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Любека, Андрій Миколайович. "Гранулювання багатокомпонентних рідких систем в псевдозрідженому шарі." Thesis, КПІ ім. Ігоря Сікорського, 2021. https://ela.kpi.ua/handle/123456789/39467.
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Дисертаційна робота спрямована на вирішення важливої науково-технічної
задачі – підвищення ефективності процесу одержання інноваційних гранульованих
органо-мінеральних добрив необхідних для впровадження принципів раціонального
землекористування.The dissertation is aimed at solving an important scientific and technical problem - increasing the efficiency of the process of obtaining innovative granular organo-mineral fertilizers necessary for the implementation of the principles of rational land use. The dissertation is devoted to increase efficiency of process granulation in a fluidized bed of multicomponent heterogeneous liquid systems containing in equal quantities nutrients of an organic and mineral origin from obtaining complex granular humic-organomineral fertilizers with specified properties.
Диссертационная работа направлена на решение важной научно-технической задачи - повышение эффективности процесса получения инновационных гранулированных органо-минеральных удобрений необходимых для внедрения принципов рационального землепользования.
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Zaidi, Syed Azhar Mehdi. "The control of combustion and pollutant emissions of pulverised fuel flames through the implementation of fuzzy logic based embedded reasoning." Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.398941.
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Handley-Sidhu, Stephanie. "Biogeochemical controls on the corrosion and fate of depleted uranium." Thesis, University of Plymouth, 2008. http://hdl.handle.net/10026.1/500.
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Depleted uranium (DU) is a by-product of the nuclear fuel industry and is used in anti-tank penetrators due to its high density, self-sharpening and pyrophoric properties. Military activities have left a legacy of DU waste in terrestrial and marine environments and presently there are no clean up procedures in place. In order to understand the fate of this DU, long term (500 days) microcosm experiments simulating key environments have been carried out for the first time to investigate the mechanisms and rates of DU corrosion as a function of the biogeochemical and environmental conditions.
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Leskinen, Anumaija. "Investigations of the use of natural organic matter as a remediation material." Thesis, Loughborough University, 2011. https://dspace.lboro.ac.uk/2134/8471.
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Industrial activities and accidental releases often introduce a large amount of inorganic and organic contaminants to the environment. Humic substances interact strongly with metals and organic pollutants. In this study, this property was exploited in order to establish new remediation materials in two environmental applications and in one pharmaceutical application. The two remediation materials under investigation were sludge and sediment, ST sludge and CE sludge, respectively. The first application aimed at investigating the use of the remediation materials to remove arsenic, iron, and uranium from the industrial effluents. The main results were the release of iron from ST sludge inhibited its usage as remediation material whereas CE sludge showed excellent performance. The extractions were both rapid and efficient. The second application studied the extraction of organic contaminants. The objective of this study was to find a new remediation material for removal of organic contaminants. The remediation materials showed similar and excellent performance on extraction of chlorinated anilines, phenols and benzenes. The third application investigated the extraction of iodine species from urine. It aimed at determining whether the radioactive iodine can be extracted from the urine and thereby concentrated into a smaller volume of solid. Even though the extraction percentages from urine were not as promising as from deionised water and synthetic urine, scientific interest was raised and further investigations on the effect of the composition of urine and solubility of sludges for the extraction of iodine species were recommended. The outcome of the presented study was interesting both scientifically and economically. The promising extraction results for arsenic, iron and uranium indicate that the CE sludge is ready to be tested in a field study. The extraction of organic compounds by both remediation materials was also promising. However, further studies on permeability and solubility were recommended.
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Elliott, Claire. "Novel electrochemical systems for asymmetric oxidation." Thesis, Loughborough University, 2011. https://dspace.lboro.ac.uk/2134/8491.
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Organic reactions, which can be carried out in water and in the absence of heavy metals, are becoming more important today due to concerns over safety and environmental impact. Thus if an oxidation reaction can be carried out, where the oxidant is generated in-situ using electrolysis, then this is advantageous over existing systems that use strong or large volumes of stoichiometric oxidant and solvent, that cannot be recycled. In this thesis a wide variety of conditions and methods for producing enantiomerically enriched epoxides and sulfoxides have been reported using both electrochemically generated percarbonate and hypochlorite. It has been possible to carry out a range of oxidation reactions both as a one-pot reaction and with the oxidant generated in a batch process. Carrying out sulfoxidation reactions as a batch process with a carbonate solution it is possible to obtain ees of 20%. Using our in-situ generation of oxidant, as a one-pot electrochemical reaction, has provided a wide range of sulfoxides in good to excellent yield, with the application of this system to the oxidation of alkenes using a chiral iminium salt resulting in 100% conversion, with up to 44% ee.
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Elekwachi, Chijioke Obioma. "Bioinformatics resources to support bioremediation research." Thesis, University of Nottingham, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.595818.
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Contamination of ecosystems by xenobiotic substances has led to significant negative impacts on the ecologies and on the health and economic livelihood of the human populations in affected environments. Bioremediation, particularly microbial bioremediation, has proven to be a safe, low-cost and environmentally friendly method for remediation of such areas. However, a lack of complete understanding of the metabolic, enzymatic and cellular processes involved has made it difficult to model and predict outcomes of field processes. The ability of researchers to make critical decisions capable of influencing the direction and outcomes of these processes is also hampered. This study outlines the results of a survey and describes the electronic Microbial BioRemediation (eMBR) web portal, designed to improve collaboration in the bioremediation research community. It describes the structure, algorithms and output of three bioinformatics resources developed and deployed via the portal. eMBRLitMine addresses the problem of identifying which microorganisms would be suitable for remediating sites contaminated by named compounds. It combines named-entity recognition algorithms, a mySQL database, graph rendering technologies and Perl scripts to create, from the vast information available within published literature, a statistical co-occurrence matrix which it uses to infer possible associations between microorganisms and particular contaminants. This provides valuable insights into possible bacteria/contaminant relationships and highlights bacterial species that could be used in remediation of specified contaminants. eMBRCatalogue is a moderated and searchable database cataloguing bioremediation case studies. Implemented as an eXtensible Markup Language (XML) database employing a user-generated-content framework, it provides background knowledge necessary for planning and execution of bioremediation activities. Developed following the construction of a comprehensive metabolic biodegradation network, eMBRHelper enables the delineation of possible biodegradation pathways for named contaminants. By integrating relevant chemical, enzymatic and genomics information, it attempts to model the interplay between contaminants, enzymes, microorganisms and degradation pathway, enabling researchers to make informed decisions for improved outcomes, particularly for remediation exercises involving bioaugmentation. The study also analysed usage of the portal and resources, made recommendations for future developments and highlights avenues for further informatics support for the bioremediation research sector.
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Olimah, Joseph Abah. "Mobility and bioavailability of arsenic in ochre amended soils." Thesis, University of Reading, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.632999.
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Contamination of soil with arsenic (As) is a global environmental concern because As is toxic and carcinogenic. Ochre, a waste generated from mine water processing, has great potential for the remediation of As contaminated soils due to its high iron (Fe) oxyhydroxides content. Iron oxyhydroxides have large reactive surface areas for As adsorption. This research investigated the potential of ochre to adsorb As in solution and in contaminated soils and also assessed the possibility of using ochre to eliminate As exposure transport pathways (leaching to groundwater, plant uptake and soil ingestion).
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Mariner, Richard Clive. "Development and characterisation of a novel biological system for removing managanese form contaminated waters." Thesis, Bangor University, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.488875.
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Cai, Zhuo. "Characterisation of electrochemically activated solutions for use in environmental remediation." Thesis, University of the West of England, Bristol, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.418216.
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This thesis aims to investigate the production of electrochemically activated solution via electrolysis of diluted NaCI solution using a commercial electrochemical system (STEL device), characterise the activated solution, and evaluate the potential application of this solution in the treatment of water containing organic compounds. The research shows that the electrolytic cell in the STEL device consists of a titanium based metal oxide (Ir02, Sn02, and Ti02) coated anode, a tubular titanium cathode, and a tubular ceramic diaphragm that separates the anode and cathode. A model electrolytic cell using STEL anode material was designed and constructed for investigating reaction mechanisms occurring at the electrode and identifying the oxidising species generated at the anode during the electrolysis of NaCI solution. Experimental results show that chlorine and oxygen were two main oxidants contained in the anolyte, indicating that the generation of chlorine and oxygen are involved in the electrode reactions. The evolutions of chlorine and oxygen were found to be achieved via the formation of a series of adsorbed intermediates such as OHad, Oad on the anode surface during electrolysis. Evidences for the occurrence of the intermediates were obtained by several electrochemical observations. It is suggested that the evolution reaction of chlorine involves a mechanism in which an intermediate of OClad is formed instead of Clad. The adsorbed intermediates may also be released from the anode surface to form chlorine free radicals and hydroxyl radicals when the electrolysis is carried out at higher potentials. This was investigated using the electro-oxidation of salicylic acid (SA). It was found that in a buffer solution containing chloride ions, the oxidation processes of SA were dependent on the potential applied on the anode. At + l.5V, the reaction product was 2,4,6-trichlorophenol, indicating that chlorine free radicals were generated. At +2.5V, the obtained products included 2,5-dichloro-l,4-benzoquinone, indicating that a hydroxyl group is introduced to the benzene ring of SA. These results suggest chlorine free radicals were generated at + l.5 V while hydroxyl radicals were generated at +2.5V. The operating conditions of the STEL device were optimised with respect to the redox potential, pH, and chlorine concentration of the generated ECAS. Anolyte produced from the STEL system, using a 100/0 NaCI solution under optimised electrolysis conditions, is an acidic solution (PH 2.2) containing a mixture of oxidants with a redox potential of 1190 m V and an available free chlorine concentration of 280 mgIL. The catholyte solution is a reductive basic solution with a pH of 12.6 and a redox potential of -950m V. The anolyte solution can maintain the oxidation ability up to 6 days when it is stored in an air tight container. However, it will lose its oxidation ability in 30 min if is purged by nitrogen or in 60 min if is stirred in the atmosphere. The anolyte solution can degrade trace amounts of aromatic compounds in aqueous solution. The degradation products are dependent on the concentration and chemical nature of the reagents. Usually, 10-4M SA can be converted to ring opened compounds, while 10·3M SA can only be converted to quinonic compounds. A subsequent dechlorination step is required when using anolyte for treating aqueous solution containing organic compounds as the by products include chlorinated compounds.
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Obuekwe, Ifeyinwa S. "Biodegradation of polycyclic aromatic hydrocarbons in soils co-contaminated with metals." Thesis, Lancaster University, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.656325.
