Eighty percent of the 780 million people worldwide that access water from an unimproved source live in rural areas. In rural areas, water systems are often managed by community based organizations and many of these systems do not provide service at the designed levels. The Sustainability Analysis Tool developed in Chapter 2 can inform decision making, characterize specific needs of rural communities in the management of their water systems, and identify weaknesses in training regimes or support mechanisms. The framework was tested on 61 statistically representative geographically stratified sample communities with rural water systems in the Dominican Republic. The results demonstrated the impact that long term support by outside groups to support community management activities can improve sustainability indicators, including financial sustainability which is a significant issue throughout the world. When analyzing the financial sustainability of water systems, it is important to consider all life-cycle costs including the expenditures made by households. Chapter 3 analyzes financial and economic expenditures on water services in 9 rural and peri-urban communities in Burkina Faso. Data from household and water point surveys were used to determine: socio-economic status, financial and economic expenditures, and service levels received by each household. In Burkina Faso recurrent financial and economic expenditures on water service ranged between US$5 and US$9.5 per person per year, with cumulative costs approximately US$19.5 per person per year. The average expenditures on water in Burkina Faso were well above the affordability threshold used by World Bank demonstrating the need to improve subsidies in the water sector. The sustainability of water supply systems and the ability to ensure the health benefits of these systems is also influenced by the deficiencies in sanitation infrastructure. Unimproved sanitation can be a source of water contamination and a risk factor in water related disease. Furthermore, the effective management of community water supply infrastructure is not a sufficient condition for ensuring water quality and eliminating health risks to consumers. As a result water treatment technologies, such as ceramic water filters (CWFs), implemented and managed at the household level and combined with safe storage practices are proposed as a means of reducing these risks. The performance of CWFs in laboratory settings has differed significantly from field studies with regard to microbial treatment efficacy and also hydraulic efficiency. Chapter 4 presents a 14 month field study of two locally manufactured CWFs conducted in a rural community in the Dominican Republic. Each of the 59 households in the community received one filter. The CWFs in this study performed poorly with regard to water quality and hydraulic performance. Focus group meetings and household survey suggests that flow rate is a major issue for user acceptability. To address the user concerns Chapter 5 presents two mathematical models for improving the hydraulic performance for the frustum and paraboloid designs. The models can be used to predict how changes in user behavior or filter geometry affects the volume of water produced and therefore can be used as tools to help optimize filter performance.

No description available.

Arsenic-based pesticide residues have been detected on Arizona State Museum’s (ASM) Diné (Navajo) textile collection using a handheld portable X-ray (pXRF) spectrometer. The removal of this toxic pesticide from historic textiles in museums and collections is necessary to reduce potential health risks to Native American communities, museum professionals, and visitors to these cultural institutions. A leader in engineering innovative pesticide removal methods, ASM received federal funding support to continue essential research in removing heavy metal pesticides from cultural property. The research objective was divided into three interconnected stages: (1) calibrate the pXRF instrument for arsenic contaminated cotton and wool textiles; (2) engineer a textile conservation aqueous washing treatment to remove arsenic from wool textiles; (3) demonstrate the aqueous washing treatment method on actual Navajo textiles known to have arsenic-based pesticide residues. The calibration process consisted of a dipping method to produce known homogenous arsenic cotton and wool test samples saturated with solutions of 100, 500, 1000, 2500, and 5000 parts per million (ppm). A linear correlation between observed pXRF test readings and formulated arsenic solutions corroborated the instruments range of detection for arsenic on specific textile materials. The calibration confirms that the pXRF is suitable instrument to measure the removal of arsenic from wool textiles. Wool test samples treated with solutions of an arsenic concentration of 1000ppm were used to develop an optimal aqueous washing treatment exploring the effects of time, temperature, agitation, and pH conditions to efficiently remove arsenic while minimizing damage to the structure and properties of the textile. Each conditional effect removed a certain percentage of arsenic, although the most efficient aqueous washing treatment consisted of submerging a wool textile in deionized water at room temperature for ten minutes with the greatest level of agitation within reason to minimize damage the textile. The final stage of the research applied the aqueous washing guidelines formulated from experimental research on three historic ASM Navajo textiles. Two textiles contained low arsenic concentrations (<100ppm), and one tested with a high arsenic concentration (~1000ppm). The aqueous washing treatment resulted in minimal change for low arsenic concentration textiles, and a 96% removal of arsenic on a high arsenic concentration textile. The preliminary success of removing arsenic-based pesticide residues from historic Navajo textiles greatly impacts the future management of historic textile collections, and also raises questions to further refine the research methodology or pursue alternative related research such as engineering a closed circulating arsenic removal system to limit the quantity of toxic water.

