Recently, there has been increased concern about the potential impact of powerboating on freshwater ecosystems. In the case of Loch Lomond, such concern led to the commencement of a programme of boat counting surveys in 1989. In these surveys, it was found that maximum boat numbers are increasing in Loch Lomond. As a logical progression from these surveys, the present study examined the impact of powerboat chemical pollution on the water quality of Loch Lomond. In the first stage of this study, the scale of powerboat pollution was assessed. This was achieved by constructing a simple mathematical model to estimate the total annual discharge of hydrocarbons (HCs) from powerboat emissions into Loch Lomond. By using boat census data and published information about the emission rates of different types of powerboat engines, the total annual input for Loch Lomond was estimated at 25.50 tonnes in 1989 and this input has greatly increased since then. This indicates that there is real potential for hydrocarbon (HC) pollution of Loch Lomond from powerboat operation. Most of the HC material discharged emanated from speedboats powered by outboard motors. To identify and quantify HC pollutant compounds entering water from outboard engines, Gas Chromatography-Mass Spectrometry (GC-MS) analysis was performed on water subject to a controlled pollution discharge from an outboard motor. Altogether, 47 compounds were detected in this exhaust-polluted water (EPW), with most of these being volatile aromatic HCs, such as benzene and alkylated benzenes. Water samples were also taken from three sites in Loch Lomond on two occasions: once in winter, during negligible boat activity and once in summer, at a time of high powerboat activity. No HCs were detected in winter, but some volatile aromatic HC compounds were clearly detectable in summer. These compounds were the same as those most abundant in EPW and found in similar relative proportions. Further experiments in this study involved the analysis of a large number of water samples. To enable this, it was necessary to develop an appropriate new method for the analysis of powerboat exhaust pollutants, which are mostly aromatic HC. All aromatic HCs fluoresce and the new method involved fluorescence spectroscopy analysis, following sample purification by normal-phase column chromatography. This technique is non-destructive allowing subsequent confirmatory analysis by GC-MS. It was found that the new method was fast, precise, highly sensitive and specific to volatile aromatic HCs. The capability of measuring HCs in a large number of samples allowed previously unfeasible experiments investigating: 1) The geographical distribution of powerboat exhaust HCs in Loch Lomond. 2) The depth profile of powerboat exhaust pollutants in the top 1.5 m of the water column. 3) Recovery of water quality, following peak weekend boat activity in summer. It was found that: 1) Volatile aromatic HCs from powerboat exhaust are detectable over much of Loch Lomond on days of heavy powerboat activity, with concentrations of up to 37 ug.l" occurring. 2) Pollutant HCs are found at depths of at least 1.5 m, and are not confined to the surface microlayer (100 urn), The HC distribution with depth was mostly uniform in the field and this was confirmed in controlled experiments in a tank. 3) Recovery of water quality was difficult to demonstrate in the field, possibly as pollution incidents occur continually during summer. 4) HC concentration declined in controlled experiments, in which water was subjected by a controlled pollution discharge from an outboard motor. The time taken for the HC concentration to reach 50 % of the initial HC loading varied but was approximately 7 - 9 days. The toxicity of EPW was investigated by performing 24 hour LC50 (Lethal Concentration for 50 % of test organisms) tests, using the water flea, Daphnia magna (an international standard test organism). The mean LC50 recorded in this study, expressed as the total concentrations ofHC compounds, was 3.72 mg.l". Previous studies suggest that multiplying the Le50 for D. magna by an application factor of 0.001 gives an approximate safe level of a pollutant. Using data collected in this study, a safe level of exhaust He compounds of 3.72 Jlg.r1 would result. In summer, during times of high powerboat activity, such levels are exceeded at many locations in Loch Lomond. The current study has shown that He pollution from a relatively small number of inefficient powered recreational craft using Loch Lomond poses a potential threat to the maintenance of water quality.