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Mixtures of polycyclic aromatic hydrocarbons (PARs) and heavy metals are of major concern in contaminated soil. The aim of this project was to investigate the impact of heavy metals and PAHs on microbial activity, concentrating on the mineralisation of PAHs and partitioning of phenanthrene in the presence of metals. Naphthalene and phenanthrene were used as model PAHs and Zn, Cu, Al and Fe were used as model heavy metals. 14C_ Naphthlene and 14C-phenanthrene mineralisation were followed in soil with varying concentrations of Zn, Cu, Al and Fe; a sequential aqueous\solvent extraction scheme was also used to assess the partitioning of phenanthrene in the presence of these metals. Zn and Cu (50 and 100 mg/kg) stimulated (p < 0.05) 14C-naphthalene mineralisation, but had no impact on 14C-phenanthrene mineralisation. Zn (500 and 1000 mg/kg) had no impact on 14C-phenanthrene mineralisation (p > 0.05), but Cu (500 and 1000 mg/kg) significantly reduced (p < 0.05) phenanthrene catabolism, particularly in aged Cu. Zn and Cu mixtures (500 and 1000 mg/kg) inhibited 14C-phenanthrene catabolism. 14C-Glucose mineralisation (maximum rates) and incorporation into the microbial biomass were significantly reduced at higher Zn and Cu concentrations (500 and 1000 mg/kg). Al and Fe (50 and 100 mg/kg) stimulated (p < 0.05) both 14C-naphthalene and phenanthrene mineralisation, however, Al (500 mg/kg) significantly reduced (p < 0.05) mineralisation of both PAHs. Fe (500 mg/kg) stimulated both 14C-naphthalene and phenanthrene mineralisation. Cu and Al (500 mg/kg) significantly increased (p < 0.05) 14C-phenanthrene extractable CaCh and HPCD fractions, this could be because of their great affinity for the organic and mineral soil components. The impact of metals on the biodegradation of PAHs depends on the type and concentrations of the metals, as well as the incubation time. Studies on metal-P AH impact in soil facilitates the assessment of risk, hazard and bioremediation potential at sites contaminated with both contaminants.
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Okere, Uchechukwu Victor. "Biodegradation of polycyclic aromatic hydrocarbons in "pristine " soils from different environmental systems." Thesis, Lancaster University, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.656326.
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Global soils have the capacity to act as a sink for polycyclic aromatic hydrocarbons (PAHs) and subsequently as a secondary source making soil/PAH interactions important to environmental PAH levels. A number of physical, chemical and biological processes determine P AH fate in soil but microbial degradation is the most important. Biodegradation depends on bioavailability, soil organic matter, water and nutrient content, temperature and previous exposure to PAHs. Globally, environments differ and soils from different geographic regions differ in their properties and PAH concentrations. While the importance of diffuse P AH contamination of soils is widely acknowledged in literature, most studies on P AH biodegradation in soils have been conducted on soils contaminated from a P AH point source. The aims of this project were to investigate the indigenous biodegradation of PAHs in pristine soils from different geographic locations as well as what environmental factors are most significant in the development of PAH biodegradation potential in pristine soils. Pristine soils used include soils from Antarctica, Norway, UK and Tibet. Levels of PAHs in all the soils were low and properties like soil organic matter, nutrients and water content were different. P AH degrading bacteria were present in all the soils studied irrespective of low PAH concentrations. Temperature was found to affect both the rates and extents of P AH degradation in the Antarctic soils. Results also suggest that the effect of temperature on adaptation of indigenous microbes to PAH degradation might be more important than that of lack of exposure. Further works suggested include the identification of individual P AH -degrading bacteria in these background soils and investigating the effect of increasing soil P AH-contact time in low organic matter background Antarctic soils.
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Alhassan, Mohammed. "Biochar for combined carbon sequestration and bio oil generation from co-pyrolysis of biomass with bone matter." Thesis, University of Nottingham, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.659209.
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Biochar from biomass pyrolysis offers a geotechnical solution to the major global issues of climate change, soil degradation and food shortage . The focus of this study is to generate stable and nitrogen enriched biochars and high quality bio oils from co -pyrolysis of biomass with bone matter at low temperatures. The biochar can act as a fertilizer because of its mineral contents while at the same time promotes carbon sequestration when used as soil amender. By improving the use of biochar, it may be possible to also utilize the bio oil for renewable generation. Currently, the biochar production process suffers from the draw backs such as the use of high temperature of up to 500°C, low biochar yield and poor bio oil quality which as rendered its applications beyond solid fuels. This work has focused on the co-pyrolysis of bone matter (BM) with pistachio (PS), Pine wood (PW), and Wheat straw (WS) at low temperatures to produce carbon and nitrogen rich biochar and improved bio oil. A prototype tubular reactor was designed and commission for pyrolysis of BM in the temperature range of 150°C to 600°C and mixing BM from 2.5wt% to 20wt%. The analysis of the biochar product showed that the addition of BM to the biomass increased their biochar yields with up to 10wt% BM addition. This was linked to the ability of the BM to interact with the biomass and retain condensable compounds at temperatures between 300°C and 350°C. Addition of BM above 10wt% was found to reduce the overall biochar yield from the biomass and promote gasification. At 10wt% bone addition, the carbon and nitrogen contents of the biochars were both increased compared with the biomass on its own, while the oxygen content decreased.
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Gharebaghi, Maryam. "Numerical and experimental investigation of the oxy-coal combustion in carbon capture technologies." Thesis, University of Leeds, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.659033.
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The coal-fired power generation industry is responsible for a large portion of the CO2 emission to the atmosphere. In many countries, Carbon Capture and Storage (CCS) is suggested as a long-term solution for CO2 mitigation. Oxy-coal combustion, one of the CO2 capture processes in the CCS, with Recycled Flue Gas (RFG) can be applied to the conventional coal combustion plants with modifications. However, based on the · preliminary investigations and laboratory-scale data, technical challenges have to be undertaken before oxy-coal combustion reaches the demonstration phase. In this thesis, prediction of the performance of an oxy-coal Combustion Test Facility (CTF) with RFG, and defining the challenges, are the main objectives. Technical challenges of the oxy-coal combustion are addressed, combustion physical submodels are discussed and challenges regarding modelling of the oxy-coal combustion are addressed. State-of-the-art char combustion models, along with a comprehensive set of microscopic studies (SEM, EOX and XRO) of the fly ash from air- and oxy-coal combustion tests, are discussed. Following that, a requirement for revision of the standard char burnout models for application to oxy-coal combustion is presented. An updated gas-phase mercury chlorination mechanism is presented and validated with the unbiased experimental data. In parallel, the solid-phase mercury retention and oxidation processes on the fly ash are investigated. Furthermore, an empirical correlation for the prediction of mercury speciation in the NOx removal unit is suggested. Following the development of a combined homogeneous-heterogeneous mechanism, recommendations regarding a global model for predicting the mercury transformation through the power plant are addressed. The 1 MWth CTF of interest is modelled using advanced numerical simulation (CFO) methods. The geometry set up, the boundary conditions and the approach for grid independency and optimization are discussed. Two variations of turbulence modelling techniques for simulation of air- and oxy-coal combustion have been used to assess the CFO modelling predictions. Finally a techno-economic analysis of the oxy-coal combustion process is given in detail. This includes a comparison of the thermodynamics and the costs of typical air-coal, post-combustion and oxy-coal combustion processes in the UK and China.
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Abogrean, Elhadi. "Physico-chemical parameters of wet deposition in Cardiff." Thesis, Cardiff Metropolitan University, 2008. http://hdl.handle.net/10369/868.
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The issue of acid deposition and associated environmental problems has received special attention during recent decades and has been the subject of extensive research in a number of countries. However, there are no recent studies on acid deposition in Cardiff. Weekly rainfall samples were obtained from two urban areas in Cardiff from February 2006 to July 2007 and analysed for pH, electrical conductivity and major ions; SO42−, NO3−, Cl−, Ca2+, Na+, Mg2+, K+ and Pb2+. The chemical composition of precipitation was analysed in conjunction with meteorological variables to evaluate temporal and seasonal variations. Annual wet deposition was estimated, and enrichment factors determined. The pH of individual precipitations fluctuated excessively with a wide range from 4.9 to 6.6 indicating high variability in the acid sources and in neutralisation processes. Correlations between calcium and sulphate imply that CaSO4 may merge with the rainfall and neutralise the acidity. The volume-weighted mean concentrations of NO3− and non-sea salt SO42− were 24.1 and 31.4 μeq l−1, respectively. With the exception of the sea salt ions, no distinct spatial variations in ion composition were observed. Enrichment factors were calculated for most ions and higher correlation coefficients were obtained among most of the ions. Sea-derived material (Na+, Mg2+ and Cl−) showed pronounced cycles in concentration with maxima in autumn/winter. The Cl- (102 kg ha-1 yr-1) and Na+ (66 kg ha-1 yr-1) showed the highest wet deposition flux compared to the other ions. Anthropogenic and crustal sources made a significant contribution to both the acidification and neutralisation of precipitation in Cardiff. In all rain samples SO4-2 concentration exceeded NO3- concentration. Statistical analysis showed no significant differences in the physico-chemical parameters of the rainfall samples between the sites when tested at p<0.05. However, the ionic concentrations of wet precipitation depicted significant seasonal differences except for rainfall volume, K+, NO3- and SO4-2
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Whittleston, Robert Andrew. "Bioremediation of chromate in alkaline sediment-water systems." Thesis, University of Leeds, 2011. http://etheses.whiterose.ac.uk/2024/.
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The poorly controlled disposal of chromium ore processing residue (COPR) is a globally widespread problem due to its potential to form chromium contaminated hyperalkaline (pH > 12) leachates. These highly oxidising leachates typically contain chromium in the Cr(VI) oxidation state as its chromate anion (CrO42-). This anion is highly mobile, toxic, carcinogenic, and exhibits a high degree of bioavailability. Under reducing conditions chromium exists in the non-toxic and poorly soluble Cr(III) oxidation state. Thus, the reduction of Cr(VI) to Cr(III) is often the goal of remediative strategies. In anaerobic subsurface environments where reducing conditions are established by the indigenous microbial population, chromium reduction can occur naturally. The microbial transformation of Cr(VI) to Cr(III) can be both a result of its direct use in microbial metabolism, or through its indirect reaction with microbially produced reduced species, e.g. Fe(II). This study has used a multidisciplinary approach to investigate the biogeochemical influences on the fate and stability of Cr(VI) leaching from a site of COPR in the north of England. Reducing sediments encountered directly beneath the COPR waste were found contain elevated concentrations of chromium. These sediments were shown to be able to remove aqueous Cr(VI) from solution when incubated with contaminated site groundwater in microcosm incubation experiments. This removal is likely a result of the abiotic reduction by soil associated microbially produced Fe(II), followed by precipitation as insoluble Cr(III) hydroxides. X-ray absorption spectroscopy (XAS) and electron microscopy confirms the association of chromium as Cr(III) with iron in these soils, hosted as a mixed Cr(III)-Fe(III) oxyhydroxide phase. Upon air oxidation, only minor amounts of chromium was remobilised from these sediments as Cr(VI). A diverse population of alkaliphilic microorganisms are indigenous to this horizon, capable of successful metabolism despite elevated pH values. This population was found to contain a consortium of microorganisms capable of iron reduction when incubated at pH 9 to 9.5. Microbial community analysis found taxonomic similarity to several known metal reducing alkaliphiles from the phylum Firmicutes. These results suggest that the novel action of iron reducing alkaliphiles indigenous to reducing sediments beneath COPR sites may provide zones of natural chromium attenuation via microbially mediated mechanisms of Cr(VI) transformation.
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Smith, Peter. "Management and sustainability issues relating to the phytoremediation of landfill leachate." Thesis, Bangor University, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.664483.
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Land-based systems for the remediation of landfill leachate have the potential to provide a low-cost, low-tech alternative for dealing with the consequences of the long-term generation of polluted water from a body of municipal solid waste. However, assessing the sustainability of these systems is hampered by limited long-term monitoring under controlled and field conditions and its impact upon soil chemical quality. Despite these limitations, landfill leachate has been successfully irrigated to a range of vegetation communities. Three vegetation-based trials and a computer-modelling exercise were conducted in an attempt to assess the sustainable management for dealing with leachate from the Penhesgyn landfill site in north Wales.
