Volatile organic compounds (VOCs) and carbon monoxide are considered the main greenhouse gas pollutants from either automotive engines or stationary sources. The increased concentration of these pollutants in air severely affects human health and causes changes in earth climate and vegetation growth rates. Ethylene is one of the VOCs closely related with photocatalytic pollution when it reacts with nitrogen oxides in the presence of sun light to form ground-level ozone. It is also responsible for quick repining of fruits and vegetables. Carbon monoxide, on the other hand, is a poisonous gas mainly released by vehicle emissions, and when inhaled in high concentrations, it causes severe health problems related to the respiratory system leading to significant rates of deaths annually in Europe and North America. Globally, The World Health Organization (WHO) estimates that seven million people die yearly due to poor air quality-related reasons which urges current and future stringent regulations to control air pollution emissions. In the past four decades, several equipment modifications and processes have been studied for reducing these emissions. Among them is the phenomenon of Electrochemical Promotion of Catalysis (EPOC) which was first reported in the early 1980s. EPOC has been successfully shown to convert automotive, indoor and industrial air pollutants such as VOCs, CO and nitrogen oxides (NOx) to harmless gases. It involves reversible changes in the catalytic properties of catalysts deposited on solid electrolytes when a small electric current or potential is applied. More recently, it was demonstrated that EPOC can be thermally induced without any electrical polarization, in analogy to the well-known phenomenon of metal-support interaction, by using noble metal nanocatalysts supported on ionically conducting materials such as yttria-stabilized zirconia (YSZ). The objective of this research is to gain deeper understanding of the factors affecting metal-support interaction between the active metal and the support to enhance their catalytic activity for environmentally-important reaction systems; specifically, ethylene and carbon monoxide oxidation as well as hydrogen fuel purification by carbon monoxide methanation. First, the activity of platinum nanoparticles deposited on carbon black, which is a conventional support used in catalysis, is studied. The effect of particle size of four Pt/C nanoparticles synthesized using a modified reduction method for ethylene (C2H4) complete catalytic oxidation is investigated. These catalysts show high activity towards C2H4 oxidation which is found to be a strongly size-dependent reaction. Full conversion of 1000 ppm C2H4 is achieved over the smallest nanoparticles (1.5 nm) at 100oC while higher temperature 170oC is required to completely oxidize ethylene over the largest nanoparticle (6.3 nm). The second stage of this research compares the catalytic activity of platinum and ruthenium nanoparticles when deposited on ionic or mixed ionic conductive vs. non ionic conductive supports for CO and VOCs oxidation. The Pt and Ru nanoparticles are deposited on yttria-stabilized zirconia (8% Y2O3-stabilised ZrO2), cerium (IV) oxide (CeO2), samarium-doped ceria (SDC), gamma-alumina (γ-Al2O3), carbon black and on novel perovskite group Sm1-xCexFeO3 (x = 0, 1, 5) resulting in ≤ 1 wt. (weight) % of Pt and Ru on each support. It is found that the nanocatalysts deposited on ionic conductive or mixed ionic conductive supports outperformed the catalysts deposited on non ionic conductors due to strong metal-support interaction that greatly affects the electronic and catalytic properties of the catalysts. The enhanced catalytic activity towards CO and C2H4 oxidation reactions is shown by earlier catalytic activity and complete conversion, lower activation energies, greater turnover frequencies and higher intrinsic rates per active surface area. To further investigate the effect of ionic conductivity of the supports and the exchange of O2- (oxygen vacancy) between the support and the catalyst surface, complete oxidation of pollutants is studied in the absence of oxygen in the gas phase. For the first time, complete oxidation of CO and C2H4 in an oxygen-free environment at low temperatures (< 250oC) is achieved, which represents the main novel finding in this research. The idea of pollutant removal in the absence of oxygen is extended to a practical reaction for fuel cells application which is hydrogen fuel purification from CO impurities at temperatures < 100oC. Moreover, the effect of particle size, pollutant concentration, operating conditions and support nature in the absence of oxygen in the gas feed is studied. It is proposed that the metal nanoparticles and the solid electrolyte form local nano-galvanic cells at the vicinity of the three-phase boundary where the anodic reaction is CO or C2H4 oxidation and the cathodic reaction is the surface partial reduction of the support. A systematic catalyst reactivation process is suggested and the catalytic activity of these nano-catalysts is studied which can be further investigated for air pollution control applications such as in vehicle catalytic converters, indoor air quality units and power plant emissions.

A widely used roadway runoff best management practice (BMP) used in Florida is an ex.filtration trench. Traditionally, exfiltration trenches are constructed without any filtration media. Therefore, the potential for groundwater contamination by the roadway runoff exists. Roadway runoff contains metals and nutrient pollutants. Nitrogen and Phosphorus are the most common nutrients causing impacts to receiving waters. To reduce the impact these pollutants will have on groundwater quality, Black and Gold™ media, which mainly consists of tire crumb, is evaluated. The Black and Gold™ media was found to be a good filtration media for removal of total nitrogen and nitrate + nitrite. It was found that all of the wells had experienced total nitrogen removal. These reductions ranged from 32% to 56%. The nitrate + nitrite reduction was experienced in the four wells. These reductions ranged from 4 7% to 88% in the three wells. The ortho-phosphorous and total phosphorus concentrations did not change significantly. Also, the metals concentrations did not change significantly.During the post sampling period, the turbidity of the groundwater increased. This was experienced in three of the four wells.