Incineration can reduce the mass and volume of municipal waste significantly but produces solid waste in the form of bottom ash and air pollution control (APC) residues. Landfill is currently the most commonly used disposal option for these ash residues, however, the impact of hazardous compounds in these wastes on the environment during landfilling is becoming more widely appreciated and cheaper, alternative, management options need to be explored. In this research, the treatment of these municipal solid waste incinerator (MSWI) residues by accelerated carbonation is investigated and compared with naturally aged ashes. Both bottom ash and APC residues were carbonated in an atmosphere composed of gaseous CO2. It was found that the carbonation of calcium oxides/hydroxides resulted in the rapid formation of calcium carbonate and that silicate compounds were hydrated. The reduction of pH from 12-12.5 to 7-9 observed upon carbonation was associated with a reduction in availability of soluble salts and meals. Carbonated ash had a higher buffering capacity to acid attack when compared to the untreated, non-carbonated, ash. The bottom and APC ashes sequestrated between 6% and 13% CO2 (w/w dry weight), respectively upon carbonation; and this may be important where the reduction of greenhouse emissions to the atmosphere is concerned.

The objective of this thesis is to develop a standard, simple methodology for the assessment of health in areas near sources of pollution. This methodology should make use of readily available data and computing facilities. A literature review on previous studies on the subject was carried out in order to draw from existing experience. A total of twenty-five studies on health near sources of pollution were reviewed. These studies were carried out between 1982 and 1991, most of them in Britain, two in France. The types of pollution sources studied ranged from waste dumps to incinerators, to nuclear power stations. Each study was described, stressing on their respective backgrounds, building on geographical (study) areas, data, analysis and results. Brief synopses of the studies were next grouped, according to those using conventional epidemiological methods and more innovative ones. Finally, it was concluded from the review that the methodology intended should be descriptive, making use of routinely collected data, with a study area based on small geographical divisions (small areas) and taking into account socio-economic differences over its study area. In the absence of accurate data on pollution levels, and from the previous experience of one of the studies reviewed, circular study areas centred on the source of pollution and subdivided into rings were used, with distance of each ring to the centre as a proxy indicator of levels of pollution. The new methodology was found valid and the objective of the study was met. It compared favourably with previously reviewed methodologies. The methodology is intended to be used as a descriptive, exploratory tool, whose findings may warrant further analytic studies, which the method is not designed to, and can not, replace. The use of routinely collected data greatly facilitated the study, although caveats for future studies exist on them. Distance as a surrogate for exposure is seen as a simplistic approach, but in the absence of reliable exposure data it is a useful one. Standardization by Deprivation category has also been found useful to account for factors for which little data exist.

A cleaner use of fossil fuels supported by Carbon Capture and Storage (CCS) techniques is considered to be one of the main short-term strategies for addressing the global climate change problem. However, potential CO2 or CO2/SO2 seepage during some of the phases of a CCS project not only reduces its performing efficiency, but also impacts the local environment, which could have further impacts on human health. It is therefore essential to assess the potential risks and provide evidence that the impacts are well understood. Moreover, studying the effects of CO2 leakage is useful for identifying monitoring parameters if the leakage does happen, leading to the development of new approaches in detecting CO2 leaks. Accordingly, this research is carried out to assess the relevant impacts on the local environment of CO2 leakage, focusing on the environmental impacts caused by CO2 seepage associated with various soil types, mostly on the soil geochemical changes, which is currently lacked. As a cost effective approach, this research was carried out with two types of well controlled laboratory experiments: Stage I- Closed reactor experiments and Stage II- A flow through column system (designed by the author). As a supplementary study to the research of the ASGARD site, Stage I experiments were carried out with soil samples collected from the ASGARD site and gave directions for Stage II column system design. Stage II experiments were carried out with two contrasting mono-mineral sediments considering sensitivity to CO2 gas, Trucal 5 and Trucal 6 (limestone sand of different particle size) and silica sand. Certain limitations of this research have to be considered. Firstly, highly idealised samples were used in the experiments instead of true soils and there was no heterogeneity in the samples used, which is not representative of the full complexity of a natural system. Secondly, the scale limitation of the laboratory work would lead to a higher gas/mineral ratio compared with field conditions. Therefore, results from the laboratory work cannot simply represent all the soils in the field, except the specific soil related problem and the results are better to be used to demonstrate the conditions where the soils/sediments are surrounded by high levels of CO2, such as the ones nearby a leaking injection well or along a fracture/fault. Nevertheless, this study is believed to provide a step towards understanding the potential impacts of CO2 seepage in soil, and potentially to be useful as a mean of identifying indicators of related problems when applying to the full-scale design, leading to the development of new approaches in detecting CO2 leaks. Throughout the experiments, the experimental apparatus (the continuous column system) newly designed by the author was run successfully, providing an alternative way in respect to the majority of soil-column studies for assessing issues of CO2 seepage. The main impact of CO2 emissions on soil properties is to drop the pH which triggers metals mobilisation from soils (all within safety limits to plant growth). The change of pH associated with both limestone and silica sand indicates that pH is an excellent parameter to indicate the CO2 intrusion into sediments once the background is set. The response of calcium (Ca) to CO2 flux highlights that carbonate minerals are sensitive to CO2 increase and could possibly be used as a parameter to monitor CO2 leakage once the baseline for the pre-injection concentration is set.