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Mohd, Din Shamzani Affendy Bin. "Collection and physical characterization of airborne particulates." Thesis, Cardiff University, 2007. http://orca.cf.ac.uk/56141/.
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Airborne particulates are one of the most complex air pollutants and considerable concern surrounds their environmental impact especially with regards to human health. An investigation of the efficiency of various total inhalable and respirable dust samplers has been conducted to identify the most convenient way of collecting dust particles to examine their physical characteristics. The efficiency of a variety of dust samplers were investigated using limestone dust clouds generated inside an environmental dust chamber. Various sampling periods were employed to establish dust concentrations in the environmental dust chamber. The experimental dust cloud was found to contain on average 55.74 % of respirable dust as defined by different instruments while a consistent dust concentration of approx 200 mg/m3 was repeatedly produced. The methods for collecting and estimating airborne asbestos fibre concentrations were studied and found to be extremely limited. Standard optical techniques grossly underestimated both airborne fibre concentrations and respirable dimensions of fibres. The size and dimensions of respirable asbestos fibres are defined by their ability to gain access to the lungs and there is no instrument or technique available at present, which will allow collection and estimation of respirable fibrous dust clouds. A comparison of coal dust particles with similar particles retained in the lungs has shown a difference from the predicted respirable fractions as proposed by the British Medical Research Council (BMRC) and other conventions. Respirable dust sampling instruments may therefore be under sampling larger particles. The difficulty in estimating the characteristics of airborne particulate material has been demonstrated by illustrating urban particulate collection and analysis. The extremely large differences in terms of physical size, and aerodynamic properties of dust particles formed by different materials have been demonstrated.
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Cairns, Justin. "Emissions abatement technology, fuels and low emissions vehicles : win-win for air quality and climate change." Thesis, University of Newcastle upon Tyne, 2013. http://hdl.handle.net/10443/2120.
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The impact of a change in emissions abatement technology, fuel or vehicle on carbon dioxide (CO) 2 and toxic air pollutant emissions derived from road transport was investigated. Road transport emissions were calculated and non-mobile source emissions rates were compiled for the base year 2005 for the City of Leicester, which was the case study for the research. Factor and cluster analysis were applied so that roads could be classified into groups, allowing diurnal traffic profiles to be assigned to roads with similar attributes prior to air quality modelling and to enable the characteristics of typical roads in Leicester to be identified. Five road classifications were developed. The emissions inventory compiled along with meteorological data, background pollutant concentration values and the five diurnal traffic profiles were input into an air quality model. The BOOT evaluation framework (Chang and Hanna 2005) was used to statistically evaluate the performance of the air quality model through comparisons of predicted and observed pollutant concentrations. The model was found to significantly over-predict and under-predict concentrations of nitrogen dioxide (NO) and particles with a diameter of less than ten microns (PM) at seven and five 210 monitoring locations across Leicester. A discussion of the sources of error in prediction was presented. The base-case was edited to reflect a change in emissions abatement technology, fuel or vehicle and emissions were recalculated. In addition, a vehicle kilometres travelled (VKT) restriction was imposed on the vehicle fleet that did not allow any increase in VKT from the base year. The changes to the base-case were made in increments of 5% until 100% was reached. Regression analysis was used to create 13 models that allowed the impact of the road transport strategies on CO and pollutant 2 emissions to be explored. A reduction in both CO and toxic air pollutant emissions (‘win-win’) was found when the penetration 2 of zero emissions vehicles (ZEVs) and plug-in hybrid electric vehicles (PHEVs) to the car fleet was modelled. Overall, the highest reduction in toxic pollutant and CO emissions were found for ZEVs, 2 which represent electric vehicles (EVs) under current legislation. A 53% (or greater) penetration of ZEVs to the car fleet was the only strategy for which a 50% reduction in CO for a 1990 base was 2 found. Therefore, this indicates that substantial and arguably radical changes are required if air quality and climate change limit values and targets to be achieved. A win-win for air quality and climate change was found when new emissions abatement technology was introduced into the car fleet. However, greater pollutantemissions reductions were observed with the introduction of new emissions abatement technology to light goods vehicle (LGV) and heavy goods vehicle (HGV) stocks. These strategies were found to have a negligible impact on CO 2 emissions. Consequently a trade-off was found where a ‘win-win’ was achieved through changes to the car fleet but at the cost of higher pollutant emissions reductions from other strategies. The introduction of new emissions abatement technology to the bus fleet on roads predominantly on key traffic corridors within Leicester’s air quality management area (AQMA) resulted in substantial air quality benefits. The same strategy did not result in a reduction in CO emissions. However, in the 2 context of an overall sustainable transport strategy the benefits of increasing bus patronage, which in turn may reduce the number of single occupancy vehicles on the road, is likely to have a more than compensatory effect. Substantial pollutant emissions reductions were found as a result of the introduction of new emissions abatement technology into the HGV and LGV fleets. However, these strategies were found to have negligible CO emissions reductions and therefore did not provide a win-win for air quality and climate change. Similarly, a win-win from the introduction of LPG to the car fleet was not found. Therefore, the uptake of LPG or investment in the introduction of new emissions abatement technology to the LGV or HGV fleets should only be considered as a part of a sustainable policy package that comprises other measures, such as logistics optimisation or a reduction in VKT. The findings of this research were used to inform a set of policy actions for Leicester City Council.
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Allimann-Lecourt, Corinne. "Extraction of metals from contaminated land and industrial solid waste using a novel technology (servo process)." Thesis, University of Hertfordshire, 2004. http://hdl.handle.net/2299/14249.
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Selective Extraction and Recovery using Volatile Organic compounds is an emerging technology developed during the 1970s. This process can achieve the extraction of heavy metal contaminants from a matrix using a volatile organic reagent which passes through the feed material and reacts selectively with the desired metal salt, producing a volatile metal complex, removed from the matrix by a carrier gas. Such complexes may be decomposed to produce a pure metal product and regenerate the organic reagent for recycle. Previous studies demonstrated the possible extraction of nickel from low grade laterite ores using ß-diketones (2,4- pentanedione (Hacac)) and Schiff bases (bis(pentan-2,4-dionato)propan-1,2-diimine (H2pnaa)). The current research is directed towards the selective extraction of different metals such as zinc, lead, cadmium, molybdenum, and vanadium from contaminated sediments and industrial wastes (Orimulsion ash, Municipal Solid Waste fly ash (MSW), Pulverized Coal Combustion technology fly ash (PCC)). New extractants and their metal complexes have been synthesised to determine their thermal stability and their volatility. Of those synthesised the metal complexes of tetra-propyldithiophosphoramide (Hprps) are the most thermally stable. Using a thermogravimetric analyser the reaction kinetics of the SERVO process have been studied. Equipment to study the SERVO process on a laboratory scale has been designed and constructed. This equipment has been used to study the extraction of metals from four different matrices (sediments, Orimulsion ash, and two types of fly ash) using three different extractants, with promising results. These sources have been ranked from the best to the least applicable for the technology: Orimulsion ash > sediments > MSW fly ash > PCC fly ash. Of the three extractants studied, Hacac, H2pnaa and Hprps, the latter is the most efficient in terms of the range of metals which can be extracted, the volatilisation temperature, the extent of degradation and reaction time, but unfortunately is also the most expensive. For the fly ashes, of the three ligands studied, Hprps is the preferred extractant followed by H2pnaa. Hacac is not recommended for these sources because extraction is too low.
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Javaid, Saboor. "Development and optimisation of treatment technologies for environmental pollution control." Thesis, Brunel University, 2006. http://bura.brunel.ac.uk/handle/2438/5403.
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A number of sustainable and economically viable treatment methodologies have been developed and optimised to combat environmental pollution problems associated with the diversity and scattered nature of industries in Pakistan. The use of both electro-precipitation and electro-oxidation processes are shown to lead to the removal of dyes from textile effluent streams originating from various operations. The use of the electro-precipitation process, however, leads to a secondary disposal problem because sludge produced has to be disposed of safely. The use of an electrooxidation process does not produce sludge but is unable to remove some of the organic impurities from industrial textile effluent. Both processes do, however, result in colour removal from dye effluents with the degradation of dyes during electro-oxidation proceeding through the formation of different intermediate species before mineralization leading to complete mineralization in 30-40 minutes. Ames tests confirm that the treated effluent streams from both electro-precipitation and electro-oxidation processes are non-mutagenic. The electro-Precipitation process with mild steel anodes is also be used for the treatment of leather effluent streams to remove chromium by producing a mixed Cr(III) / Fe(III) hydroxide sludge. The same treatment process was successfully used for the simultaneous removal of dyes and chromium from mixed textile/leather effluent streams. The electro-precipitation process developed has been successfully tested on pilot scale at a textile mill in Faisalabad, Pakistan. A number of transition metal supported catalysts were shown to be ineffective in the oxidation of volatile organic compounds. For this reason a method of preparing platinum group metal catalysts on inert supports at low temperatures was developed and used to oxidise toluene, as an indicator of volatile organic compounds. The preferred catalyst support is y-A1203 which can be in the form of spheres or washcoated monoliths. In the case of y-A1203 spheres and the y-A1203 washcoated monolith complete oxidation of toluene was achieved at the relatively low temperatures of 236 and 2680C. A number of novel room temperature ionic liquids (RTILs) were synthesised, characterised and their potential application for selective extraction of copper from industrial wastes is also reported. The solubility studies of different metal oxides in the RTIL, 1-(2-cyanoethyl)-3-methylimidazolium bromide, show that it can be used for the selective extraction of copper from industrial waste samples containing other metal oxides. This RTIL has the ability to selectively dissolve, copper, copper oxide and copper sulfide when the reaction is carried out in the presence of water.
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Matthews, R. P. "Adsorption of dies using kudzu, peanut hulls and MDF sawdust." Thesis, Queen's University Belfast, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.397874.
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Baughn, Heulwen M. "Plant-assisted volatilisation of the persistent organic pollutant dichlorobenzene." Thesis, University of Aberdeen, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.440067.
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Environmental fate of pollutants is paramount to their bioavailability, and as such their potential toxicity. Soil bound fractions of persistent organic pollutants (POPs) such as chlorobenzenes are far greater than in any other environmental compartment. This thesis investigates the potential for volatilisation flux of dichlorobenzene (DCB) from soils under planted and unplanted regimes. It was found that volatilisation, not mineralization, is the main route of DCB removal from soil systems. It was also found that planted systems resulted in a significant increase in volatilisation flux from DCB contaminated soil, in comparison to unplanted systems. It is concluded that the plants have two main interactions with the soil that may lead to this increased volatilisation. These are: (i) the plants transpirational influence dries out the soil; (ii) aromatic acids are released by the plants into the rhizosphere in the form of root exudates. It is shown in this thesis that drier soil has increased rates of volatilisation to the atmosphere than wetter soil. It is also shown in literature (Xing and Pignatello, 1998) that aromatic acids released by plant roots as exudates competitively bind to SOM resulting in the displacement of DCB that may subsequently be volatilised from the soil. Both of these factors in combination explain the resulting flux of volatiles from the soil under planting. It is of critical important to recognise volatilisation as a main route of POP flux from soil systems. Many previous studies may have overlooked volatilisation fluxes from soil in favour of the opinion that mineralization is the main route for removal. This may have important implications for the phytoremediation of contaminated soils.
