Point source controls have been the primary methodology utilized to reduce pollutant loads into the waterways of the United States for the last 30 years. However, the complex dynamics that occur in the water column, in conjunction with increased amounts of urbanization in our watersheds, have made point source controls alone inadequate for solving our nation’s water quality problems. In order to determine the impacts that various water quality management strategies will have on water quality, dynamic models capable of simulating the complex interactions in both the water column and the watershed are necessary. The Blackstone River Water Quality Study was implemented to determine the impact of ongoing and proposed upgrades at wastewater treatment plants on water quality along the Blackstone River and the magnitude of corresponding reductions in pollutant loads into Narragansett Bay. The impacts of changes in land use in the surrounding watershed on water quality in the Blackstone were also analyzed as part of the study. The study utilizes an HSPF hydrologic model developed for the Blackstone River by the USGS. UMass and CDM then added water quality simulation capabilities to the model as well as discretizing the mainstem and extending its simulation period. The model continuously simulates water quantity and quality across 100+ reaches used to model the Blackstone River watershed for the period from 1996-2007. As part of the study, the construction, calibration and error bound of the model are detailed as well. Based on the results of model simulations, it is shown that improvements in instream water quality as well as decreases in the downstream pollutant transport are achieved through ongoing and proposed point source control strategies. However, it has also been shown that non-point source controls can also achieve the same instream improvement and pollutant reduction as the proposed point source controls in the watershed. Despite the significant improvements in water quality observed during the model simulations, none of the pollution reduction strategies, including the removal of all point source loads from the system allow the Blackstone River to achieve ambient water quality standards as recommended by the U.S. Environmental Protection Agency.

Because of the endangerment of life of the human beings due to the environmental pollution, a serious study of the pollution of the environment is most vital. Because of increasing surface water pollution there is great hazard of ground water pollution. About half the United States of America derives drinking water from aquifers and much of the projected demand is expected to be met from subsurface sources. Therefore, a study was needed to determine the process of ground water contamination due to nutrients, especially Nitrogen, its degree and Length and Time of Travel and factors inhibiting its flow through soil. The present study was undertaken at the 'Pine Crest Duck Farm' at Sterling, Massachusetts, where the nature of the soil was Gravely Sandy Loam and Three unlined (from the side and bottom) waste stabilization ponds existed and there was a great danger of ground water contamination due to Nitrogen in the vicinity of ponds and further. In the field, observation wells were installed along the redial line and bi-monthly samples of water were taken to monitor the levels of B.O.D., Ammonium, Nitrate and Nitrite Nitrogen. Since the Adsorption of the Nitrogen by the soil is great inhibitor in the movement of the Nitrogen through soil profiles, this study was undertaken to study the adsorptive capacity of the soil in 'Bench Tests' and to test the applicability and validity of various adsorption isotherms of nitrogen in the soil; to develop a dimensional model or prediction equation for the nitrogen in the soil under natural flow conditions by studying the effects of varying concentration and flow rates on the adsorptive capacity of the soil, based on the principles of similitude; to correlate adsorption values in bench and column tests; and to determine the length and time of travel of nitrogen through soil. The soil from the Farm was obtained from a depth of six feet with enough care so that original structure was maintained. Adsorptive capacity of the soil was determined through series of 'Bench Tests' and 'Soil Adsorption Columns' in the laboratory under temperature controlled chambers. From the Bench Tests Adsorption values of the soil at various concentrations of Ammonium, Nitrate and Nitrite Nitrogen were determined and validity and applicability of Adsorption isotherms were confirmed. To study the Adsorption Process under natural flow conditions 'Soil Adsorption Column Tests' were done by using never done before Dimensional Model Analysis of Factors affecting Adsorption and getting dimensionless numbers and further obtaining 'Break Through Curves' at different Concentration and flow rates and Adsorption Values were obtained for Ammonium Nitrogen and Nitrite Nitrogen. Finally, Component and Prediction Equations were obtained for Ammonium Nitrogen and Nitrate Nitrogen. By knowing the Adsorption Values of the soil Length and Time of Travel of Ammonium and Nitrate Nitrogen through soil was calculated at various Concentration Levels. A mathematical Prediction Equation was also obtained between Bench and Column Tests and Length of Time of Travel, t predict the adsorption values under natural flow conditions by just performing less time consuming Bench Tests. It was also found that under equilibrium Bench Test conditions and natural flow conditions, adsorption of Ammonium, Nitrate and Nitrite Nitrogen increased with increasing solution concentration and adsorption of Ammonium Nitrogen was considerably higher than Nitrate and Nitrite Nitrogen. It was further found that for solution concentrations of 20, 40, 60, 80 and 100 mg/l Ammonium Nitrogen and nitrate nitrogen will travel one foot distance in 183 and 115 days; 168 and 111 days; 148 and 98 days; 145 and 81 days; 130 and 98 days; and 127 and 97 days respectively. It was determined that at the present time contamination of shallow water wells does not pose Nitrogen contamination problem and installation of these wells beyond 300 feet radial distance from the waste stabilization ponds was safe.