Future energy supply infrastructure schemes for the built environment are set to consist of a diverse mix of distributed generation technologies, increasingly stringent local emissions reduction targets, and potentially complex ownership structures. This thesis presents a new modelling method that integrates technical design, green house gas emissions analysis and financial analysis models for new build multi energy vector systems. The model was used to compare and characterise several alternative heating technology options for the carbon constrained design of a generic UK market town residential development. Of the options examined, natural gas combined heat and power based district heating was shown to provide the least cost solution for projects built before 2020. Beyond 2025, electric heat pumps provided the cheapest option in response to the decarbonisation of the grid supplied electricity. The integrated model was used as the basis of an optimised infrastructure design tool. This was applied to determine the least cost energy supply technology mix for a new build community redevelopment scheme at Ebbw Vale, South Wales. It was shown that both the optimal design and corresponding optimal cost is dependent upon the year of build completion for the project and the

Water and environmental resources which provide opportunities for households are threatened by human activities that leads to pollution. The research objectives were to understand the contribution water makes to the livelihoods of urban and peri-urban households; the factors influencing perceptions, attitudes and behaviour in relation to surface water and environmental quality, and measures for promoting community participation in water and environmental management. Ten communities were selected in Accra and its surrounding communities to reflect different levels of infrastructure provision for the study. Four focus group discussions were held in each community, with a mixed group, men, women, and young adults. Issues which emerged were investigated further in a structured household questionnaire survey involving 443 respondents. Key informant interviews were held with the most important government and non government regulatory, research and service provision departments and organizations in water, sanitation, and the environment sectors. Water samples from some of the selected communities were analyzed in the laboratory to compare with respondents’ perceptions. Among the households surveyed, 59.14% were engaged in a water dependent occupation which contributed over 80% of household income in some cases. The study also found that perceptions of water and environment are influenced by the existing social and cultural setting. There were common concepts which helped groups to interpret and make meaning from their environment. The prospects for successful water and environmental interventions can be enhanced through an understanding of this local knowledge and perceptions. There was no clear relationship between attitudes and environmental behaviour or between attitudes and socioeconomic status. Actual behaviour was influenced by ability to pay for services, their availability and the influence of shared community norms. Although citizen participation in water and environmental management decision making is very limited at present, community collective action holds good prospects for future interventions in water and environmental management.