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Alamri, Saad Abdulrahman. "Development and application of a microbiologically based tool kit to monitor and optimise petroleum hydrocarbon bioremediation." Thesis, University of Aberdeen, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.440095.
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The performance of the microbiologically-based tool kit employed in this study was critically evaluated for its ability to monitor the progress of hydrocarbon bioremediation. Different hydrocarbon remedial strategies (nutrient amendment, turning and inoculation) were applied to real hydrocarbon contaminated soil and the treatment effects monitored over a period of 60 days. The overall results of the tool kit evaluation showed that hydrocarbon biodegradation was clearly nutrient limited. The combination of turning and nutrient treatments were demonstrated to be more effective in increasing the rate of hydrocarbon biodegradation (as well as mediating a reduction in soil toxicity) than any single treatment. Although the chemical analysis methods demonstrated a significant reduction in hydrocarbon concentrations in the non-nutrient amended biopile microcosms, the biosensor assessment showed an increase in soil toxicity. Hence, an evaluation of hydrocarbon bioremediation based on analytical methods alone is not always indicative of a reduction in soil toxicity. The tool kit was further applied to biopile microcosms to identify constraints to hydrocarbon bioremediation. Soil matric potential was selected as a potential constraint to hydrocarbon bioremediation because of the great importance worldwide of this environmental control. Four different matric potentials (corresponding to a range of 20%, 40%, 60% and 80% soil water holding capacity) were assessed over a period of 40 days. The overall results from the use of the tool kit showed a strong positive correlation between the rate of hydrocarbon biodegradation and an increase in the soil matric potential tested. The increase in the rate of hydrocarbon biodegradation was also associated with a significant reduction in soil toxicity. Soil matrix was chosen as another potential constraint controlling the rate of hydrocarbon biodegradation. Bioremediation was greatest in the intermediate textured sandy loam (Insch soil). The slowest bioremediation rates were associated with the fine textured clay loam (Cruden Bay). Intermediate rates of biodegradation were associated with the coarse textured loamy sand (Boyndie soil). The chemical analysis showed a significant reduction in the overall hydrocarbon concentrations in the Cruden Bay soil (CB), but the toxicity biosensor assessment showed an increase in soil toxicity. Therefore, an assessment of hydrocarbon bioremediation based on chemical methods alone is not a sound approach, as hydrocarbon reduction does not always correlate with a decline in soil toxicity. The employment of the microbiologically-based tool kit to evaluate and monitor the performance of hydrocarbon bioremediation, complementing standard chemical methods, offers a powerful new approach as chemical monitoring alone does not provide an adequate assessment of the process of hydrocarbon bioremediation.
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Lorenz, Astrid. "Bioengineering transgenic plants to detoxify nitroaromatic explosive compounds." Thesis, University of York, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.441030.
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Rodriguez, Belen Bello. "Development of biosensors and chemical sensors for the determination of metals in water and soil extracts." Thesis, Cranfield University, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.405627.
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Gupta, Manik. "Data-centric energy efficient adaptive sampling techniques for wireless pollution sensor networks." Thesis, Queen Mary, University of London, 2014. http://qmro.qmul.ac.uk/xmlui/handle/123456789/8189.
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Air pollution is one of the gravest problems being faced by modern world, and urban traffic emissions are the single major source of air pollution. This work is founded on collaboration with environmental scientists who need fine grained data to enable better understanding of pollutant distribution in urban street canyons. “Wireless sensor networks” can be used to deploy a significant number of sensors within a space as small as a single street canyon and capture simultaneous readings both in the time and space domain. Sensor energy management becomes the most critical constraints of such a solution, because of the energy hungry gas sensors. Hence, the main research objective addressed in this thesis is to propose novel temporal and spatial adaptive sampling techniques for wireless pollution sensor nodes that take into account the pollution data characteristics, and enable the sensor nodes to sample, only when, an important event happens to collect accurate statistics in as efficient a manner as possible. The major contributions of this thesis can be summarised as: 1) Better understanding of underlying pollution data characteristics (based on real datasets collected during pollution trials in Cyprus and India) using techniques from time series analysis and more advanced methods from multi-fractal analysis and nonlinear dynamical systems. 2)Proposal of novel adaptive temporal sampling algorithm called Exponential Double Smoothing based Adaptive Sampling (EDSAS) that exploits the presence of slowly decaying autocorrelations and local linear trends. The algorithm uses a time series prediction method based upon exponential double smoothing for irregularly sampled data. This algorithm has been compared against a random walk based stochastic scheduler called e-Sense and found to give better sampling performance. EDSAS has been extended to the spatial domain by incorporating distributed hierarchical agglomerative clustering mechanism. 3)Proposal of a novel spatial sampling algorithm called Nearest Neighbour based Adaptive Spatial Sampling (NNASS) that exploits the non-linear dynamics existing in pollution data to compute predictability measures to adapt the sampling intervals for the sensor nodes. NNASS has been compared against another spatial sampling algorithm called ASAP and found to give comparable or better sampling performance.
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Campos, Carlos Jose Alexandre De. "Contamination of shellfish waters with human noroviruses : environmental risk factors and management options." Thesis, Aberystwyth University, 2016. http://hdl.handle.net/2160/4ccf2977-b58c-456c-8a95-a0f8857b21a7.
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This thesis reports research undertaken to better understand the factors that influence norovirus (NoV) contamination in shellfish production areas (SPAs). This knowledge is necessary to develop control measures for mitigating risk from NoV contamination in SPAs. Predictive models were developed for concentrations of NoV (as measured by the reverse transcription polymerase chain reaction method) and Escherichia coli (as measured by the culture method) in shellfish from 31 harvesting sites and climatic, hydrometric, demographic and pollution source-related characteristics of upstream river catchments. Concentrations of NoV in shellfish increased as water temperature decreased and volume of sewage discharges and river flows increased. Concentrations of E. coli increased as rainfall also increased. Field studies were conducted in an estuary and in a coastal embayment to inform risk management measures for these sites. Concentrations of NoV and E. coli and their removal efficiencies were quantified in effluents from primary, secondary and tertiary treatments at four sewage treatment works. Shellfish were placed at different distances downstream of sewage discharges and tested for NoV and E. coli. Dye tracing and drogue tracking studies were conducted to quantify the dispersion and dilution of sewage effluents. Significant NoV reductions were found as sewage treatment levels increased. Activated sludge was more effective in reducing NoV than trickling filters. Norovirus was frequently detected in sewage effluents and in shellfish. It was found that a NoV limit for shellfish established at 100 copies/g would have a high compliance impact on SPAs. The dispersive characteristics of the dye-tagged effluents were consistent with the variation of NoV contamination in the study sites. A buffer zone established at 1,000:1 dilution of estuarine water to treated effluent would afford a high level of public health protection while a buffer zone established at much lower dilution ratios (e.g. 300:1) would represent a much higher health risk.
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Cassidy, Leigh. "Development of a novel technology for enhanced natural attenuation of chlorinated solvents." Thesis, University of Aberdeen, 2007. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=240741.
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Draff was compared to a number of commonly used and commercially available treatments for the amelioration of CAH contaminants. Draff was found to be a suitable treatment under all conditions investigated except when it had been irradiated and performed as well (if not better than) all of the commercial treatments. It was concluded that Draff as a CAH ameliorant merits further investigation involving a scaled-up pilot study in the laboratory which if successful would be followed by field trials at contaminated sites. The quantitative data from the field site which was imputed in to the contaminant visualisation model (Sequence) indicated that attenuation as occurring at the site, albeit rather slowly. The comparison which included revised reaction rates derived from the Draff investigations implied that treatment with Draff at the site would enhance overall attenuation. An investigation regarding the efficacy of biosensors as site evaluation and monitoring tools found that the sensors were of limited value when remediation goals are considered. None of the sensors investigated supplied sufficient sensitivity. It was therefore concluded that the sensors should only be utilised on a cursory “toxic or non toxic” basis. It was concluded that Draff proved effective as an ameliorant for CAH contamination under the conditions tested and merits further investigation at the pilot and potentially the field scale. The contaminant visualisation model proved invaluable for the simplification and analysis of a large data set and furthermore estimated that Draff would enhance attenuation rates at the field site in question.
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Frizzell, Caroline Margaret. "An investigation of food and feed based mycotoxins as potential endocrine disrupting contaminants." Thesis, Queen's University Belfast, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.676471.
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Hormones regulate numerous biological processes. Endocrine disrupting compounds (EDCs) are chemicals which are capable of altering normal hormone signaling, and as a result may contribute to a wide range of adverse health effects. Mycotoxins are one group of compounds which remain to be extensively tested for endocrine disruption. These compounds are toxic secondary metabolites of fungi, which are ubiquitous in nature and may be present in the food and feed of humans and animals, respectively. This study has made use of human in vitro systems to assess the impact of mycotoxins on steroid hormone receptor and non-receptor mediated pathways. The mycotoxins tested included zearalenone (ZEN) and two of its metabolites, α- and β-zearalenol (α-and β-ZOL); alternariol (AOH); the trichothecenes deoxynivalenol (DON), T-2 and HT-2 toxins; ochratoxin A (OTA) and patulin (PAT). The bioassays used included reporter gene assays (RGAs) with natural estrogen, androgen, progestagen and glucocorticoid steroid receptors; and the H295R steroidogenesis model. Endpoints such as nuclear receptor transcriptional activity, receptor expression, hormone production, steroidogenic gene expression or cytosol protein expression were assessed. All of the mycotoxins tested had significant effects on one or more of these parameters when compared to controls. The human in vitro systems used in this thesis have proved very useful for assessing interferences with the endocrine system. As steroid hormones and steroid hormone action is critical to numerous normal biological processes, changes in the activity of steroid hormones due to interference by mycotoxins may serve as a discerning indicator of endocrine dysfunction. This knowledge on the mechanisms of action of various mycotoxins is valuable for risk assessment purposes, which are necessary in order safeguard humans and animals.
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Morgan, Michelle Marie. "Oxidation of mercury in flue gas streams via gold catalysis." Thesis, Queen's University Belfast, 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.677959.
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Mercury emission from coal-fired power plants is a global problem that has garnered attention due to regulations limiting the emission from anthropogenic sources. The three forms of mercury that are all emitted include: elemental mercury (HgO), oxidized mercury (Hg2+), which can both then form particulate mercury. Since current HgO removal technology is not effective, and HgO is extremely toxic, new catalytic solutions are necessary to allow complete oxidation of HgO. The aim of the project was to understand the mechanism of heterogeneous catalyzed mercury oxidation from simulated flue gas streams using supported gold catalysts. It has been proposed in the literature that three mechanisms could potentially be responsible for mercury oxidation: the Langmuir-Hinshelwood, the Eley-Rideal, and the Mars-Maessen mechanisms. To investigate the possible reactions, the mercury saturator was placed either before or after the catalyst bed and in some experiments, the gold catalyst was pre-saturated with mercury. Numerous characterization and gas-phase analysis techniques were used to identify surface changes and species present at both the surface and in the gas stream. For the gold catalysts, it was found that pre-saturating the catalyst with mercury improved mercury oxidation. Based on this data, mercury adsorption is necessary to promote the reaction, not mercury in the gas phase. In addition, the catalysts more efficient at oxidizing mercury generally had increased CI2 production. The gold-mercury amalgam was seen in the STEM images, but only in the more complex gas compositions, not in the N2/Hg gas mixture. In addition to the gold catalysts, ruthenium catalysts supported on titania were tested due to their promotion of the Deacon process. Mercury oxidation and CI2 production was as high with the ruthenium catalysts as with the gold supported catalysts. It is possible that the titania supports are better at producing an oxidized form of mercury, such as HgCI2.