No description available.

A gas-phase system to oxidize and remove the platinum and palladium from automotive catalytic converter units was studied. The effects of varying reaction temperature, time and reactant gas concentration upon yields were monitored using a colorimetric procedure based on the regent p-nitroso-N, N-dimethyl amiline. Chlorine plus carbon monoxide at 700°-900°C. displayed the most promise for commercial application.

Thesis. 1979. Ph.D.--Massachusetts Institute of Technology. Dept. of Urban Studies and Planning. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ROTCH. / Bibliography: p. 273-278. / by Gregory G.Y. Pai. / Ph.D.

One of our greatest threats to surface-water quality is polluted stormwater runoff. In this research, investigated is the use of a green roof irrigated with recycled stormwater runoff to remove pollutants from stormwater runoff and reduce the volume of stormwater runoff leaving developed areas. The green roof properties of interest are the filtration and biological processes as well as the roof's ability to hold water and increase evapotranspiration, reducing the volume of stormwater runoff from the source. Because of the above mentioned reasons the experiment consists of a water quality analysis and a water budget done on several experimental chambers modeled after the green roof on the student union building at the University of Central Florida. The green roof chambers are used to study different types of growing media, different irrigation rates, and the addition of plants and how stormwater runoff quality and quantity is affected. There are also control chambers built to model the conventional roof on the student union building. The purpose of the control is to determine the effectiveness of the different media's filtration/adsorption processes and ability to hold water, in addition to identifying the benefits of adding a green roof to both water quality and the water budget. This research showed that a specifically designed green roof stormwater treatment system with a cistern is an effective way to reduce both the volume of and mass of pollutants of stormwater runoff. The year long water budget showed that this system can reduce the volume of stormwater runoff by almost 90%. The green roof model developed within this work showed similar results for the same conditions. Design curves produced by the model have also been presented for several different geographic regions in Florida. The green roof stormwater treatment system presented within this work was effective at reducing the mass of pollutants. However, the concentration of several of the examined pollutants in the effluent of the cistern was higher or equivalent to that of a control roof. Nitrate and ammonia were two that had a lower concentration than the control roof. The use of a pollution control growing media was also examined. The results of this study show that the Black & GoldTM growing media is effective at removing both ortho-phosphorus and total phosphorus. Isotherm analysis was also preformed to quantify the adsorption potential. Despite the promise of the Black & GoldTM growing media to remove phosphorus the plants did not grow as well as in the expanded clay growing media. It is suggested that the pollution control media be used as a layer under the growing media in order to get the benefits of both media.

Master of Arts / Department of Economics / Tracy M. Turner / The report examines the extent to which the United States market for tradable pollution permits has been an efficient way to reduce sulfur dioxide emissions from coal-burning power plants. To do so, this report first provides background information on the effects of SO2 emissions on the environment in the United States. It discusses the initial attempt with the 1970 Clean Air Act to reduce these emissions and its degree of success. The details of the 1990 Amendments are then given. The economic theory behind the different methods of pollution control (quantity regulation, technology mandate, taxation, and emissions restriction through tradable permits) is explained and their efficiency regarding consumer and producer surplus is contrasted. The report then reviews published articles regarding the topic at hand. The U.S. Acid Rain Program has been found to be very efficient in its ability to reduce sulfur dioxide emissions at a low cost to the producers.

This thesis describes an investigation into the spatial species conversion profiles of a Cu-zeolite SCR under engine conditions at low exhaust gas temperatures; this was then compared with a CFD model that models the catalyst via a porous medium measuring 5 x 5 x 91 cells assuming a uniform cross-sectional flow distribution. Species conversion rates were sampled at fixed points in the axial direction. The analysis of the spatial conversion profiles is a more rigorous method in assessing the ability of a mathematical model to predict the experimental data. It can also assist in the optimisation of the catalyst size, minimising packaging requirements and manufacturing costs. The experiments were undertaken on a light-duty diesel engine at a speed of 1500rpm, and at a load of 6bar BMEP; this provided exhaust gas temeraqtures between 200 and 220°C. NO2:NOx ratios were controlled by changing the size and position of the diesel oxidation catalyst, the inlet NH3: NOx ratio was also also varied, ammonia gas was used instead of urea for the purposes of simlicity. The advantage of testing on an actual engine over lab-babed studies is that the conditions such as exhaust gas composition are more realistic. A 1D CFD model was constructed using the ‘porous medium approach’ with kinetics obtained from open literature. Results from the simulations were then compared with the experimental data for the same engine conditions. It was observed that the majority of the NOx conversion took place in the first half of the brick for all NH3: NOx ratios investigated, and that the formation of N2O via NO2 and ammonia had the same influence as the ‘fast’ SCR reaction just after the inlet, which the CFD model failed to predict for the base case analyses. The influence of the inlet ammonia on the model was also noticed to be greater than in the experiments. Simple transient analyses were also undertaken on the short SCR bricks for NO2: NOx ratios of 0.6 and 0.07, and it was observed that the response time to steady-state was noticeably higher in the experiments than in the model. Modifications made to the model, including decreasing the influence of the ‘fast’ SCR reaction, and the addition of an empirical term onto the ammonia adsorption provided a noticeably better agreement for different NH3: NOx injection ratios. The desorption kinetics in the model were also altered by increasing the strength of the bonding of the ammonia onto the adsorption sites. This improved the transient agreement between the model and the experiments, but reduced the steady-state concentrations at the exit of the brick for all NH3:NOx ratios investigated.

