Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2006. / Includes bibliographical references (leaves 42-46). Also available in electronic version.

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: Conductivity, pH, Dissolved Oxygen, UV absorbance, Source Water, Surface Water, Dissolved Organic Carbon, Total Organic Carbon, Particle Counts, Turbidity, E. coli, Fecal Coliforms, West Boylston Brook, Wachusett Reservoir, source water protection, surface water protection Includes bibliographical references (p.73-77).

Thesis (Ph.D.) - University of Queensland, 2005. / Includes bibliography.

Thesis (M. Sc.)--University of Hong Kong, 2006.

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

A slow sand filter system was developed which was suitable both for experimental purposes and full scale community water supply. The performance of the system was enhanced by the incorporation of pretreatments such as gravel prefiltration, sub-sand prefiltration and direct protection of filters by the incorporation of synthetic fabric layers. The system was used to examine aspects of the biological and physico-chemical nature of Slow Sand Filtration with particular reference to the removal of Rotavirus and a variety of bacterial and viral indicators. The results of the developmental phase and experiments conducted with operational filters and in the laboratory confirmed the importance of biological mechanisms, in particular adsorption to biological surfaces present in the upper horizons of slow sand filters. It was observed that both the efficiency and pattern of removal of Rotavirus in Slow Sand Filtration were similar to those observed for faecal indicator bacteria, bacteriophage and turbidity ie colloidal clay and other particles. Thus it was concluded that negatively charged particulate colloidal entities appear to behave similarly despite differences in size and surface characteristics and that Rotavirus is no more or less likely to pass through slow sand filters than any other particle. Thus, a well operated slow sand filter may be expected to achieve a reduction in Rotavirus densities of 2 log10 orders of magnitude. The principal mechanisms of removal of Rotavirus in the upper horizons would appear to be transportation by diffusion and adsorption to biofilms and biomass. Microbial predation is not likely to play a dominant role in the removal of Rotavirus from the aqueous phase but may be important in inactivation. A detailed examination of the incidence, prevalence and seasonal occurrence of rotaviral and other diarrhoeas in less developed countries led to the observation that unlike some of the bacterial pathogens, transmission of Rotavirus does not have a strong association with water quality. Hence. The case for low level waterborne transmission and thereby maintenance of endemicity in the community remains entirely theoretical. Moreover, bearing in mind the likelihood that slow sand filters will be operated sub-optimally in many cases, a moderate reduction in Rotavirus densities eg 1 - 2 log10 units may not be significant in terms of diarrhoeal disease risk, particularly for children and especially in the rural sector. In view of these observations and other factors eg the low infective dose of the virus and the undoubted pre-eminence of person-to-person spread, it was concluded that as a single process, Slow Sand Filtration is probably not capable of significantly reducing the incidence of rotaviral diarrhoea in less developed countries.

Please read the abstract in the section 00front of this document / Thesis (PhD (Water Utilisation))--University of Pretoria, 2005. / Civil Engineering / unrestricted

The economy of not only British Columbia but, according to recent water-diversion proposals, much of western North America is dependent on the water resources of British Columbia. Because of its importance, the water resources of the province must be managed properly, requiring information on the amount of the resource, its spatial and temporal distribution, and how these factors may be influenced. Research has shown that forest management influences the yield, regime, and quality of water. A comprehensive review of such research was presented and related to watershed management in British Columbia. Legislation, administration, and problems of water management were discussed with particular reference to forest management. It was recommended that B.C. Forest Service field staff be increased and that watershed management receive greater emphasis at the Forest Service Training School, Institute of Technology, and the University of British Columbia. The division of jurisdiction between the federal and provincial governments was suggested as the reason for the passive role of the federal government in water resources. Because Canada’s present water administration is inadequate for the future, the federal government should assume responsibility for initiating action on water-resource development, and the provinces should be willing to forego some degree of provincial rights in the interest of comprehensive management of the resource. The water resources of the province were examined and four watershed- management regions were designated (Coastal, Peace River, Interior, and Columbia Mountains) on the basis of climatic factors, water needs, and flood and erosion potential. Forest-management was related to the objectives of watershed management in each region. One objective of watershed management in the Interior Region is increasing water supplies. Tree Farm License No. 9, in the Okanagan Valley was used to demonstrate forest-management effects on water yield. Yield could be increased five per cent by substituting for the present forest management one based on financial rotations and consideration of water as an important secondary product. Statistical calibration of Windermere and Sinclair Greeks in the East Kootenays was presented, and the effect of logging on streamflow from Watching Greek near Kamloops was analysed graphically. Water balance and other studies were presented for Terrace Greek watershed on Tree Farm License No. 9. Other watershed research in British Columbia was reviewed and research needs discussed. A comprehensive research program was recommended, to begin with intensely-instrumented research watersheds in the Coastal and Interior Regions. A rational mathematical rainfall-interception model was developed using forest-stand variables, most of which can be measured on aerial photos, and data from interception studies carried out in British Columbia and the United States. / Forestry, Faculty of / Graduate

Mr. R.A. Pullen

The contents of this thesis deal with the complete design of a water supply system for a typical small-sized teeming modern Chinese city with a population of about 30,000. A fictitious map of the city with contour lines and all the necessary details was prepared for this purpose. The factors of construction, distribution and sanitary aspects are considered in the design. Theories and methods are fully explained whenever seems advisable.