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Miao, Zhi-Feng. "Direct on-filter assays for rapid analysis of hazardous airborne materials captured from the workplace atmosphere." Thesis, University of Sunderland, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.394154.
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Adeola, Samuel Olawale. "Investigation of pollutant removal processes within a combined wetland/aerated pond system for the treatment of airport runoff." Thesis, Middlesex University, 2007. http://eprints.mdx.ac.uk/9495/.
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An integrated system of aerated ponds together with rafted and horizontal flow sub-surface reedbeds has been Installed to treat the glycol-contaminated runoff from two of Heathrow Airport’s susceptible catchment areas the Southern Catchment and the Eastern Catchment. The original plan was to transfer pre-treated water from the latter through the existing fire main which runs around the airport perimeter to the Mayfield Farm Treatment Facility (MFTF) which receives runoff from the Southern Catchment. However this part of the overall Heathrow treatment scheme for surface runoff has not yet been put into operation. Results from monitoring of the treatment system has shown Significant reductions In Biological Oxygen Demand (BOD) throughout the system with levels decreasing by 76 6±10 5% across the constructed wetland cells at the MFTF following high airport deicing fluids applications. However continued exposure to BOD concentrations exceeding the design target of 110 mg/l has resulted in anaerobic conditions being established in the wetland. Background nitrate and phosphate levels observed in two aerated ponds at the MFTF which are used for storage and initial treatment of airport runoff were low Initial results from laboratory experiments conducted to assess the ideal nutrient levels required to support glycol biodegradation in the aerated ponds showed efficient BOD removal (within 5 days) after repeated glycol additions There were also Increases In bacteria populations In aerated pond water samples from average background levels of 107 to 1010 Colony forming units (CFU) per litre Based on the Interpretation of the laboratory experiments a nutrient dosing protocol commenced on 12 November 2004 at the MFTF to ensure that nutrient levels in the aerated ponds were appropriate to treat the contaminated airport runoff received during the winter months Although the BOO levels recorded In the aerated ponds were still high after the commencement of the nutrient dosing regime in November 2004 the BOD removal efficiency of the aerated reservoir following the Influx of high winter BOD load increased to 47 5% (February 2005) from 25 5% recorded In March 2004. In microbiological analyses conducted on the water samples from the MFTF only 18 strains of bacteria, 3 fungal strains and 2 actinomycetes strains were culturable In the laboratory. A combination of API biochemical tests and PCR (Polymerase chain reaction) analyses showed that at least SIX of these bacteria were Pseudomonas species which have been widely reported to have high potential for biodegradation of organic pollutants. However biodegradation experiments conducted using the consortium of the bacteria fungi and actinomycetes Isolates In sterile distilled water dosed With glycol showed that they lacked the ability to efficiently remove the BOD despite the continuously high BOD reductions recorded in some of the natural systems they were isolated from.
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Vincent, Keith John. "Atmospheric particulate matter and historic buildings." Thesis, Middlesex University, 1993. http://eprints.mdx.ac.uk/13435/.
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Atmospheric particulate matter, along with gaseous and precipitation pollutants, were collected close to three historic buildings; Lincoln Cathedral, Bolsover Castle and Wells Cathedral, in order to estimate the amount of sulphur and nitrogen deposited onto each. Results obtained showed that the gaseous dry deposition of both sulphur and nitrogen was the main deposition pathway at Lincoln and Bolsover, whereas as a result of high precipitation amounts the wet deposition pathway was the most significant at Wells. At each sampling site the amount of sulphur and nitrogen deposited as dry particulate matter was relatively insignificant. Estimated washout values for both SO² and SO²⁻, indicated that the former provided approximately 80% of the sulphur in precipitation arriving at the building surfaces. The important role of the gas was reinforced by the significant correlation between the sulphur level in precipitation and sulphur dioxide. The concentration of sulphur in precipitation was found to decrease at high precipitation volumes, whereas the nitrogen concentration was unaffected by precipitation volume. A high sulphate to sulphur dioxide concentration ratio during the summer months was indicative of photochemical oxidation processes. Conversely, during the winter months the relatively low sulphate to sulphur dioxide concentration ratio suggested that sulphate and sulphur dioxide were released from common sources. Multivariate statistical techniques, comprising principal component analysis and multiple regression analysis, were used to infer characteristics about the origin of the constituent parts of the collected particulate matter. In general, three sources of material; secondarily formed particulate matter, sea-salt and crustal material, were estimated to contribute to the collected particulate matter.
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Sayegh, Arwa. "Uncertainties and errors in predicting vehicle exhaust emissions using traffic flow models." Thesis, University of Leeds, 2017. http://etheses.whiterose.ac.uk/17917/.
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Vehicle exhaust emissions predicted based on the outputs of traffic flow models are used directly to calculate traffic-related emissions, but also indirectly as input to 'air quality - human exposure' models. Both of which inform transport and environmental policies aimed at achieving sustainable mobility. To be effective, these must be based on robust modelling approaches that not only provide point-based emission predictions, but also inform these with an interval of confidence that properly accounts for the propagation of uncertainties and errors through the complex chain of models involved. This research develops a data-driven methodological framework to probabilistic average speed-based emission predictions using two widely deployed macroscopic traffic flow models. These are the Cell Transmission Model (CTM), a discretised first-order LWR-type model, and METANET, a discretised second-order Payne-type model. Studying both allows quantitative comparison in their application to predicting emissions. While this research discusses all potential sources of uncertainty in this modelling chain, it focusses on those arising from the traffic flow modelling output. The methodology starts with an ensemble-based optimisation approach to estimate both calibration and validation prediction errors in the traffic flow model, and then proposes a Monte Carlo sampling approach to propagate these to emission predictions. This allows predicting emissions alongside their upper and lower bounds for any time period and road network, at different levels of detail. To ensure transferability of findings, this methodology has been tested on three motorway road networks, one of which operates under Variable Speed Limits (VSL). This permits the quantitative assessment of VSL-modified traffic flow models. In the results of this research, emissions of Oxides of Nitrogen (NOx) and uncertainty associated with their prediction are specifically reported for each road network under study. Finally, this research argues that the methodological framework developed can (and should) be applied to any other (relatively) simple or complex integrated 'traffic flow - emission' modelling chain used as part of policy and decision making process.
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Rousis, Nikolaos. "Identification and screening of biomarkers of human exposure to environmental and food toxicants in sewage." Thesis, Open University, 2017. http://oro.open.ac.uk/50254/.
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Pesticides are active substances with potentially adverse effects on human health, and therefore great effort is addressed to study the relation between their widespread use and human exposure. Human biomonitoring (HBM) is the most widely used and powerful tool to evaluate the exposure of the population to these substances. However, novel approaches are needed in order to give additional information on exposure at population level and overcome the limitations of HBM studies. A novel approach, called Wastewater-Based Epidemiology (WBE), was proposed as an alternative “biomonitoring tool” with the aim to assess the population exposure to organophosphates, triazines and pyrethroids. A specific analytical method based on liquid chromatography tandem mass spectrometry was developed and validated to measure human urinary metabolites of pesticides in influent wastewater. This method was applied to samples collected from wastewater treatment plants of fifteen European cities. Pyrethroids metabolites were suitable to back-calculate human exposure to this class. Generally, the results obtained from wastewater were in agreement with the urinary biomarker levels of HBM studies, taking into account the dilution of urine in wastewater. Spatial differences were observed on pesticide exposure in Italy and Europe and seasonal variations in human intake of pyrethroids were found, as expected, with higher intakes during spring/summer. Mass loads profiles of pesticides metabolites in the different European cities were in accordance with the use reported in the Eurostat official statistics. This novel WBE method can be used for obtaining objective and updated, direct information on the real levels of pesticide exposure in the general population, and can complement the findings of HBM studies. The method can also provide valuable information for public health organizations, such as the United States Environmental Protection Agency, the World Health Organization and the Centers for Disease Control and Prevention.
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Dewar, Marius. "Modelling the two-phase plume dynamics of CO2 leakage into open shallow waters." Thesis, Heriot-Watt University, 2016. http://hdl.handle.net/10399/3093.
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A numerical model of two-phase plume developments in a small scale turbulent ocean is proposed and designed as a fundamental study to predict the near field physicochemical impacts and biological risk to the marine ecosystem from CO2 leakage from potential carbon storage locations around the North Sea. New sub-models are developed for bubble formation and drag coefficients using in-situ measurements from videos of the Quantifying and monitoring potential ecosystem Impacts of geological Carbon Storage (QICS) experiment. Existing sub-models such as Sherwood numbers and plume interactions are also compared, verified and implemented into the new model. Observational data collected from the North Sea provides the ability to develop and verify a large eddy simulation turbulence model, limited to situations where the non-slip boundary wall may be neglected. The model is then tested to assimilate the QICS experiment, before being applied to potential leakage scenarios around the North Sea with key marine impacts from pCO2 and pH changes. The most serious leak is from a well blowout, with maximum pH changes of up to -2.7 and changes greater than -0.1 affecting areas up to 0.23 km2. Other scenarios through geological structures would be challenging to detect with pH changes below -0.27.
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Malgaretti, Maura. "Decabromodiphenyl ether fate in soil system : sorption in soil matrices and new perspective for soil remediation." Thesis, University of Strathclyde, 2016. http://digitool.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=27554.
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Polybrominated diphenyl ethers (PBDEs) have been used for decades as flame retardants in polymeric materials. Products containing lower brominated congeners have been banned because of concerns about their toxicity to neurological, reproductive and endocrinal systems. Restrictions on the use of the deca-BDE mixture, which contains 97% of the fully brominated congener BDE-209, have been initially delayed. Nowadays the addition of BDE-209 to the Stockholm Convention on Persistent Organic Pollutants is under evaluation. BDE-209 fate in soil, as for other hydrophobic organic compounds, is strongly related to soil organic fraction. This thesis investigates BDE-209 sorption kinetics and identifies other factors important for evaluating BDE-209 mobility, degradation and bioavailability in soil. Additionally it moves the first steps in the development of a novel bioaugmentation technique through fungi. For this purpose, HPLC analytical methods and extraction techniques commonly used for hydrophobic organic compounds (HOC) have been tested for analysis of BDE-209 in water and soil samples. The best recoveries values were obtained by evaporation and substitution of water (WES) and by pressurised liquid extraction (PLE) of soil. Regarding BDE-209 sorption in soil, the sorption kinetic profiles for two soil matrixes belonging to the mineral domain (kaolin) and organic matter domain (peat) were studied separately. Sorption on kaolin was much faster than in peat (4 hours compared to more than 10 days). This approach made it possible to identify other important factors influencing BDE-209 sorption and partitioning processes: clay minerals and dissolvable organic matter. In relation to the biodegradation aspect, this thesis investigated the tolerance of P.ostreatus (a specie of white rot fungus with documented mycoremediation ability) to BDE-209. The fungus mycelium in co-existence with a soil bacterium demonstrated the ability to colonised straw contaminated with BDE-209 up to 1 mg/kg. The results encourage further investigation on P. ostreatus ability to degrade BDE-209.
