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1
Muyibi, Suleyman Aremu. "Factors affecting coagulation of turbid water and softening hardwater with Moringa oleifera seed extracts." Thesis, University of Newcastle Upon Tyne, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308368.
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Michalíčková, Iveta. "Teplonosné látky otopných soustav." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2017. http://www.nusl.cz/ntk/nusl-265729.
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Theme of diploma thesis is the heat transfer medium in heating systems. The thesis is departed to three parts. In the first part, there is a theoretical solution of heat transfer mediums. In the second part, there is a calculation solution of the project. Project solves heating of the apartment building. There are two variants of heating source and water treatment. Those variants are compared. The last part is experimental part. Theme of the experiment is quality of heating water in heating systems.
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Aguinaldo, Jorge T. "Precipitative Softening and Ultrafiltration Treatment of Beverage Water." Scholar Commons, 2006. http://scholarcommons.usf.edu/etd/3895.
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Lime softening, chlorination, clarification and filtration have been long recognized
treatment processes for beverage water specifically the carbonated soft drink (CSD) because
it provides consistent water quality required for bottling plants, however these processes are
becoming uneconomical and causes more problems than the benefits they offer. These
processes require very large foot print, occupy large plant volume, and generate large
volume of sludge which causes disposal problems. Chlorination produces trihalomethanes
(THMs) and other by-products which are detrimental to health and imparts tastes to the final
products. Using the newly developed submerged spiral wound ultrafiltration membranes in
conjunction with lime softening may replace the conventional lime softening, clarification
and filtration processes.
This research was conducted to demonstrate the feasibility of integrating immersed
ultrafiltration (UF) membrane with lime softening. The objectives of this research was to
achieve the water quality required by the CSD bottlers; determine the relationships of
operating parameters such as pH and membrane flux with trans-membrane pressure (TMP),
and membrane permeability; determine the optimum dosage of lime; evaluate the operating
parameters as basis for the design and construction of the full scale plant; and predict the
membrane cleaning intervals.
A pilot unit consisting of lime reactor and UF system was designed and built for this
research. The pilot unit was operated at various pH ranging from 7.3 to 11.2 and at
membrane flux rates of 15, 30 and 45 gfd. The pilot unit was also operated at the CSD
bottler’s operating conditions which is pH 9.8 at flux of 30 gfd. The pilot unit operated for a
total of 1800 hours. The raw water source was from city water supply.
The filtrate from the pilot unit achieved alkalinity reduction to 20 to 30 mg/L
preferred by CSD bottlers, with lime dosage close to the calculated value. The filtrate
turbidity during the test was consistently within 0.4 to 0.5 NTU. The TMP values obtained
during the test ranges from 0.1 to 2.5 psi, while the permeability values ranges from 18.19 to
29.6 gfd/psi. The increase in flux results to corresponding increase in TMP, and increase in
operating pH, increases the rate of TMP. Permeability decreases with increasing operating
pH. The TOC reduction ranges from 2.6 % to 15.8% with increasing operating pH. No
scaling of the UF membranes was observed during the test. Thirty days UF membrane
cleaning interval was predicted. The results from this research can use as the basis of
designing and operating a full scale Lime Softening UF Treatment Plant.
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Sun, Gwo-Shing 1959. "Water quality of gray water for reuse." Thesis, The University of Arizona, 1986. http://hdl.handle.net/10150/191907.
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This study was designed to evaluate the safety of gray water for reuse purposes. The physical and chemical quality of treated gray water met water reuse standards set by the State of Arizona for surface irrigation purposes. The number of microorganisms in gray water significantly decreased after biological treatment and sand filtration. However, the number of fecal coliform bacteria in treated gray water was still higher than the standard for reuse as set by the State of Arizona for surface irrigation. This is also true for rain water which was stored in a tank. No indigenous Salmonella were isolated from gray water. It was found that both Salmonella typhimurium and Shigella dysenteriae, seeded into gray water, can persist for at least several days. This implied that there may be some risk associated with gray water reuse when the gray water contains these pathogenic bacteria.
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Maier, Stefan Heinrich. "Modelling water quality for water distribution systems." Thesis, Brunel University, 1999. http://bura.brunel.ac.uk/handle/2438/5431.
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Maintaining water quality in distribution systems has become a prominent issue in the study of water networks. This thesis concentrates on disinfectant and particle counts as two important indicators of water quality. The models discussed in this work are based on data collected by the author. The experimental set-up and procedure are described and observations of particle counts, particle counter size distributions, monochloramine as disinfectant, temperature, heterotrophic plate counts and epifluorescence microscopy counts are reported. A model of the response of particle counts to an increase in flow is developed. This model is obtained from specification derived from the data and assumptions, and is validated by its interpretability and its fit to data. A local shear-off density and an initial biofilm shedding profile were introduced and thus a linear model for this part of the water quality dynamics could be obtained. A procedure for the identification of the parameters of the local shear-off function and for the determination of the biofilm shedding profile is presented. This profile can be used to provide information about the status of the distribution system in terms of shear-off from the biofilm on the pipe walls. Monochloramine decay dynamics are investigated. The chlorine meter data is preprocessed with the help of titration data to correct meter drift. The data is then used in calibrating two different possible chlorine models: a model with a single decay coefficient and a model with bulk decay coefficient and wall demand (as used in Epanet). Important difficulties in identifying these parameters that come about because of the structure of the models are highlighted. Identified decay coefficients are compared and tested for flow, inlet chlorine and temperature dependence. The merits and limits of the approach to modelling taken in this work and a possible generalisation are discussed. The water industry perspective and an outlook are provided.