The research described in the thesis details the investigation of build-up and wash-off process kinetics of Polycyclic Aromatic Hydrocarbons (PAHs) and heavy metals in urban areas. It also discusses the design and development of a rainfall simulator as an important research tool to ensure homogeneity and reduce the large number of variables that are usually inherent to urban water quality research. The rainfall simulator was used to collect runoff samples from three study areas, each with different land uses. The study areas consisted of sites with typical residential, industrial and commercial characteristics in the region. Build-up and wash-off samples were collected at each of the three sites. The collected samples were analysed for a number of chemical and physico-chemical parameters. In addition to this, eight heavy metal elements and 16 priority listed PAHs were analysed in five different particle size fractions of the build-up and wash-off samples. The data generated from the testing of the samples were evaluated using multivariate analysis, which reduced the complexity involved in determining the relative importance of a single parameter in urban water quality. Consequently, variables and processes influencing loadings and concentrations of PAHs and heavy metals in urban stormwater runoff from paved surfaces at any given time were identified and quantified using Principal Component Analysis (PCA). Furthermore, the process kinetics found were validated using a multivariate modelling approach and Partial Least Square (PLS) regression, which confirmed the transferability of chemical processes in urban water quality. Fine particles were dominant in both the build-up and wash-off samples from the three sites. This was mirrored in the heavy metal and PAH concentrations at the three sites, which were significantly higher in particles between 0.45-75μm than in any other fraction. Thus, the larger surface area and electrostatic charge of fine particles were favourable in sorbing PAHs and heavy metals. However, factors such as soil composition, total organic carbon (TOC), the presence of Fe and Mn-oxides and pH of the stormwater were all found to be important in partitioning of the metals and PAHs into different fractions. Additionally, PAHs were consistently found in concentrations above their aqueous solubility, which was attributed to colloidal organic particles being able to increase the dissolved fraction of PAHs. Hence, chemical and physico-chemical parameters played a significant role in the distribution of PAHs and heavy metals in urban stormwater. More importantly, the research showed the wide range of factors that distribute metals and PAHs in an urban environment. Furthermore, it indicated the need for monitoring these parameters in urban areas to ensure that urban stormwater management measures are effective in improving water quality. The build-up and wash-off process kinetics identified using PCA at the respective land uses were predicted using PLS and it was found that the transferability of the governing processes were high even though the PAHs and metal concentrations and loads were highly influenced by the source strength at each site. The increased transferability of fundamental concepts in urban water quality could have significant implications in urban stormwater management. This is primarily attributed to common urban water quality mitigation strategies relying on studies based on physical concepts and processes derived from water quantity studies, which are difficult to transfer between catchments. Hence, a more holistic approach incorporating chemical processes compared to the current piecemeal solutions could significantly improve the protection of key environmental values in a region. Furthermore, urban water quantity mitigation measures are generally designed to reduce the impacts of high-flow events. This research suggests that fairly frequent occurring rainfall events, such as 1-year design rainfall events, could carry significant heavy metal and PAH concentrations in both particulate and dissolved fractions. Hence, structural measures, designed to decrease quantity and quality impact on receiving waters during 10 or 20-year Average Recurrence Interval (ARI) events could be inefficient in removing the majority of PAHs and heavy metals being washed off during more frequent events. The understanding of physical and chemical processes in urban stormwater management could potentially lead to significant improvements in pollutant removal techniques which in turn could lead to significant socio-economic advantages. This project can serve as a baseline study for urban water quality investigations in terms of adopting new methodology and data analysis.

