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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
271

ADAPTIVE WATER QUALITY CONTROL IN DRINKING WATER DISTRIBUTION NETWORKS

WANG, ZHONG 30 June 2003 (has links)
No description available.
272

Water Quality in the Cranberry Run Wetland

Houser, Ronald L., Jr. 06 October 2009 (has links)
No description available.
273

Applied Steady-State and Transient Modeling of Mixing Zone Requirements in Streams

Castro, Alvin 01 January 1982 (has links) (PDF)
Two existing stream dispersion computer models were applied to a hypothetical stream to analyze mixing zone requirements due to point and non-point discharges. Mixing zone curves were developed to define acceptable and unacceptable regions of stream response for stead-state and transient conditions. The impact on these regions due to varying quantitative and qualitative characteristics of the stream and waste discharges were investigated. In addition, a sensitivity analysis was conducted on the response of a transient one-dimensional stream dispersion model. A logarithmic linear regression analysis, relating the number of time increments specified to a dimensionless hydrograph shape factor for known storm water and combined events, gave correlation coefficients of 0.915 and0.925 for 94% and 98% model accuracies, respectively.
274

An Investigation of Methods for the Concentration of Chemical Compounds Produced by Actinomycetes and Their Relation to Tastes and Odors in Municipal Water Supplies

Brown, Jerry H. 01 1900 (has links)
It is the purpose of this investigation to improve upon techniques to enhance the taste of municipal water and attempt to devise one that could desorb the compounds from carbon in an unaltered state. It was decided that the odor character would be the criterion used to decide if the eluted compounds were the same as those in the raw water.
275

Validation of a Canadian drinking source water quality index and its application to investigate the spatial scale of land use – source water quality relationships

Hurley, Tim 13 April 2012 (has links)
Source water protection is a key component of the multiple barrier approach to drinking water. The management of contamination within source water ecosystems is associated with many benefits but also several challenges. By its very nature, source water protection is site specific and requires the cooperation of numerous watershed stakeholders to ensure sufficient financial resources and social will. This work focused on two critical aspects of source water protection: 1) The facilitation of effective communication to promote cooperation among watershed stakeholders and aid in public education programs. A drinking source water quality index presents a potential communication and analysis tool to facilitate cooperation between diverse interest groups as well as represent composite source water quality. I tested the effectiveness of the Canadian Council of Ministers of the Environment Water Quality Index (CCME WQI) in capturing expert assessments of surface drinking source water quality. In cooperation with a panel of drinking water quality experts I identified a core set of parameters to reflect common Canadian surface source water concerns. Based upon existing source water guidelines, drinking source water target values were drafted for use in the index corresponding to two basic treatment levels. Index scores calculated using the core parameter set and associated source water target values were strongly correlated with expert assessments of source water quality. Amended with a modified index calculation procedure to accommodate parameters measured at different frequencies within any particular study period, the CCME WQI provides a valuable means of monitoring, communicating, and understanding surface source water quality. 2) The application of source water protection strategies to the appropriate spatial scale in order to manage contaminants of concern in a cost effective manner. Using data gathered from 40 Canadian rivers across 4 western Canadian ecozones I examined the spatial scales at which landuse was most closely associated with drinking source water quality metrics. Linear mixed effects models revealed that different spatial areas of landuse influence drinking source water quality depending on the parameter and season investigated. Microbial risk, characterized using E. coli measures, was only associated with landuse at the local spatial scale. Turbidity measures exhibited a complex association with landuse suggesting that the landuse areas of greatest influence can range from the local to the watershed scale. Total organic carbon concentrations were only associated with landuse characterized at the entire watershed scale. The validated CCME WQI was used to provide a composite measure of seasonal drinking source water quality but did not provide additional information beyond the analyses of individual parameters. These results suggest that entire watershed management is required to safeguard drinking water sources with more focused efforts at targeted spatial scales to reduce identified risk parameters. The source water protection tools and knowledge that I present have immediate application within Canada. Practitioners must be aware of the limitations of the CCME WQI however it provides a validated means of communicating complex source water quality information to non-specialized end users. Combined with the scale dependency of landuse-source water relationships that I elucidated, water quality managers can target contaminant reduction strategies in a more cost-effective manner and relay water quality status and trends to concerned groups. / Graduate
276