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Montague, William. "The suitability of magnesium phosphate cement for uranium metal encapsulation." Thesis, Imperial College London, 2014. http://hdl.handle.net/10044/1/44117.
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Nuclear waste streams consist of a diversity of physical and chemical forms, requiring a toolbox approach in the application of materials to their disposal. Solid uranium metal wastes constitute a disposal challenge due to their tendency to oxidise, making encapsulation within cementitious waste packages for storage potentially troublesome. MKPC (Magnesium Potassium Phosphate Cement) is being considered as an alternative to Portland cement for U-metal encapsulation due to the potential for lower free water content, lower internal pH and the micro-encapsulation of radioactive isotopes as low-solubility phosphate minerals. In this work the development and characterisation of MKPCs optimised for U-metal encapsulation was undertaken. This included the investigation of MKPC property development under both near ambient and elevated temperature conditions, the performance of MKPC/U-metal wasteform corrosion trials utilising temperature elevation (to 30, 40 and 50 °C) for the acceleration of chemical kinetics, and assessment of the impact of dehydration treatments (at 50, 80 and 110 °C) on the cement properties. In general MKPC exhibited excellent processing and mechanical properties. Other significant outcomes of the work include, firstly, the determination that uranium corrosion rate dependencies in MKPC are dominated heavily by the presence of water over other chemical effects, with an anoxic activation energy of 68 ± 6 kJ/mol. Secondly, the development of a methodology for determining the bound water content of MKPC, which allowed the calculation of the extent of reaction. This enabled analysis yielding empirical strength-porosity and kinetic models of the material, capable of facilitating improved mix design for the tailoring of MKPC properties. Finally, the instability of the K-struvite matrix toward dehydration at temperatures of ≥ 72 °C has been recorded. The work concluded that MKPC has many properties which make it suitable as a general encapsulant, whilst being ultimately unsuitable for U-metal storage without further development around the reduction of water availability.
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Hamilton, Douglas Stephen. "Effects of natural aerosols on climate." Thesis, University of Leeds, 2016. http://etheses.whiterose.ac.uk/16272/.
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Natural aerosols are a key component of many biogeochemical cycles, they define the baseline from which the pre‒industrial to present‒day anthropogenic aerosol radiative forcing is calculated, and they dominate the net effect of all aerosols on the incoming solar radiation. However, their impacts on climate are complex, often nonlinear, and poorly understood; leading to large uncertainties. Global model simulations are used in this thesis to define aerosol regions unperturbed by anthropogenic pollution. On a global annual mean, unperturbed aerosol regions cover 12% of the Earth (16% of the ocean surface and 2% of the land surface) with about 90% of unperturbed regions occurring in the Southern Hemisphere. In cloudy regions with a radiative forcing relative to 1750, results suggest that unperturbed aerosol conditions could still occur on a small number of days per month. However, these environments are mostly in the Southern Hemisphere, potentially limiting the usefulness in reducing Northern Hemisphere forcing uncertainty. Clustering techniques were used to identify natural emissions regimes in the pre-industrial and present-day where biomass burning, biogenic volatile organic compounds, dimethyl sulphide, volcanic sulphur dioxide and sea spray emissions dominate the variance in cloud condensation nuclei concentrations. Regimes are generally located in regions close to each emission source, before significant mixing occurs within the atmosphere with other emission types. These regimes are ideal “natural laboratory” locations for field study of the impacts of each natural emission on aerosol behaviour. When pre-industrial fire emissions from two global fire models are implemented in a global aerosol model, pre-industrial global mean cloud condensation nuclei concentrations increase by a factor 1.6-2.7 relative to the widely used AeroCom dataset. Higher pre-industrial aerosol concentrations cause a substantial reduction in the calculated global mean cloud albedo forcing of between 40 and 88 percent and a reduction in the direct radiative forcing of between 5 and 10 percent. When compared to twenty-eight other sources of uncertainty in our model, pre-industrial fire emissions are by far the single largest source of uncertainty in pre-industrial cloud condensation nuclei concentrations, and hence in our understanding of the magnitude of the historical radiative forcing due to anthropogenic aerosol emissions.
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Hawthorne, Joshua Dean. "Cementitious grouts for ILW encapsulation : composition, hydration and performance." Thesis, University of Leeds, 2016. http://etheses.whiterose.ac.uk/16288/.
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The preferred route to treatment of the vast majority of intermediate level nuclear waste (ILW) within the UK is via encapsulation within a composite cement system. The integrity of these conditioned waste packages must be maintained for hundreds to thousands of years since they will eventually be stored deep below ground in a geological disposal facility (GDF), with this expected to be a permanent route to disposal. A thorough and clear understanding of the hydration, microstructural development, and hence performance, of grouting materials is essential in providing confidence in the suitability of the technology and ensuring that structural integrity is maintained. This project comes at a time of significant uncertainty for the cement industry, as well as the steel industry which has significant ramifications on the availability of blastfurnace slag (BFS, hereafter referred to as slag). Through quantifying the ramifications of changes to supply of either of these materials it will be possible to determine the resilience of the technique to chemical and physical variations, in an effort to futureproof supply. Within this study, grouts prepared with slag and ordinary Portland cement (OPC), at a ratio of 3:1 slag: OPC at a water to binder ratio (w/b) of 0.35, were analysed at 20°C. The impact of OPC composition, slag composition and slag fineness on rate and degree of hydration were assessed. Microstructural development was followed by a number of techniques in 2 and 3 dimensions, with the engineering performance of samples also quantified via a range of testing protocols. Resilience to potential fire scenarios was also investigated through simulated heat-testing of samples and subsequent analysis. Slag fineness is the most significant factor in controlling rate and degree of its hydration within both young and mature pastes at these high replacement levels. Availability of pore space into which hydrates may grow appears to the limiting factor in continued hydration; significant quantities of CH remain after 1 year of hydration, intermixed with C-S-H in a densely filled microstructure.
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Mermigkas, Athanasios. "Micro-electrostatic precipitation for air treatment." Thesis, University of Strathclyde, 2016. http://digitool.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=27901.
Full textAbstract:
Particulate matter suspended in the atmosphere is a major contaminant and is prevalent in urban environs, reducing the quality of air in the places that the majority of humans reside. Medical research has labelled PM2.5 as a potential risk to human health. To combat this issue, new legislation regarding PM2.5 has been passed. Electrostatic precipitators exhibit a drop in efficiency at ~(0.1-1) μm PM diameter. Therefore, the present work is focused on an investigation of microelectrostatic precipitation technology, for improvement of indoor air quality. Initial work included investigation of impulsive positive energisation, in a specially designed single stage, coaxial reactor, utilizing 250 ns impulses superimposed on dc voltage. Precipitation efficiency for coarse and fine powders has been investigated for various levels of superimposed impulsive and dc energisation in order to identify optimal energisation conditions. Further steps were taken to decouple charging from collection stages in order to optimize the air cleaning process to a greater extent. Precipitation experiments were conducted using ambient air and cigarette smoke. Maximum precipitation efficiency was achieved when both stages were energised, under impulsive and dc energisation in each stage respectively. Analytical work regarding PM charging has also been conducted. Lastly, the coaxial precipitator reactor was scaled-up for possible indoor air cleaning applications. Similarly, impulsive energisation combined with dc voltage at the different stages has been used and proved to increase precipitation efficiency. Test fluids used were beeswax candle fumes and ambient air. Simulations have also been conducted to optimize the ESP process. In conclusion, it has been shown that impulsive energisation of ESPs is highly efficient,100% for particles greater than 250 nm, for PM2.5 in concentrations found in indoor environments. This could potentially help in increasing indoor air quality, with all the corresponding health, working efficiency and ultimately state economic benefits it could achieve.
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Lau, Aaron. "Oxidation of soot with modified silver catalysts." Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:138e06c2-ce59-4754-a71a-d2dc0c52ecbe.
Full textAbstract:
As the demand for motor vehicles has soared dramatically with the emergence of rapidly developing countries, the need for regulating vehicle emissions and pollutants is increasingly more important. With the newest regulations for diesel particulate emissions soon to be enforced, there is a great need to catalytically convert soot particles from the exhaust into relatively less polluting carbon dioxide. Here a supported silver catalyst is reported for the soot oxidation reaction. The silver catalyst is protected and supported using various capping agents and metal oxides, and modified using various synthetic methods. The catalysts are then tested with soot using thermogravimetric analysis (TGA) at a reaction temperature up to 700oC. In order for a better design and modification of the silver catalyst, an improved understanding of the interaction between silver nanoclusters and the metal oxide support must be established. XPS and UV/VIS spectroscopy are amongst the techniques used to probe the metal/metal oxide interaction. It is shown that the surface plasmon resonance of silver can be perturbed by the metal oxide support, modifying its band structure. It is also extremely important for the catalyst to be thermally stable up to 600°C for it to be employable in an exhaust system. In-situ XRD can be used to investigate the thermal stability of both the silver and metal oxide species in an oxidising environment. The phase changes, if any, of either species under heating can also provide a better understanding of the metal/metal oxide interaction and ultimately the soot combustion mechanism. It has been demonstrated that different catalyst surfaces can have different catalytic performances. By altering the morphology of the support, preferential growth of one surface can be achieved, thereby modifying the catalytic performance for soot combustion.
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Davis, Davidson Dimabo. "Bioremediation of hydrocarbon contaminated soils and drill cuttings using composting with agricultural wastes." Thesis, University of Newcastle upon Tyne, 2016. http://hdl.handle.net/10443/3414.
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A compost-bioremediation approach was adopted in this study to explore more sustainable and economically viable methods of degrading pollutant hydrocarbons in oil-field drill cuttings and coal tar impacted soils (CTIS). The compost amendments used were agricultural waste products including grass cuttings, spent mushroom compost and straw. Laboratory-scale compost experiments were conducted to test the performance of different compost blends comprised of each contaminated medium and organic amendments in different mix ratios for 53 days. The compost mix type which produced the greatest reduction in pollutant hydrocarbon concentrations was further scaled-up and tested in an outdoor pilot scale compost treatment for 56 days. At the end of the lab-scale treatments, degradations in total petroleum hydrocarbon (TPH) concentrations of 85.1% and 90.6% were recorded for the drill cuttings and CTIS, compared to 36.7% and 28.4% that was achieved in the control experiments, respectively. The concentrations of total n-alkanes and polycyclic aromatic hydrocarbons (PAHs) were significantly decreased in the best performing compost mix types, however most of the 5 and 6-ring PAH compounds in the CTIS treatment compost mix exhibited recalcitrance to degradation and some even appeared to increase in concentration which is ascribed to increased PAH availability to solvent extraction and reduction in the compost mass during the composting-biodegradation process. The best performing compost mix type for treatment of CTIS was subsequently tested in outdoor tumbler compost bins after being scaled-up by a factor of 600; this was found to produce 78% degradation of TPH concentration at the end of the treatment period. Concentrations of total nalkanes and PAHs were also significantly lowered by biodegradation. Low molecular weight (2 and 3-ring) PAHs were almost completely removed and 4-ring PAHs from the coal tar, including fluoranthene, pyrene, benzo[a]anthracene and chrysene were significantly degraded but not the 5 and 6-ring PAH compounds. Phytotoxicity assays showed that the seed germination in the treated matrix was 70% and 20% more, for corn and pea, respectively, 5 days after planting and 78% more for mustard 3 days after planting. Phosphatase enzyme activity was found to decrease in the treated matrices possibly due to the short time between end of composting and testing. The results generated from the chemical and toxicity assays of this study showed the efficacy of the composting treatment for hydrocarbon removal from these contaminated matrices and identified the best performing compost mix types (DGMSt3 and SGSt3) which can be further tested in field scale trials.