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Kingdon, Lorraine B. "Water Quality Watchdogs." College of Agriculture, University of Arizona (Tucson, AZ), 1988. http://hdl.handle.net/10150/295555.
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House, Margaret A. "Water quality indices." Thesis, Middlesex University, 1986. http://eprints.mdx.ac.uk/13379/.
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Given the present constraints on capital expenditure for water quality improvements, it is essential that best management practices be adopted whenever possible. This research provides an evaluation of existing practices in use within the water industry for surface water quality classification and assesses water quality indices as an alternative method for monitoring trends in water quality. To this end, a new family of indices have been developed and evaluated and the management flexibility provided by their application has been examined. It is shown that water-quality indices allow the reduction of vast amounts of data on a range of determinand concentrations, to a single number in an objective and reproducible manner. This provides an accurate assessment of surface water quality which will be beneficial to the operational management of surface water quality. Previously developed water quality indices and classifications are reviewed and evaluated. Two main types of index are identified: biotic indices and chemical indices. The former are based exclusively upon biological determinands/indicators and are used extensively within the United Kingdom in the monitoring of surface water quality. The latter includes a consideration of both physico-chemical and biological determinands, but with an emphasis on the former variables. Their use is still the subject of much controversy and discussion. Four main approaches to the development of chemical indices can be identified in accordance with the aims and objectives of their design. Those developed for general application are known as General Water Quality Indices (WQIs) or Indices of Pollution, with the latter based predominantly upon determinands associated with man-made pollution. Those which reflect water quality in terms of its suitability for a specific use are termed use-related; whilst planning indices are those which attempt to highlight areas of high priority for remedial action on the basis of more wide-ranging determinands. The derivation and structure of previously developed indices have been evaluated and the merits and strengths of each index assessed. In this way, nine essential index characteristics were identified, including the need to develop an index in relation to legal standards or guidelines. In addition it was recognised that one requirement of an index should be to reflect potential water use and toxic water quality in addition to general quality as reflected by routinely monitored determinands. The development of river quality classifications within the United Kingdom is reviewed and the additional management flexibility afforded by the use of an index evaluated by comparing the results produced by the SOD (1976) Index with those of the National Water Council (NWC, 1977) Classification. The latter classification is that presently used to monitor water quality in Britain. The SOD Index was found to be biased towards waters of high quality and provided no indication of potential water use or toxic water quality. Nevertheless, it displayed a number of advantages over the NWC Classification in terms of the operational management of surface water quality. It was therefore decided to develop a new family of water quality indices, each based upon legally established water quality standards and guidelines for both routinely monitored and toxic determinands and each relating water quality to a range of potential water uses, thereby indicating economic gains or losses resulting from changes in quality. Four stages in the development of a water quality index are discussed: determinand selection; the development of determinand transformations and weightings; and the selection of appropriate aggregation functions. Four separate indices have been developed as a result of this research. These may be used either independently or in combination with one another where a complete assessment of water quality is required. The first of these is a General Water Quality Index (WQI) which reflects water quality in terms of a range of potential water uses. This index is based upon nine physico-chemical and biological determinands which are routinely monitored by the water authorities and river purification boards of England, Wales and Scotland. The second, the Potable Water Supply Index (PWSI) is based upon thirteen routinely monitored determinands, but reflects water quality exclusively in terms of its suitability for use in potable water supply (PWS). The two remaining indices, the Aquatic Toxicity (ATI) and Potable Sapidity (PSI) Indices are based upon toxic determinands such as heavy metals, pesticides and hydrocarbons which are potentially harmful to both human and aquatic life. Both indices are use-related, the former reflecting the suitability of water for the protection of fish and wildlife populations; the latter, the suitability of water for use in PWS. Each index is based upon nine and twelve toxic determinands respectively. These indices were developed in as objective and rigorous a manner as possible, utilising an intensive interview and questionnaire programme with members of both the water authorities and river purification boards. Rating curves were selected as the best way in which individual determinand concentrations could be transformed to the same scale. The scales selected for the WQI and PWSI are 10 - 100 and 0 - 100 respectively, whilst those of the ATI and PSI are 0 - 10. Each has been sub-divided in such a way as to indicate not only water quality, but also possible water use. Thus, the indices reflect both current and projected changes in the economic value of a water body which would occur as a result of the implementation of alternative management strategies. The curves were developed using published water quality standards and guidelines relating to specific water uses. Therefore, they contain information on standards which must be adhered to within the United Kingdom and this adds a further dimension to their management flexibility. Determinand weightings indicating the emphasis placed by water quality experts upon individual determinands were assigned to the determinands of the WQI and PWSI. However, weightings were omitted from the ATI and PSI due to the sporadic nature of pollution events associated with these determinands. These vary spatially and temporally, both in concentration and in terms of which determinand is found to be in violation of consent conditions. Therefore, on a national scale, no one determinand could be isolated as being more important than any other. Three aggregation formulae were evaluated for use within the developed indices: the weighted and unweighted versions of an arithmetic, modified arithmetic and multiplicative formulation. Each index was applied to data collected from a series of water quality monitoring bodies covering a range of water quality conditions. In each instance, the modified arithmetic formulation was found to produce index scores which agreed most closely with a predetermined standard, normally the classifications assigned using the NWC classification. In addition, this formulation produced scores which best covered the ascribed index range. However, the multiplicative unweighted formulation was retained for use within the ATI and PSI for the detection of zero index scores, i.e. when concentrations in excess of legal limits were recorded for these toxic determinands. The results from these studies validate the ability of each index to detect fluctuations in surface water quality. Therefore, the utility of the developed indices for the operational management of surface water quality was effectively demonstrated and the flexibility and advantages of an index approach in providing additional information upon which to base management decisions was highlighted.
