is prone to high water absorption, the compressive strength decreased by only 4% after exposure to 21 wet-dry cycles, compared to control specimens that were not exposed to the same conditions. Accordingly, the RAGC material developed in this study can be considered as a promising environmentally friendly alternative to cement-based regular concrete. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection

A cinza da casca do arroz (CCA) é um resíduo rico em sílica amorfa. Um método simples e de baixo consumo energético para extração desta sílica foi pesquisado, obtendo-se um material com baixo teor de impurezas e alta reatividade, adequado para a síntese de zeólitas e wolastonita (CaSiO3). As zeólitas sintéticas, que não possuem estruturas similares na natureza, são cada vez mais valorizadas no mercado devido a pureza e eficiência em aplicações específicas nas áreas de troca iônica, peneira molecular e catálise. A wolastonita com elevado grau de pureza tem várias aplicações na indústria e agricultura. O mineral wolastonita pode ser formado de várias maneiras na natureza. Em geral é aceito que existem dois processos de formação; os quais envolvem o metamorfismo (calor e pressão) do calcário. Neste trabalho, foi desenvolvido um novo processo para a síntese das zeólitas e da wolastonita, ambas a partir da sílica coloidal da CCA; tendo como objetivo um processo de um menor custo energético, menor número de etapas e menor consumo de reagentes. Foram sintetizadas neste trabalho as zeólitas: A, usada em detergentes, e a ZSM-5, empregada na indústria petroquímica, devido a sua alta seletividade em reações catalíticas e grande estabilidade térmica e resistência aos ácidos. A primeira etapa na síntese da wolastonita foi estudada com o objetivo da formação do hidrossilicato de cálcio (CSH). Contudo, onze hidrossilicatos de cálcio diferentes ocorrem no sistema Ca(OH)2-SiO2-H2O que em uma segunda etapa passam por um tratamento térmico para dar formação a fase wolastonita. / Rice hull ash (RHA) is a industry scrap rich in amorphous silica. A simple and low-energy cost method for the extraction of this silica was researched. A low level of impurity and high reactivity material was produced, which is appropriate for the synthesis of zeolites and wolastonite (CaSiO3). The synthetic zeolites, has not similar structures in nature, and they have been more and more valued in the market due to their purity and efficiency in specific applications like ion exchange, molecular sieve and catalysis areas. High purity wolastonite has many applications in manufacturing and agriculture. The mineral wolastonite can be formed in nature in different ways; it is generally accepted two forming processes, both encompassing limestone metamorphism (heat and pressure). In this work, a new process for the synthesis of zeolites and wolastonite from RHA colloidal silica was developed. Moreover, the process is aimed at lower energy costs, fewer stages and fewer reactants consume. In this work, zeolite A used in detergent and zeolite ZSM-5, employed in the petrochemical industry due to its high selectivity in catalytic reactions and its high thermo and acid stability, were synthesized. The first step of the wolastonite synthesis was studied, with the purpose of obtaining calcium hydrosilicate. Eleven different hydrosilicates occur in the system Ca(OH)2-SiO2-H2O, in the second step, it was annealed to form the wolastonite phase.