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Acton, Joe. "The application of novel mass spectrometric techniques for the analysis of volatile organic compounds in different environments." Thesis, Lancaster University, 2015. http://eprints.lancs.ac.uk/80147/.
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Volatile organic compounds (VOCs) are released into the atmosphere from numerous anthropogenic and biogenic sources. Traditionally VOCs have been measured using offline techniques such as Gas Chromatography-Mass Spectrometry (GC-MS). The development of the proton transfer reaction mass spectrometer (PTR-MS) has enabled the online analysis of VOC’s from both biogenic and anthropogenic sources. This instrument, however, provides little structural information making it impossible to distinguish between isomeric compounds. Here a range of New-PsychoactiveSubstances (NPS) are analysed using the recently developed Selective Reagent IonTime of Flight-Mass Spectrometer (SRI-ToF-MS) demonstrating its ability to distinguish between isomeric compounds. This instrument is then applied to the analysis of biogenic VOCs (bVOCs). Plants emit a wide variety of VOCs into that atmosphere. These compounds play an important role in plant communication and defence, with predatory insects making use of VOC emissions from plants following biotic stress to identify and locate their prey. This process is termed tritrophic signalling. Ozone will readily react with any bVOCs containing an alkene functional group, and as many alkenes (primarily monoterpenes and sesquiterpenes) have been shown to play a significant role in tritrophic signalling it was hypothesised that ozone may disrupt this signalling. This thesis investigates the effect of ozone on tritrophic signalling using a Brassica napus – Myzus persicae – Adalia bipunctata larvae (rapeseed – green peach aphid – two-spotted ladybird larvae) model system. Plant volatile emission was monitored using a PTR-MS and SRI-ToF-MS which enabled the better detection and identification of bVOCs than is possible using a traditional PTR-MS. Following ozone fumigation of B. napus it was shown that a large number of oxygenated compounds are emitted by the plant and that the emission of monoterpenes and sesquiterpenes from a plant chamber is reduced. However, ozone fumigation of the plant leaves was shown to have no impact on the emission of bVOCs below ground. Using a Y-tube olfactometer it was shown that ozone at environmentally-realistic mixing ratios (ca. 100 ppbv) disrupts the ability of M. persicae to locate a host plant. Ozone was also shown to disrupt tritrophic signalling by inhibiting the location of prey by A. bipunctata larvae. This disruption in tritrophic signalling was shown to be caused by degradation of bVOCs via ozonolysis and not changes to bVOC emission from the plant. Finally fluxes of VOCs above a temperate forest canopy were recorded using PTRMS and a Proton Transfer Reaction-Time of Flight-Mass Spectrometer (PTR-ToFMS) enabling a direct comparison to be made between these instruments during field scale measurements.
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Valach, Amy C. "Volatile organic compound fluxes and mixing ratios in two contrasting atmospheric environments : London and the Amazon rainforest." Thesis, Lancaster University, 2015. http://eprints.lancs.ac.uk/76898/.
Full textAbstract:
Volatile organic compounds (VOCs) from biogenic and anthropogenic sources are important constituents of the atmosphere with effects on air quality and climate. Current uncertainties in measurements and models relate to their roles in tropospheric ozone and secondary organic aerosol formation, yet there have been few measurements of their fluxes from contrasting chemical environments. Additional measurements with greater spatial and temporal resolutions are required to constrain uncertainties in atmospheric chemistry and climate models. This thesis presents long-term measurements of VOC fluxes and concentrations in two contrasting environments: central London and the Brazilian Amazon. VOC concentrations were quantified by proton transfer reaction-mass spectrometry and fluxes were calculated using the virtual disjunct eddy covariance method over a period of several months at sites in central London and the Amazon rainforest. In central London, traffic was found to be the main source of aromatic compounds. Oxygenated compounds and isoprene showed strong correlations with light and temperature, suggesting biogenic, evaporative, or secondary atmospheric origins. The seven VOCs measured in central London had a five-month average total emission rate of 1.4 mg m-2 h-1. Comparisons with local and national emission inventories showed that modelled emissions were largely underestimated. Measurements of isoprene and monoterpenes at the remote ZF2 site in the Amazon rainforest showed an 11-month average total emission rate of 2.7 mg m-2 h-1 with considerable seasonal variation, which could not be accurately reproduced using the light and temperature based MEGAN algorithms. This thesis presents the first long-term VOC flux measurements providing information at high temporal resolutions on seasonal variability at an urban site and a pristine tropical forest site. They confirm that the Amazon rainforest is an extremely strong source of reactive carbon to the Earth’s atmosphere exceeding emissions from a developed megacity, such as London, per unit area.
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Alnusaire, Taghreed Stum. "The potential for wheat roots in phytoremediation of phenolic compounds." Thesis, Bangor University, 2016. https://research.bangor.ac.uk/portal/en/theses/the-potential-for-wheat-roots-in-phytoremediation-of-phenolic-compounds(f6f6c65f-8ca5-4a5d-a011-ecd4bd3e3afa).html.
Full textAbstract:
Soil pollution is a global problem, resulting in a major international research effort using bioremediation technology to exploit plant and microorganism in the removal of contaminants. Phenolic compounds are major pollutants from industrial effluents and consequently are present in many soil and water systems throughout the world. Phytoremediation studies in soil contaminated with phenolic compounds are a challenge. The rhizosphere is an extremely dynamic zone, both spatially and temporally. In order to understand the complex rhizoremediation processes (including root-microbe reactions), there is a need to study the biophysical interactions at the root/soil interface. However, this is limited by sampling and analysis techniques. A modified (SiCSA) Single Cell Sampling and Analysis technique using fine glass microcapillaries was used in an attempt to overcome this issue. This micro-scale technique was used to quantify the polar phenolic compounds such as syringic acid. Phenols of lower polarity offer different technical challenges as they rapidly dissolve in paraffin oil, which was used to prevent the evaporation of micro samples. As a result, a conventional ‘macro’ approach was also used. A microcosm system for plant growth was used to facilitate access to soil and roots. The phenolic compounds were analysis using Capillary Zone Electrophoresis (CZE). The two selected plants, rye and wheat, have the ability to speed up the removal of two selected phenolic compounds from soil after their addition. The pathways through the plant of phenol (an artificial compound) and syringic acid (a biological compound) are different. Different strategies of phytoremediation of these phenolic compounds in soil was demonstrated in wheat. Phenol was absorbed into the root and transported to the leaf. Phenol seemed to be partially accumulated in the leaf, while some amount evaporated through stomata to the atmosphere. Syringic acid was taken up by the root and seemed to be metabolized there within less 2 hours. No evidence was found that this compound is rapidly transported to the leaf. Phytoremediation occurs in ways previously reported, such as metabolism, accumulation and evaporation. In conclusion, although microbial processes probably dominate the removal from soil of phenolics studied, both rye and wheat behaviour contributed to the removal of phenolic compounds. This indicates the potential of using them in phytoremediation.
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Karra, S. "An investigation of traffic related pollutants dispersion in heterogeneous street canyon." Thesis, University College London (University of London), 2012. http://discovery.ucl.ac.uk/1389332/.
Full textAbstract:
In urban areas, traffic is a major source of air pollution. Concentrations of pollutants are observed to be particularly high near ground level in street canyons, where tall buildings and different obstacles limit the ventilation. This impedes the dispersion of pollutants, contributing to build-up of harmful substances, which have an adverse effect on human health and comfort. Consequently, there is a desire to understand the mechanisms that contribute to street level ventilation especially in exploring the effect that heterogeneous layout of a street canyon has on the ventilation level. It has been established that extent of ventilation is dependent upon the background meteorological conditions, and how they interact with the building geometry. There is further interest in investigating the effect of the ambient conditions in heterogeneous street canyons. In the existent urban areas it is necessary to improve the ventilation for better comfort of the people who live in these areas and the surrounding environment. Elements that might exist in the street such as traffic lane position, parked cars or other obstacles may also have an effect on the distribution of pollutants or flow regimes. This thesis focuses on exploring the flow features and distribution of traffic-related pollutants in heterogeneous street canyons. Comparisons are made between symmetric and non-symmetric geometrical street layouts. In addition, this thesis examines the effect of local street parameters, such as the position of traffic lanes and the placement of parked cars, on the distribution of pollutants in heterogeneous, symmetrical and non-symmetrical canyons. A heterogeneous street canyon in Cyprus is used as a case study to examine the ventilation in these types of street canyons. This street was modelled in the lab, in a water channel, applying simultaneously the advanced imaging techniques of Particle Image Velocimetry (PIV) and Planar Laser Induced Fluorescence (PLIF). The same techniques were also applied to models of symmetrical and non-symmetrical canyons under constant perpendicular ambient conditions. A field measurement campaign was undertaken in the real heterogeneous street canyon in Nicosia to examine the flow fields and pollution distribution under variable ambient conditions and traffic flow rate. A comparison was made between the results obtained under constant and variable ambient conditions. The heterogeneity of the canyon was found to influence the distribution of pollutants at street level. The overall pollution levels are lower in the heterogeneous 4 street canyon than in symmetrical and non-symmetrical canyons. Flow fields are found to vary along the length of the heterogeneous street canyon and each cross section behaves individually according to its own geometric layout, leading to a different distribution of pollutants in each cross section. In addition, the existence of gaps (either only at the upstream side or both upstream and downstream side) is found to produce higher level of turbulence resulting in lower pollution levels near the ground level than can be expected for a symmetrical canyon. However, the existence of a gap only at the downstream side did not enhance the ventilation near the ground level at this side of the canyon. In this case the pollution levels were slightly higher compared to the locations along the length of the canyon where the gap was at the upstream or both sides. The local street parameters influence the distribution of pollutants near the ground level at all the examined street geometries. It was found that moving the traffic lane near the downstream area and the placement of parked cars on the upstream area produces major reductions of pollutants. The variability of the ambient wind was found in the field to produce different flow regimes compared to the case when the ambient flow was constant and perpendicular. At all the examined locations the flow was three dimensional. Despite this difference in the flow regimes the pollutants have similar distribution to those observed in the laboratory study. One possible explanation is that the local street parameters (such as the location of the traffic lane and the placement of parked cars in the street) had a greater impact at street level compared to the variability of the wind. Finally, results indicate that the recurrent, frequent variations in building heights along the length of the street contribute to significantly increase the dilution of pollutants near ground level, where the implications to pedestrian health and comfort are greatest.
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Bacon, Charles Guy David. "Surface complexation of Pb and Zn onto birnessite (δ-MnO₂) : soils and groundwater controls on pollution in soils and groundwater." Thesis, University of Bristol, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.687595.