Accurate and reliable estimations are the most important factors for the development of efficient stormwater pollutant mitigation strategies. Modelling is the primary tool used for such estimations. The general architecture of typical modelling approaches is to replicate pollutant processes along with hydrologic processes on catchment surfaces. However, due to the lack of understanding of these pollutant processes and the underlying physical parameters, the estimations are subjected to gross errors. Furthermore, the essential requirement of model calibration leads to significant data and resource requirements. This underlines the necessity for simplified and robust stormwater pollutant estimation procedures. The research described in this thesis primarily details the extensive knowledge developed on pollutant build-up and wash-off processes. Knowledge on both build-up and wash-off were generated by in-depth field investigations conducted on residential road and roof surfaces. Additionally, the research describes the use of a rainfall simulator as a tool in urban water quality research. The rainfall simulator was used to collect runoff samples from small-plot surfaces. The use of a rainfall simulator reduced the number of variables which are common to pollutant wash-off. Pollutant build-up on road and roof surfaces was found to be rapid during the initial time period and the rate reduced when the antecedent dry days increase becoming asymptote to a constant value. However, build-up on roofs was gradual when compared to road surfaces where the build-up on the first two days was 66% of the total build-up. Though the variations were different, it was possible to develop a common replication equation in the form of a power function for build-up for the two surface types with a as a multiplication coefficient and b as a power coefficient. However, the values for the two build-up equation coefficients, a, and b were different in each case. It was understood that the power coefficient b varies only with the surface type. The multiplication coefficient varies with a range of parameters including land-use and traffic volume. Additionally, the build-up observed on road surfaces was highly dynamic. It was found that pollutant re-distribution occurs with finer particles being removed from the surface thus allowing coarser particles to build up. This process results in changes to the particle size composition of build-up. However, little evidence was noted of re-distribution of pollutants on roof surfaces. Furthermore, the particulate pollutants in both road and roof surfaces were high in adsorption capacity. More than 50% of the road and more than 60% of the roof surface particulates were finer than 100 μm which increases the capacity to adsorb other pollutants such as heavy metals and hydrocarbons. In addition, the samples contained a significant amount of DOC which would enhance the solubility of other pollutants. The wash-off investigations on road and roof surfaces showed a high concentration of solid pollutants during the initial part of events. This confirmed the occurrence of the 'first flush' phenomenon. The observed wash-off patterns for road and roof surfaces were able to be mathematically replicated using an exponential equation. The exponential equation proposed is a modified version of an equation proposed in past research. The modification was primarily in terms of an additional parameter referred to as the 'capacity factor' (CF). CF defines the rainfall's ability to mobilise solid pollutants from a given surface. It was noted that CF varies with rainfall intensity, particle size distribution and surface characteristics. Additional to the mathematical replication of wash-off, analysis further focused on understanding the physical processes governing wash-off. For this, both particle size distribution and physicochemical parameters of wash-off pollutants were analysed. It was noted that there is little variation in the particle size distribution of particulates in wash-off with rainfall intensity and duration. This suggested that particle size is not an influential parameter in wash-off. It is hypothesised that the particulate density and adhesion to road surfaces are the primary criteria that govern wash-off. Additionally, significantly high pollutant contribution from roof surfaces was noted. This justifies the significance of roof surfaces as an urban pollutant source particularly in the case of first flush. This dissertation further describes a procedure to translate the knowledge created on pollutant build-up and wash-off processes using small-plots to urban catchment scale. This leads to a simple and robust urban water quality estimation tool. Due to its basic architecture, the estimation tool is referred to as a 'translation procedure'. It is designed to operate without a calibration process which would require a large amount of data. This is done by using the pollutant nature of the catchment in terms of buildup and wash-off processes as the basis of measurements. Therefore, the translation procedure is an extension of the current estimation techniques which are typically complex and resource consuming. The use of a translation procedure is simple and based on the graphical estimation of parameters and tabular form of calculations. The translation procedure developed is particularly accurate in estimating water quality in the initial part of runoff events.

Thesis (M.E.S.)--The Evergreen State College, 2007. / Title from title screen (viewed 1/24/2008). "MES thesis." Includes bibliographical references (p. 51-54).

Thesis (D. Min.)--Abilene Christian University, 1996. / Includes abstract. Includes bibliographical references (leaves 221-229).

Thesis (Ph. D.)--Oregon State University, 2008. / Printout. Includes bibliographical references (leaves 138-151). Also available on the World Wide Web.

Thesis (Ph. D.)--University of Washington, 2008. / Vita. Includes bibliographical references (leaves 174-185).

Thesis (D. Min.)--Abilene Christian University, 1996. / Includes abstract. Includes bibliographical references (leaves 221-229).