The limited underground water resources and the dramatic increase of fresh water consumption in Qatar forced the government to seek alternative ways to compensate for the lack of fresh water resources. Unfortunately, most of the currently available alternatives are costly in terms of excessive fuel consumption; also they require large capital investment and high maintenance cost. Such plants currently produce over 98% of the total fresh water in Qatar. This ratio may increase to 100% in the next few years. The main aim of this work is to investigate the most viable water desalination processes, which can produce sufficient, and a continuous supply of fresh water with low operation and construction costs. Climatic conditions and solar radiation in Qatar have been studied and analysed to determine the performance of any potential solar system applicable to this country. A technical and economical investigation into the current and common desalination methods with particular emphasis on the three main desalination systems including multistage flash, multiple effect distillation and reverse osmosis were conducted and included. A comprehensive literature survey on various water desalination methods was undertaken. The current experimental program was confined mainly to one novel type of tilted tray solar still system, namely pyramid tilted tray solar still, which was developed to increase productivity by increasing the receiving surface area of the still (the absorber) in order to collect the optimum amount of solar radiation. Two types of cover have also been selected and tested in this work, namely pyramid and dome shapes. These tilted tray solar stills were designed and constructed on a small scale and have been tested under controlled laboratory conditions at the University of Hertfordshire. Various parameters, which are likely to effect the still performance have been investigated. These include water flow rate, spacing between cover and tray surface, glass thickness, insulation layer, and inlet water temperature. Finally, a comparison of the stills performance characteristics of the two shapes has been carried out. The laboratory experimental results of hourly production revealed that pyramid type solar still yield higher distilled water output results than the dome type. However, the use of the pyramid shape with tilted tray solar can lead to further increase in the still productivity by optimising the orientation and surface area of the still absorber. The field experimental results of pyramid solar still, which were conducted under local climate conditions of Qatar, indicated clearly that solar desalination can be a suitable economical option, particularly for remote areas, where the fresh water demand is low and water transport is expensive. Moreover, a theoretical model was employed to predict the effects on solar still performance under three various parameters under typical climatic conditions of Qatar; These include the thermal insulation layer, the water depth and wind speed. Due to the economical reasons the dual-purpose multistage flash process will remain for the foreseeable future the preferred process, when fresh water and electricity demands are growing concurrently and rapidly.

Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (leaves 148-157).

Thesis--Copenhagen. / Summary in Danish. Includes bibliographical references and index.

Thesis (M.S.)--Rochester Institute of Technology, 2009. / Typescript. Includes bibliographical references (leaves 50-51).

Thesis (Professional Degree)--University of Missouri, School of Mines and Metallurgy, 1926. / The entire thesis text is included in file. Typescript. Title from title screen of thesis/dissertation PDF file (viewed September 15, 2009) Includes bibliographical references and index.

<p> Unconventional oil and gas extraction has been deployed significantly in the United States in recent years. The current study focuses on the impact of hydraulic fracturing (also known as fracking) on the sustainability of water resources in Louisiana. This impact is measured by quantifying the stress for current and future scenarios of fracking water use in the two main shale plays in Louisiana. The assessment is conducted at the HUC-12 fine catchment spatial scale. Initially, sectored stress metrics were calculated for surface and groundwater, respectively, without including fracking water use. Once both stress metrics were estimated with the reported water sources and uses in Louisiana corresponding to the 2010 year, several scenarios for both sources were evaluated. In the <i>first scenario</i>, a peak year (2011) of fracking water use was added as a water demand new category into the stress calculation matrices. The results indicate that a significant variability in the calculated stress metric with and without fracking is reflected only for the groundwater sector. The second <i>Existing wells</i> scenario calculates the stress including the water use of the total number of wells that currently exist in both shale plays over a brief time period. The other additional tested scenario consists of an increase of 100% of the required number of wells to extract the expected total shale play capacity. Results of the <i>additional scenarios</i> follow the same pattern as the <i> first scenario</i>. This analysis can be useful for water management authorities to consider several factors, such as cost analysis of recycled flow-back, as alternative resources for fracking water use. In addition to this fracking water use impact on resources analysis, an educational web-module comprising the Energy-Water Nexus is developed in the current study. The core of the educational module available online is contained in the learning activities development.</p><p>

<p> Dissolved organic matter (DOM) plays an important role in the cycling of nutrients within aquatic ecosystems; however, excess amounts can have detrimental effects on aquatic organisms. Stormwater runoff events in urban areas can contribute high concentrations of DOM to receiving waters, posing potential impairment to the aquatic ecosystems of urban streams and downstream water bodies. Characterizing compositional changes in DOM due to storm events is important for understanding potential downstream water quality effects and has been well studied in forested, agricultural, and urban landscapes. However, <i>in situ</i> sensors have not been widely applied to monitor stormwater contributions in urbanized areas, leaving the spatial and temporal characteristics within these systems poorly understood. Using laboratory measurements of dissolved organic carbon (DOC) concentration and excitation emission matrix spectroscopy (EEMS), fluorescent DOM (FDOM) sensors, and a mobile water quality sensing platform, this study investigated changes in DOM quantity and sources within the Northwest Field Canal (NWFC), an urban water conveyance located in Logan, Utah, USA that receives runoff during storm events. Under baseflow conditions, FDOM decreased and exhibited dampened diurnal variability as the summer irrigation season progressed, while FDOM values at the upstream and downstream monitoring sites were relatively similar. During storm events, FDOM concentrations were rapidly elevated to values orders of magnitude greater than in baseflow measurements, and DOC concentrations were more than 3 times greater at the downstream site than those at the upstream site due to high contributions of DOC being discharged from outfalls. Compositional changes in DOM indicated a shift during storm events from a more autochthonous, less degraded DOM in baseflow to more decomposed and terrestrially derived DOM in stormwater flows. These observations were consistent with results from custom, <i>in situ</i> fluorometers, which also revealed a seasonal transition to a more microbially derived composition in baseflow conditions as the summer season progressed. Deployment of a mobile sensing platform during stormflow conditions confirmed that contributions of DOM were associated with the locations of outfalls discharging runoff into the canal and revealed spatial changes in DOM composition and concentration along canal transects.</p><p>

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