Performance monitoring is commonly portrayed as providing a uniquely objective, rational foundation for decisions, based on a single-stranded feedback loop between setting objectives and measuring results. In this thesis, I investigate whether this portrayal is accurate. I analyse whether the linear model underlying performance monitoring provides an adequate basis for understanding decisions about access to rural water supply in Ethiopia. My examination focuses primarily on the politics of knowledge production from three angles. First, I examine whether the assumptions underlying the definition of ‘access' to rural water used in performance monitoring in Ethiopia, adequately represent the divergent notions of access among the relevant actors. My findings show that formal framings of access, codified in national and international guidelines and benchmarks, focus on technical aspects of the water supply infrastructure. I bring to light that the goal of performance monitoring in relation to achieving ‘access' is driven by the methods used to measure it, mainly the parameters of infrastructure, volume, distance and quality, suggesting a circularity between framings of the inputs to and objectives of appraisal. In this self-referential process, a particular image of the world determines the meaning of performance, which is used as a yardstick. The power of this dynamic is apparent in Ethiopian stakeholders' characterisations of access, which, even when critical, revolve narrowly around these dominant parameters. This one-dimensional and technical framing of access, constantly reproduced in self-referential monitoring circles, contrasts starkly with the multi-dimensional and dynamic nature of the water access experiences of local residents in Ethiopia. Second, I test whether, in reality, monitoring processes conform to the linearity assumed by the feed-back function of performance monitoring. The process tracing method used to illuminate the political and power dynamics of monitoring processes, shows that sector government actors at different administrative levels, with different rationales, provide different stories of ‘access'. Viewed from this perspective, performance monitoring can be seen not, as conventionally asserted, as a uniquely rational appraisal of performance, but rather as being about ‘performing monitoring' – the playing out on a management stage of certain politically-necessary performances. At the same time, I find that numerous less formalised monitoring practices proceed in parallel with the formal PM process, which, together, form a body of largely ‘tacit' knowledge that informs sector stakeholders' daily work. It is this wider body of knowledge, rather than only formalised PM results, that informs decisions. Third, I investigate the mechanisms that led to the formulation of specific decisions associated with rural water access and the role in these of performance monitoring. I find that particular decisions, such as repairs to rural water schemes, have multiple causes, among which performance monitoring is a contributory and necessary, but not sufficient factor. My investigation of criteria affecting budget allocations highlights that sector offices' limited control over them contributes to making strategic planning a rubber stamping exercise whose processes can be characterised as ‘muddling through' as opposed to adhering to the linear model suggested by Results-based Management. My findings highlight the need to break the self-referential cycle of narrowly framed performance monitoring exercises. They suggest greater attention to the ‘tacit' monitoring practices in local settings, and a focus on the process of monitoring and the power relations within it, to complement the dominant focus on monitoring targets and indicators.

The shortage in water resources have been observed all over the world. However, the safety of drinking water has been given much attention by scientists because the disinfection will react with organic matters in drinking water to generate disinfection by-products (DBPs) which are considered as the cancerigenic matters. Although much research has been carried out on the water quality control problem in DWDS, the water quality model considered is linear with only chlorine dynamics. Compared to the linear water quality model, the nonlinear water quality model considers the interaction between chlorine and DBPs dynamics. The thesis proposes a nonlinear model predictive controller which utilises the newly derived nonlinear water quality model as a control alternative for controlling water quality. EPANET and EPANET-MSN are simulators utilised for modelling in the developed nonlinear MPC controller. Uncertainty is not considered in these simulators. This thesis proposes the bounded PPM in a form of multi-input multi-output to robustly bound parameters of chlorine and DBPs jointly and to robustly predict water quality control outputs for quality control purpose. The methodologies and algorithms developed in this thesis are verified by applying extended case studies to the example DWDS. The simulation results are presented and critically analysed.