Crowdsourcing is an approach to replace the work traditionally done by a single person with the collective action of a group of people via the Internet. It has established itself in the mainstream of research methodology in recent years using a variety of approaches to engage humans in solving problems that computers, as yet, cannot solve. Several common approaches to crowdsourcing have been successful, including peer production (in which the participants are inherently interested in contributing), microworking (in which participants are paid small amounts of money per task) and games or gamification (in which the participants are entertained as they complete the tasks). An alternative approach to crowdsourcing using social networks is proposed here. Social networks offer access to large user communities through integrated software applications and, as they mature, are utilised in different ways, with decentralised and unevenly-distributed organisation of content. This research investigates whether collective intelligence systems are facilitated better on social networks and how the contributed human effort can be optimised. These questions are investigated using two case studies of problem solving: anaphoric coreference in text documents and classifying images in the marine biology domain. Social networks themselves can be considered inherent, self-organised problem solving systems, an approach defined here as ‘groupsourcing’, sharing common features with other crowdsourcing approaches; however, the benefits are tempered with the many challenges this approach presents. In comparison to other methods of crowdsourcing, harnessing collective intelligence on social networks offers a high-accuracy, data-driven and low-cost approach.

A large body of data is analysed of the flow of concentrated sewage sludge through straight pipes. Mathematical models are obtained of the laminar and turbulent flow of each main category of sewage sludge. The sludges are modelled as time-independent, non-Newtonian relations between shear stress, rate of shearing strain, and solids concentration. Due to the inhomogeneity of sewage sludge, error analysis becomes pivotal to the data analysis, and options are examined for reducing the error of each model with one or more user-fitted parameters. Parameter estimation is discussed for viscous, time-independent, non-Newtonian, laminar and turbulent flow models. Due to extensive requirements of the data analysis, the parameter estimation methods are robust, and generally suitable for any shear flow relation. The difficulties of estimating parameters of shear flow models from pipe flow data are addressed. Numerical algorithms are presented for modelling the flow of time-independent, non-Newtonian, viscous fluids through a straight pipe. Laminar, critical and turbulent flow algorithms are developed to offer predictions such as pressure gradient, mean cross-sectional velocity, and the velocity distribution. To handle the requirements of the data analysis, the algorithms impose few restrictions on the type of shear flow relation, the flow velocity, and the pipe diameter. Suitable pipe flow equations are chosen, and are manipulated mathematically into forms that would yield robust and efficient schemes. The appropriate use of numerical methods for the algorithms is investigated. Mathematical models of sludge are for use by the sewage industry to give an idea of the flow behaviour of sludges for any relevant application. The parameter estimation techniques and pipe flow algorithms are not constrained to any particular pipe, fluid or flow conditions, so they would be useful for any relevant application.