A contribution towards real-time forecasting of algal blooms in drinking water reservoirs by means of artificial neural networks and evolutionary algorithms

Welk, Amber Lee. January 2007 (has links)
Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, Discipline of Ecology and Evolutionary Biology, 2008. / "December 2007" Bibliography: pages 172-185. Also available in print form.
277

Assessment of aquatic invertebrate communities of tributaries of the Buffalo River, Arkansas, and evaluation of indices of community integrity /

Mixon-Hinsey, Janice Arlene, January 1900 (has links)
Thesis (M.S.)--Missouri State University, 2008. / "December 2008." Includes bibliographical references (leaves 63-74). Also available online.
278

Transboundary water pollution and its implications for planning and environmental management : Shenzhen-Hong Kong border region as a case study /

Shen, Zi-soen, Belwin. January 1999 (has links)
Thesis (M. Sc.)--University of Hong Kong, 1999. / Includes bibliographical references (leaves 138-145).
279

Design and implementation of a water-quality monitoring program in support of establishing user capacities in Yosemite National Park

Peavler, Rachael S. January 2008 (has links)
Thesis (M.S.)--University of Nevada, Reno, 2008. / "December, 2008." Includes bibliographical references (leaves 79-81). Online version available on the World Wide Web.
280

Role of biological monitoring in water quality assessment and a case study on the Crocodile River, Eastern Transvaal

Roux, Dirk Johannes 14 May 2014 (has links)
M.Sc. (Zoology) / National water quality monitoring in South Africa has in the past mainly focused on measuring physical and chemical variables. However, it is increasingly realised that measuring physical and chemical variables on their own cannot provide an accurate account of the general "health" of an aquatic ecosystem. Biological communities, on the other hand, are accurate indicators of overall environmental conditions. Water quality management must, therefore, rely on comparative data for both chemical composition and biological effects. In fact, it appears as if biological monitoring (biomonitoring) is worldwide becoming a primary tool in assessing environmental condition and verifying compliance with effluent discharge. This study classified different biomonitoring approaches and techniques under bioassessment (referring to the field oriented biomonitoring protocols which make use of biotic indices to assess water quality); bioassays (toxicity tests which is usually laboratory-based); behavioural bioassays (including aspects such as early warning systems, and preference and avoidance studies); bacteriological studies (the monitoring of certain microbes to allow the detection of faecal contamination); measurement of bioaccumulation (referring to the methods by which the uptake and retention of chemicals in the body of an organism can be monitored); and fish pathology (fish health studies dealing with the causes, processes and effects of disease). Habitat assessment and evaluation was identified as an essential part of any biosurvey. There can be little uncertainty about the mutual dependence of habitat quality, biological health and chemical characteristics of water in the environment. Relative habitat condition, as the principal determinant of attainable biological potential, should set the context for interpreting the results of a biosurvey and can be used as a general predictor of biological condition. Chemistry can further help to explain and characterise certain impacts. The Crocodile River, Eastern Transvaal, was selected for conducting a case study. The SASS2 rapid bioassessment protocol, as well as a habitat quality index (Hal) was used during five consecutive biosurveys. From the results obtained in this study, it appears as if biomonitoring can be used to good effect in overall environmental assessment. The SASS2 index appeared to be both a robust and sensitive indicator of environmental condition. Application of the SASS2 technique on a regional or even national basis should be feasible with regard to simplicity and practicality. It is also cheaper and less labour intensive than comprehensive chemical monitoring. However, bioassessments should not replace but rather compliment chemical and physical monitoring.

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