Sand has been the main filter media used in rapid gravity filtration since their emergence in the 19th century. This dominance is due to its low cost, availability and extensive experience which has led to dependable and predictable performance. Over recent years multi-media filters have become the typical filter arrangement. Sand still remains the preferred filter medium in the lower layer with typically anthracite used in the upper layer. A limitation to match previous work has been the emphasis on overall performance but mechanistic analysis as to the reasons for the variations compared to sand has been rare. The fundamental effects of particle size and consolidation on filtration performance and headloss are known but were not often accounted for in the reported research. This has limited the academic contribution of previous work and made it more difficult to compare with the data for this thesis. At an average treatment works the highest costs are associated with the use of chemicals (30 %) and power (60 %) required mainly for pumping. Rapid gravity filters are one of the least energy demanding stages in this system, only requiring pumping for backwashing and air scour, assuming gravity feed was incorporated into the design. Energy efficiency of water treatment has become more important and the research was conducted to determine if the use of novel new media could be used to improve the performance of the filters with regards to turbidity and headloss. For example, the result presented within this thesis demonstrates through the use of angular media improved performance to benefit both turbidity and headloss performance. This was obtained from slate having a sphericity of 0.49 compared to sand at 0.88. In addition the use of novel materials with different physical properties has allowed an extension to analysis of performance using fundamental filtration mechanisms. The greater range of properties available from the novel media used in this thesis compared to sand has suggested additions to this theory. The use of surface reactive materials, including limestone, has shown the removal of additional contaminants such as phosphorus, iron, aluminium and manganese not typically associated with rapid gravity filtration. An assessment of the impact these reactions had on typical filter performance criteria, for example turbidity, headloss and life expectancy. The results showed an 97 % removal of Fe in the limestone compared to 13 % for sand. This was brought about by the precipitation of hydroxide, coagulation, a pH change and consequent co-precipitation. In the case of iron and aluminium removal this pH induced change was theorized as the most likely cause of coagulation within the filter bed itself leading to improved turbidity removal performance. Filter media chosen for laboratory and pilot study in this work was firstly assessed using British Standards tests, but additional tests were added that could provide additional characterisation data. The media were selected based on an individual fundamental property that differed from the other media selected whilst retaining the standard RGF size. Filtralite for example offered a high surface area, limestone a more active surface and slate a plate-like particle shape. Glass had a very smooth surface texture and as a recycled material better sustainability. Four of these filter media (Sand (control), Glass, Filtralite and Slate) were then selected for further on-site pilot plant studies, based on results from the laboratory work. Both the laboratory and pilot study suggested that turbidity and headloss performance could be improved by changes in media specification. The results showed that after particle size, angularity of the media was the most important factor affecting turbidity and headloss performance. A greater angularity led to improvements in filter run time with for example a doubling of filter run time with the slate compared to sand for the same turbidity removal in the pilot plant. Previous literature had suggested an improvement in turbidity performance but that head loss would deteriorate but this was not seen in the data from this research, with slate (sphericity of 0.49) offering improved headloss performance. This improvement was attributed to the varied packing of the filter bed and associated porosity variations throughout the filter. The objectives of the pilot study were to provide understanding of scale-up factors and adjust these theories with real variable clarified water. Real water chemistry is too complex to model and enabled experiments more typical of the variation that a rapid gravity filter would encounter. The pilot plant is 0.07 % the plan area of a full scale filter compared to the 0.01 % of the laboratory columns. Results corroborated the laboratory work on the effect of extreme particle shapes on filter performance. The pilot study also highlighted problems from floc carry over with the use of clarified water and quantified the impact it had on filtration performance. In this case floc carryover changed the performance of the pilot plant results significantly. Thus an overall conclusion from the work was that an integrated design approach to filters, to account for the clarifier type the likelihood of floc carryover and raw water anticipated could be further researched. There were also limitations to the current monitoring equipment that could not quantitatively measure the floc carryover because of large particle size.