Introdução - Destaca a necessidade de políticas públicas e de uma gestão ambiental adequadas para a promoção do desenvolvimento sustentável, a partir da avaliação da experiência de controle da poluição em Cubatão, do início do Programa de Controle da Poluição Ambiental, em 1983, até 2005. Objetivo - Descrever os resultados alcançados em Cubatão, sob o enfoque do desenvolvimento sustentável, por meio de indicadores ambientais, econômicos, sociais e institucionais, avaliando os instrumentos utilizados e o papel desempenhado pelos atores envolvidos, bem com obter a visão desses atores sobre os fatores determinantes desses resultados. Verificar a suficiência das informações existentes para a avaliação do progresso do município na direção do desenvolvimento sustentável e a possibilidade de proposição de indicadores. Identificar a visão da coletividade sobre a gestão ambiental do pólo industrial de Cubatão desenvolvida nos anos mais recentes do período da pesquisa. Métodos - Dados secundários obtidos de fontes bibliográficas e dados primários obtidos pela aplicação de questionário a população constituída de pessoas dos diversos setores envolvidos na evolução do controle da poluição em Cubatão. Os resultados deste foram analisados quantitativamente, por cálculos percentuais, bem como qualitativamente, pela metodologia do discurso do sujeito coletivo. Resultados - Houve melhoria dos indicadores ambientais e econômicos de Cubatão, porém os sociais e institucionais não acompanharam essa evolução. O Programa de Controle da Poluição executado pela CETESB foi o instrumento mais importante utilizado, sendo fundamental a atuação desse órgão, em conjunto com a sociedade civil. Essa também foi a visão dos atores envolvidos. Não foi possível encontrar indicadores suficientes para a avaliação do desenvolvimento sustentável em Cubatão, sendo necessário propor indicadores. Segundo os participantes da pesquisa, a gestão ambiental do pólo industrial de Cubatão apresenta diversos problemas, sendo enfatizada a gestão em consonância com as exigências do desenvolvimento sustentável como o melhor caminho para o município. Conclusões - Os dados demonstram que o desenvolvimento do município não vem sendo efetuado em bases sustentáveis, sendo fundamental para tanto a atuação integrada e pró-ativa do setor governamental, empresarial e sociedade civil, bem como a existência de instrumentos adequados. As informações existentes sobre o município são insuficientes, havendo necessidade de um sistema de informações adequado. Segundo o discurso do sujeito coletivo produzido, a gestão ambiental do pólo industrial de Cubatão deve ser fundamentada na harmonização de objetivos ambientais, econômicos e sociais. / Introduction: This paper highlights the need of suitable public policies and environmental management to promote sustainable development by assessing the Cubatão Environmental Pollution Control Program experience from 1983 to 2005. Goal: To describe the results achieved in Cubatão from the sustainable development standpoint by making use of institutional, social, economic and environmental indicators, and assessing the instruments used and the role played by the actors. To investigate those actors' view of the factors which determined those results. To check whether the existing information was sufficient when assessing the municipality's progress on the path of sustainable development, and whether it was possible to propose indicators. To identify how the population views the environmental management of the Cubatão industrial cluster undertaken in the last years of the research period. Methods : Secondary data from bibliographic sources and primary data obtained by means of a questionnaire applied to people from the several sectors engaged in improving pollution controls in Cubatão. The results were analyzed quantitatively, through percentage calculation, and qualitatively, by means of the collective subject discourse methodology. Results:The environmental and economic indicators of Cubatão improved, while the social and institutional indicators did not improve at the same rate. Cetesb's Pollution Control Program was the most important instrument used, with its action being critical along with civil society's action. That view is also shared by the actors involved. It was not possible to find sufficient indicators to assess sustainable development in Cubatão, which made it crucial to propose indicators. According to those taking part in the survey, environmental management in the Cubatão industrial cluster presents several problems, which requires placing emphasis on management complying with the requirements of sustainable development as the best solution to the problems faced by the municipality. Conclusions: The data collected shows that the municipality has not been developing in a sustainable manner. In order to do so, it is imperative that civil society, government and business sectors take integrated and proactive action, and make use of suitable instruments. The data about the municipality are insufficient, which makes a suitable information system necessary. According to the resulting collective subject discourse, environmental management in the Cubatão industrial cluster must be based on harmonizing social, economic and environmental goals.

Thesis. 1978. Ph.D.--Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Vita. / Includes bibliographical references. / by Jeffrey C. Alexander. / Ph.D.