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A molecular-level understanding of the surface complexation reactions between ecotoxic heavy metals and mineral surfaces is essential for determining their environmental fate. Many studies have investigated the surface complexes of elements on different mineral surfaces, but few studies have performed surface complexation modelling to determine the specific equilibrium constants for these complexes. To the best of our knowledge, no study has applied appropriate equilibrium constant data from surface complexation modelling for determining the stability and bioaccessibility of ecotoxic elements at actual sites of concern. This is the goal of this study. Chapter 1 is a review of the scale of metal contamination in the UK, the sources and the common methods of environmental impact assessment. This Chapter describes how surface complexation models can provide the most accurate means of modelling metal partitioning onto environmentally relevant mineral surfaces. Chapters 2 and 3 are surface complexation modelling studies of Pb and Zn respectively, onto the highly reactive and environmentally ubiquitous Mn oxide mineral phase, birnessite (o-Mn02). Chapter 4 is a geochemical survey of the River Axe Valley in Somerset, England. This area has been identified as having a high risk of contamination from mining, but has not received the same depth of investigation compared to other areas in the UK. This Chapter provides background information on this area, and investigates the mineralogy of the mine site soils, the caves through which the surface waters drain and the River Axe floodplain. The surface complexation models derived in Chapters 2 and 3 are successfully applied to model the partitioning of Pb and Zn in this setting, and assist in understanding the possible risk from the mine-derived metal-bearing sediment. Chapter 5 is a summary of the information required for the successful application of surface complexation models for site investigations in general, and gives an appraisal of their uses in future studies.
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Maciel, Helena. "Ecotoxicity testing and remediation potential of petroleum components : use of diagnostic luminescent biosensors." Thesis, University of Aberdeen, 2003. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU179185.
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The bacteria E. coli HB101, E. coli DH1 and P. fluorescens 10586r were lux marked with the multicopy plasmid pUCD607. P. putida F1, was chromosomally marked by the insertion of the mini-Tn5 transposon. Growth and bioluminescence of E. coli HB101, E. coli DH1 and P. fluorescens 10586r were characterised and optimised for freeze-dried cultures (E. coli HB101 and E. coli DH1). The toxicity of aqueous solutions of MTBE, benzene and naphthalene was investigated using the biosensors, E. coli HB101, E. coli DH1, P. fluorescens 10586r pUCD607, and luc-marked, S. cerevisiae. The biosensors responded to high environmental concentrations. The EC50 values were comparable for E. coli DH1 and P. fluorescens 10586r. The yeast was shown to be quite resistant to MTBE. There is a general use of solvents, such as DMSO, to solubilise or extract compounds with high octanol water partition coefficients. This has a distorted effect on their actual toxicity. This was shown by the development of QSARs using the toxicity response of E. coli HB101 and plotting this against hydrophobicity. Bioluminescent based biosensors are useful tools not just only to assess toxicity but also to allow quantification and prediction of the remediation potential of certain compounds which enables a more complete assessment of their impact. A catabolic biosensor, P. putida TVA8, was used to further investigate pollutant relations. Correlating E. coli DH1, P. putida F1 QSARs with a QSBR developed for P. putida TVA8 allowed a better understanding of enzymatic specificity and toxicity. To evaluate the fate of MTBE in the environment it is necessary to investigate how it interacts with other co-contaminants. The determination of interactions is crucial to assessing environmental damage. Using the biosensor response and a model it was possible to investigate the nature of interactions. For MTBE:benzene mixtures, there was no increase in combined toxicity to E. coli DH1 and P. fluorescens 10586r. E. coli HB101 response had a different pattern and for low concentrations of MTBE:benzene synergistic interactions were observed. For MTBE:naphthalene, overall, the effect was additive. The toxicity of petrol containing MTBE was assessed since this is the major source of introducing MTBE in the environment. MTBE did not change the toxicity of petrol to the receptor tested. To assess the toxicity of MTBE's degradation products, E. coli DH1 was used. Most of MTBE degradation products were less toxic than MTBE, although TBF and formaldehyde had lower EC50 values. MTBE's effect as a solvent on co-contaminant specific biosensors was evaluated. MTBE changed the cell permeability in P. fluorescens HK44. Nevertheless P. putida TVA8 an E. coli DH5a showed no induction.
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Jamaludin, Jeenath Banu. "Genetic susceptibility to traffic related pollutants." Thesis, King's College London (University of London), 2014. https://kclpure.kcl.ac.uk/portal/en/theses/genetic-susceptibility-to-traffic-related-pollutants(797ff6a3-cc33-4553-b7da-99e14ea9de4e).html.
Full textAbstract:
A strong correlation exists between acute and chronic exposure to traffic derived pollutants and poor respiratory health. Specifically, diesel exhaust (DE) components such as NO2 and fine particles (PM2.5) have been related to impaired lung growth and increased respiratory and allergic symptoms in children and adults living near busy roads. On this basis, implementation of strategies to reduce diesel emissions and improve air quality should provide a measureable improvement in the respiratory health of populations resident in high traffic areas. The introduction of the London Low Emission Zone (LEZ), the largest of its kind in the world, covering an area of 2,644 km2 and a resident population of more than 8 million, provided a unique opportunity to examine this, as well to quantify the impact of DE emissions on the respiratory health of London's population. London’s Low Emission Zone was introduced as part of the Mayor of London’s Air Quality Strategy, with the aim of improving public health through targeted reductions in tail pipe emissions from the most polluting vehicles entering the city. The objective of decreasing PM10 concentrations was to be achieved by restricting the entry of the oldest and most polluting diesel vehicles (heavy goods vehicles (HGVs), buses and coaches, larger vans and minibuses) into Greater London by providing incentives to operators to upgrade their fleets to lower emission vehicles. The Low Emission Zone was enacted as a phased tightening of emission standards for each vehicle class, with the first phase coming into force at the beginning of February 2008. This applied to HGVs greater than 12 tonnes and restricted entry to the zone for those vehicles not meeting the Euro III emissions standard for PM10. Phase 2 followed in July 2008 widening restrictions to include HGVs between 3.5 and 12 tonnes, buses and coaches. Vehicles failing to meet these emissions standards within the zone were initially charged £200 (£100 for vans an minibuses) per day, with enforcement achieve using cameras to identify the registration numbers of vehicles and the Driver and Vehicle Licensing Agency (DVLA) database to identify a vehicle’s emissions standard. In its initial configuration phase 3, restricting access to heavier LGVs and mini-buses not meeting Euro III PM standard was planned for October 2008. In our initial four year study design we planned to examine the respiratory health of cross sectional panels of 8-9 year old school children living within the zone from November 2008; encompassing the first two years post phases 1 and 2, and two years post phase 3 (see Figure s1). As the subject recruitment and health assessments began in November 2008, this afforded us the opportunity of addressing the impact of the third phase of the LEZ, by comparing lung function and respiratory symptoms in the two years before and after phase 3. We also planned to examine year-on-year changes related to projected reductions in vehicle emissions as newer cleaner vehicles entered the fleet, independent of the LEZ, and the increased period the children had lived within the zone, from 11-15 months (11.5-13.9% of lifetime) in year 1, to 44-60 months (45.8-55.6%) in year 4. During annual school visits, children were asked to perform spirometry and provide a urine sample for the assessment of exposure (metals, reflective of defined traffic sources) and response biomarkers (oxidative damage). In addition, the parents/guardians of the children completed a questionnaire on respiratory / allergic symptoms and the children provided DNA samples to investigate genetic susceptibility to the detrimental effects of air pollution, focusing on a panel of antioxidant and xenobiotic genes, as well as a genetic marker associated with the onset of childhood asthma. In May 2008 Boris Johnson was elected the new Mayor of London, with a manifesto commitment to review ongoing traffic management schemes within the city, including the LEZ, and on the 2nd February 2009 he announced intention to cancel the third phase of the LEZ, subject to the outcome of a public consultation later in the year. This political decision therefore robbed us of the original intervention we were planning to address in our original design. Following a further consultation, the scheme was finally fully implemented and expanded on the 3rd of January 2012 (LEZ phase 3 and 4), with Euro III emission standards for minibuses and vans and a further tightening of emission standards (Euro IV) on Lorries over 12 tonnes, between 3.5-12 tonnes, as well as buses and coaches. In light of this development we obtained additional funding to examine furthers panels of school children in Nov 2012 - March 2013 and Nov 2013 - March 2014, extending our study to six years, allowing a formal assessment of the three years pre and two years post LEZ phase 3 and 4, with year 4 straddling the periods of phase 3 and 4 implementation (Figure s2). Children at the conclusion of the study in March 2014, who have been resident within the LEZ since birth will have lived within the zone for 68.8-83.3% of their lives. The data presented in this thesis is therefore based upon the first three years of the study and therefore constitutes a baseline analysis of the relationship between air pollution in London and our key respiratory endpoints prior to the formal evaluation of Phase 3 and 4 in 2014/15. In the first experimental chapter (Chapter 3) I evaluated the associations between traffic-related air pollutants and respiratory/allergic symptoms within our cross-sectional children's cohort. Information on respiratory/allergic symptoms was obtained using a parent-completed questionnaire and linked to modelled annual air pollutant concentrations based on the residential address of each child, using a multivariable mixed effects logistic regression analysis. Exposure to traffic-related air pollutants was associated with current rhinitis (NOx [OR 1.01, 95% CI 1.00-1.02], NO2 [1.03, 1.00-1.06], PM10 [1.16, 1.04-1.28] and PM2.5 [1.38, 1.08-1.78], all per g/m3), but not with other respiratory/allergic symptoms. Furthermore, over the first three years of the operation of London's LEZ I did not observe evidence of reduced ambient air pollution levels, or year-on-year changes in the prevalence of respiratory/allergic symptoms. I found no evidence that these associations were modified by polymorphisms in gasdermin B, located at the chromosome 17q12, associated with the risk of childhood asthma. These data confirm previously reported associations between traffic-related air pollutant exposures and symptoms of current rhinitis. Importantly, whilst the data is largely confirmatory, this remains one of the few studies that has addressed respiratory symptoms in urban children over the period of rapid dieselization within Europe. In Chapter 4 I report evidence of reduced lung volumes (FVC - Forced Vital Capacity) in children living within the study area. This negative association was small and most strongly associated with modeled annual NOx concentrations, at the residential address level. A straightforward method to discriminate between acute versus chronic pollutant effects was developed for the study. Acute exposures were assessed by scaling annual mean concentrations according to a ‘Nowcast’ factor calculated for each pollutant for the period immediately prior to the health assessment. This factor was defined as the ratio between concentrations measured by a local subset of London Air Quality Network monitoring sites in the prior period, and the annual mean measured by the same sites. Using this approach I was able to dissect out whether basal lung function was related to short or long term exposures. In the absence of relationships between FEV1 and FVC with 24 hour and 7 day average exposures, the association between FVC and annual pollutant exposures was interpreted as reflecting evidence of impaired lung growth. In this initial analysis I found no evidence that polymorphisms in the commonly studied glutathione S transferases (GSTM1 and GSTP1) and NADPH quinone oxidoreducatse (NQO1) genes modified the association between lung function and pollutant exposure. In a secondary analysis I examined whether polymorphisms in Cytochrome P450, family 1, subfamily A, polypeptide 1 (CYP1A1) and the Aryl hydrocarbon receptor (AhR) might modify the association between pollutant exposures and lung function, based on their role in the xenobiotic metabolism of Polycyclic aromatic hydrocarbons (PAHs). This is the first time polymorphisms in these genes have been investigated in the context of air pollution – lung function interactions.