Aquifer Storage and Recovery (ASR) involves the injection of water into an aquifer for subsequent recovery from the same well. Whilst ASR provides a competitive alternative to reservoir storage, a lack of precedence of successful schemes and uncertainties with respect to regulatory requirements, and abstracted water quality and quantity have limited its implementation in the UK. The ambition of this research is to improve understanding of these impediments with particular reference to the Sherwood Sandstone aquifer. Drawing on existing project review and risk management approaches, a decision support tool to help scheme designers scope ASR scheme potential and challenges was developed and tested. The tool provides practitioners with a systematic method for early stage evaluation of ASR schemes with testing confirming broad value and alignment with business processes. Limitations on the recovery of recharged water was investigated through a critical literature review on clogging with geochemical, biological, physical and gaseous binding processes identified as the most likely mechanisms to impact an ASR scheme in this aquifer. Water quality changes during storage and the impact of storage period on recovered water quality were investigated in the laboratory using ASR simulating columns, with storage times of 15, 20, 30 and 60 days. Water quality improvements such as biodegradation of disinfection by-products, denitrification and sulphate reduction were observed. However recovered water quality deteriorated with respect to iron, arsenic, manganese, total organic carbon and nickel. These results, together with the review of regulations conducted as part of decision support tool development, suggest that the current interpretation of the Water Framework Directive requirements is overly restrictive and is deterring wider implementation of ASR in the UK. Conclusions focus on the need for a more appropriate approach to regulating ASR schemes, in particular, one which adopts a risk based approach to determining water quality standards.

This thesis reports on the research undertaken to reduce the water usage within manufacturing through modelling and improving the water efficiencies at both process and production system levels. The primary objectives of this research are: to develop a framework which classifies the various water usages within a manufacturing facility, to define a number of efficiency ratios to highlight the water inefficient activities, and to develop a decision support tool to aid with the selection of the most effective solutions for reduction of water usage within manufacturing applications. The research undertaken in the past three years is divided into four main parts. The first part reviews the relevant literature on water availability and distribution, the role of water in manufacturing, and relevant legislations and policies governing the water usage in manufacturing industries. The review also includes assessment of current water flow modelling and wastewater management tools and technologies. The second part introduces a Manufacturing Water Usage framework which classifies the water usage within a manufacturing facility as production-related and non-production-related water. The Production Water, which is the main focus of this research, is further classified as Process and System Water required to produce a product. Process Water is defined as the water used directly by the production processes, whereas System Water is defined as the water used to support the operation of a process and/or to maintain the production equipment. The framework also incorporates the definition of a number of Water Efficiency Ratios to determine the water critical processes. The third part of the thesis describes the implementation of this framework within a water simulation model as the main engine for a water reduction decision support tool. The final part of the thesis demonstrates the utilisation of this tool to support the decisions aimed at reducing water within a real food production line. In summary, the research has concluded that the consideration of water reduction scenarios within the manufacturing industry requires a detailed understanding of where and how water is used at production process level, and utilisation of this knowledge to develop a series of proactive approaches based on product/process redesign and radical operational planning improvements.

In recent years, the increasing awareness of scarcity of water resources, indications of likely climate variability, and the increasing pressure to use available fresh water resources more efficiently have together reinforced the need to look at infrastructure solutions with due regard to environmental considerations and social impacts, present and future. There is a vital need to apply an integrated approach to catchment management to implement sustainable solutions to resolve issues such as water supply and sewerage, drainage and river flooding. Many potentials solutions are available to control water demand and manage flood problems. Greywater recycling and rainwater harvesting are novel technologies. However, their catchment scale impacts on hydraulic and hydrological flows are poorly understood. The research aim is to identify the hydrologic and hydraulic impacts of scaling up such technologies at catchment scale. For this particular study, a computer simulation model will be used to evaluate how increasing urbanisation, climate change and the implementation of greywater recycling and rainwater harvesting may alter the water balance within a representative catchment. To achieve these aims data from the Carrickmines catchment in Ireland have been collected; a simulation model has been adapted to carry out the study, the model has been calibrated and validated, results have been analysed, and finally, a sensitivity analysis has been carried out. The results show that rainwater harvesting systems are comparatively more effective than greywater recycling techniques in reducing flood frequency and intensity. Under five year return period rainfall events, the implementation of rainwater harvesting at any scale and number of units is a useful technique to control river flow and floods. However, the study also shows that under extreme conditions the efficiency of rainwater harvesting systems decreases. The study concludes that implementing the two technologies within a single catchment is not a solution to several forms of hydrological problem. The study shows that implementing rainwater harvesting or re-use technologies are a very useful way to protect local freshwater reserves and therefore conserve our environment.