Demonstrou-se nesta tese a potencialidade da ressonância magnética nuclear no domínio do tempo (RMN-DT) para medir a temperatura de sementes oleaginosas isoladas e inseridas em solos. Os métodos desenvolvidos baseiam-se na correlação entre o tempo de relaxação do óleo das sementes com a temperatura. As medidas com o tempo de relaxação transversal, T2, foram realizadas com a sequência Carr-Purcell-Meiboom-Gill (CPMG) e as medidas de relaxação T*, com a sequência de pulsos Precessão Livre em Onda Contínua (CP-CWFP). Tanto o T2 quanto o T* apresentaram uma correlação exponencial crescente com a temperatura, utilizando espectrômetros de bancada. Com a medida do decaimento da temperatura de sementes e solos, previamente aquecidos a 70°C, em um banho térmico a 23°C, pode-se calcular a difusividade térmica de sementes e sementes em solos, obtendo valores similares aos obtidos com métodos padrões. Para ímãs com homogeneidade muito baixa, com gradientes de campo magnético maiores do que 1 T/m (ímãs de campos opostos, Unilateral e Halback) somente a sequência CPMG pode ser usada. A sequência CP-CWFP não gerou um sinal de onda contínua, necessário para a medida de T*. No ímã unilateral a correlação exponencial entre o decaimento do sinal CPMG e temperatura foi decrescente devido ao efeito da difusão molecular na refocalização dos ecos. Com isso a RMN unilateral, que detecta o sinal da amostra fora do sensor de RMN (ímã e sonda) tem potencial para análise da temperatura e difusividade térmica em campo. A grande vantagem da RMN sobre os métodos de termometria baseado em termômetros de mercúrio, termopares, termistores, etc., é que é um método que não precisa danificar as sementes para inserção do agente sensível à temperatura. Além disso, a RMN pode ser usada para medir a temperatura da semente, mesmo quando esta está sob uma camada de vários centímetros de solos, o que não ocorre com o sensor de Infravermelho, por exemplo. / The potential of time domain nuclear magnetic resonance (TD-NMR) to measure the temperature of isolated oilseeds and oilseeds inserted into soil was demonstrated in this thesis. The methods were based on the correlation between relaxation time of the oilseeds with temperature. The measurement with the transverse relaxation time, T2, was performed with the Carr - Purcell - Meiboom - Gill (CPMG) pulse sequence. The measurement of decay T*, was performed with the Continuous Wave Free Precession (CP- CWFP) pulse sequence. Both the T2 as T* showed an exponentially correlation with temperature using bench top spectrometers. With the measurement of the temperature decay of seeds and soils, previously heated to 70°C and placed in a bath at 23°C, was used to calculate the thermal diffusivity of seeds and seeds in soil. The results were similar to those obtained with standard methods. For the magnets with very low homogeneity, with strong magnetic field gradients 1 T/m (Opposite field, Unilateral and Halback magnets) only the CPMG pulse sequence could be used. The CP-CWFP sequence do not generated a continuous wave signal, necessary for the measurement of T*. The unilateral magnet shows an upward-sloping exponential curve between the decay of the CPMG signal and temperature due to the effect of molecular diffusion, in refocusing echoes. Therefore, the unilateral NMR, which detects the signal from the sample outside the NMR sensor (magnet and probe), has the potential to analyze the temperature and thermal diffusivity in the field. The big advantage of NMR over thermometry methods based on mercury thermometers, thermocouples, thermistors, etc., is that it is a method that does not need to damage the seeds for insertion of the sensor. In addition, NMR can be used to measure the seed temperature, even when it is under a layer of several centimeters of soil, which does not occur with the infrared sensor, for example.

The novelty of this research is that it investigates an on-site solution for the treatment of restaurant waste using a microwave generated plasma for pyrolysis and gasification. The developed system has been used to treat waste from a city centre fast food restaurant. The system was designed with the aim of reducing the amount of waste being sent to landfill by approximately 94%. The waste is mostly food based but also includes paper waste such as napkins. It was separated into three categories: mixed food, paper and fries. Samples of the mixed food and paper waste were analysed for chemical composition and calorific value. A 2.45GHz magnetron was used to supply 1kW of microwave power to a plasma cavity that had an argon flow rate of 1.5 litre per minute. The design of the microwave plasma cavity was performed using the simulation software, COMSOL. The cavity consists of a tapered waveguide section that is shorted at one end to produce a stationary wave with a large electric field at the gas nozzle. The field is strong enough to produce a self-striking argon plasma when the power is applied. Nitrogen was used to keep the plasma cavity clear of smoke, vapours and other hot gas. The best nitrogen flow rates were found to be around 2 litres/minute, although 5 litres/minute was used in the test to avoid the CO sensor saturating. The combination of the argon and nitrogen was used to purge the gasifier of oxygen. The pressure inside the gasifier was held at 200mbar during the experiments. The resulting plasma jet was used to produce syngas from the waste samples inside a thermally insulated, steel-walled reactor. Temperature profiles were recorded to find the best gas flow rates. 10g samples of the three waste categories were tested in triplicate and the results are presented. Syngas production was recorded using a Quintox gas analyser that measured CO, CO2 and O2. The data was captured every 10s during testing using a PC running a custom-built LabVIEW program. This program was also used to set the microwave output power and record the reflected power and temperatures using National Instruments cDAQ modules with analogue to digital converters. The CO and H2 in syngas can be used as a fuel to offset the cost of running the plasma jet. The results reveal that it is possible to generate the syngas using waste food materials. This study has included an investigation of some of the parameters, including power and flow rates of argon and nitrogen, on the plasma created. Others effects were taken into consideration throughout the research such as the study of the sample moisture levels and the final reduction of mass after the experiment. The ashes produced by the tests were investigated using SEM/EDX analysis. These results are also presented and analysed.