The world’s growing population is causing an ever increasing demand for clean safe drinking water. In some countries suitable sources of drinking water are becoming scarce and will not be able to satisfy future demand. Consequently, there is a need to find alternative sources of water that can be used for potable supply or to augment current sources. Advanced water treatment methods are now being examined to investigate whether treated domestic sewage effluent can be treated to drinking water standards and discharged upstream of a drinking water abstraction point; a process known as Indirect Potable Reuse (IPR). The aim of this project was to investigate biological activity associated with developmental exposure to IPR water at the various stages of treatment using zebrafish embryos. Embryos reared in water at different stages of the treatment process were observed for developmental abnormalities, and differences in gene expression (compared to an aquarium water control) were used to establish both the nature and persistence of these effects along the treatment process. In addition to the embryo assays, passive sampling devices, Pharmaceutical Polar Organic Integrative Sampler (Pharm-POCIS) were deployed over eight, four week periods to collect composite concentrated samples of some of the contaminants present in the effluent. These concentrated extracts were then used in an in vitro assay; an Enzyme Immunoassay (EIA) to measure the inhibition of prostaglandins (an indirect measure of inhibitors of cyclooxygenase activity). We compared our results of the bioassays with the large body of chemical analysis data recorded over a number of years from each of the treatments. The developmental exposures highlighted a low frequency of consistent abnormalities to the heart and spine, and also a lack of pigmentation. Gene expression analysis demonstrates the developmental stage of the embryo to have the greatest influence on global gene expression as opposed to the treatment. Single genes of interest included the two cytochrome P450s (cyp1a and cyp1b1) and somatolactin beta. Some of the pathways disrupted included steroid synthesis, retinol metabolism, tryptophan metabolism and melanogenesis. The latter was consistent with observations of some embryos devoid of pigment. Along the treatment process reverse osmosis seemed to cause the largest change to the gene expression. The extracts from less treated effluent inhibited prostaglandin production, however following reverse osmosis prostaglandin inhibition was greatly reduced. The chemical contaminantion is greatly reduced as the effluent progresses along the IPR treatment process, this is evident from both the chemical data and the biological assays. Reverse osmosis seems to have the greatest influence on the gene expression. The results have highlighted the importance of an appropriate control, to remove background noise.

Membrane technology can be utilised for the high purification and desalination of water. However membrane filtration processes are commonly impeded by membrane fouling, which can lead to flux decline and an overall reduction in separation efficiency within the process. Therefore the aim of this research study was a comprehensive investigation of the issue of biofouling on industrial RO membranes through molecular biology techniques, characterisation of surface charge of foulant bacteria and RO membrane surface and AFM imaging and force measurements on clean and fouled membranes for the determination of adhesion force and micromechanical properties. The laboratories within Gwangju Institute of Science and Technology, South Korea and Swansea University, Wales were equipped for the scope of this research work. Research focused on the extraction of microbial DNA obtained from fouling layers on the surface of Reverse Osmosis Membranes obtained from the Fujairah Water and Power Plant, UAE. The use of the culture independent method of the molecular technique based on the 16S rDNA sequence and constructed gene libraries, was then used to determine the bacterial species that caused significant fouling on the RO membrane. Four bacterial species isolated from the fouling layer from the RO membrane were characterised in terms of electrophoretic mobility and zeta potential to determine the cell surface charge within various industrial relevant environments for the elucidation of cell adhesion mechanisms to the membrane surface. AFM images of virgin and fouled membranes were obtained and analysed to reveal the roughness of the surface which could influence fouling and the surface charge of the membranes were measured through the method of streaming potential at various industrial relevant environments to further elucidate the mechanisms of cell adhesion to the membrane surface. Force measurements were performed to reveal the adhesion force and elasticity values of virgin, process fouled and purposely fouled with the four bacterial isolates, to determine process behaviour in various environmental conditions. Through this research and future work, it is hoped that a rational strategy for economic and effective cleaning processes will be developed which will maintain efficient membrane operation and prolong membrane life, thus enabling the reduction of operating costs of such processes.

No description available.

L'hydrogène pourrait jouer un rôle prépondérant dans le domaine de l'énergie dans les années à venir. De nos jours, la production d'hydrogène provient majoritairement de ressources fossiles. En vue de l'impact néfaste de l'utilisation de ressources fossiles sur l'environnement, produire de l'hydrogène à partir de ressources renouvelables présente un grand intérêt. Dans cette étude, le reformage autotherme du biogaz, une source renouvelable de méthane, a été étudié sur des catalyseurs au nickel à 700°C et à pression atmosphérique. Cette étude porte sur un biogaz modèle composé à 60% de méthane et 40% de dioxyde de carbone mis en présence d'oxygène et de vapeur d'eau dans les proportions : 42% H2O, 14% CH4, 9% CO2, 7% O2 dilués dans l'argon. Dans un premier temps, un criblage de catalyseurs au nickel a été réalisé grâce à un montage composé de 6 réacteurs parallèles. L'outil a permis de montrer qu'un catalyseur bimétallique NiRh supporté sur un spinelle de magnésium était actif et très stable, montrant une conversion totale du méthane après 200h de réaction. L'équivalent de ce catalyseur sans Rh s'est désactivé après seulement 2h de réaction. Notre étude a démontré que cette désactivation était causée par la formation du spinelle de nickel, NiAl2O4. Cette formation est une conséquence des hautes températures présentes dans la zone de combustion qui induisent un désordre dans la structure cristalline du support et permettent, en présence de NiO, la diffusion de ions Ni2+ dans les lacunes du support. Enfin, une étude cinétique a été menée sur des catalyseurs structurés. Un modèle cinétique a été développé, permettant également de décrire le profil de désactivation causée par la perte de sites actifs / Hydrogen is expected to play an increasingly important role in the energy sector in the years to come. Nowadays, hydrogen is mainly produced from fossil fuels. The extensive use of fossil fuels is unsustainable and therefore, hydrogen production from renewable sources is of great interests. Autothermal reforming of biogas, a renewable source of methane, was studied over nickel catalysts at 700°C and at atmospheric pressure. This study focused on model biogas composed of 60% methane and 40% carbon dioxide, reacting with oxygen and steam respecting the composition: 42% H2O, 14% CH4, 9% CO2, 7% O2 diluted in argon. First and foremost, a screening of different catalyst compositions was carried out with a six parallel-flow reactor set-up. This high-throughput technology showed that a NiRh bimetallic catalyst supported on magnesium spinel was active and very stable, still fully converting methane after 200 hours of reaction. On the other hand, its noble-metal free equivalent deactivated after only 2 hours. Our study showed that deactivation was caused by the formation of nickel spinel NiAl2O4. Its formation is a consequence of the exothermicity of the combustion reaction taking place at the catalyst inlet. The high temperatures induce a disorder in the crystal structure of the support and, in presence of NiO, Ni2+ ions can then diffuse into the vacancies of the support. The inactive NiAl2O4 phase is formed. Finally, a kinetic study was performed on structured catalysts. A kinetic model was developed, which also allowed the description of the deactivation profile caused by the loss of active sites