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Wang, Zhong. "Adaptive water quality control in drinking water distribution." Cincinnati, Ohio : University of Cincinnati, 2003. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=1052325491.
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Sangameswaran, Sivaramakrishnan. "Water quality modeling of a storm water channel." ScholarWorks@UNO, 2003. http://louisdl.louislibraries.org/u?/NOD,52.
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Thesis (M.S.)--University of New Orleans, 2003.Title from electronic submission form. "A thesis ... in partial fulfillment of the requirements for the degree of Master of Science in Environmental Engineering"--Thesis t.p. Vita. Includes bibliographical references.
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Wang, Yuxin. "Source Water Quality Assessment and Source Water Characterization for Drinking Water Protection." Research Showcase @ CMU, 2014. http://repository.cmu.edu/dissertations/416.
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Source water quality plays a critical role in maintaining the quality and supply of drinking water, yet it can be negatively affected by human activities. In Pennsylvania, coal mining and treatment of conventional oil and gas drilling produced wastewaters have affected source water quality for over 100 years. The recent unconventional natural gas development in the Marcellus Shale formation produces significant volumes of wastewater containing bromide and has the potential to affect source water quality and downstream drinking water quality. Wastewater from coal-fired power plants also contains bromide that may be released into source water. Increasing source water bromide presents a challenge as even small amounts of bromide in source water can lead to carcinogenic disinfection by-products (DBPs) in chlorinated finished drinking water. However, bromide is not regulated in source water and is not removed by conventional drinking water treatment processes. The objective of this work is to evaluate the safe bromide concentration in source water to minimize the cancer risk of trihalomethanes - a group of DBPs - in treated drinking water. By evaluating three years of water sampling data from the Monongahela River in Southwestern Pennsylvania, the present analysis reached three conclusions. First, bromide monitoring for source water quality should be taken at drinking water intake points. Water sample types (river water samples vs drinking water intake samples) can lead to different water quality conclusions and thus affect regulatory compliance decision-making. Second, bromide monitoring at drinking water intake points can serve as a predictor for changes in heavily brominated trihalomethanes concentrations in finished water. Increasing bromide in source water can serve as an early warning sign of increasing formation of heavily brominated trihalomethanes and their associated cancer risks in drinking water. Finally, this work developed a statistical simulation model to evaluate the effect of source water bromide on trihalomethane formation and speciation and to analyze the changing cancer risks in water associated with these changing bromide concentrations in the Monongahela River. The statistical simulation method proposed in this work leads to the conclusion that the bromide concentration in source water must be very low to prevent the adverse health effects associated with brominated trihalomethanes in chlorinated drinking water. This method can be used by water utilities to determine the bromide concentration in their source water that might indicate a need for process changes or by regulatory agencies to evaluate source water bromide issues.
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Abdel-wahab, Ahmed Ibraheem Ali. "The ultra-high lime with aluminum process for removing chloride from recirculating cooling water." Texas A&M University, 2004. http://hdl.handle.net/1969.1/446.
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Chloride is a deleterious ionic species in cooling water systems because it is important in promoting corrosion. Chloride can be removed from cooling water by precipitation as calcium chloroaluminate using ultra-high lime with aluminum process (UHLA). The research program was conducted to study equilibrium characteristics and kinetics of chloride removal by UHLA process, study interactions between chloride and sulfate or silica, and develop a model for multicomponent removal by UHLA.
Kinetics of chloride removal with UHLA was investigated. Chloride removal was found to be fast and therefore, removal kinetics should not be a limitation to applying the UHLA process. Equilibrium characteristics of chloride removal with UHLA were characterized. Good chloride removal was obtained at reasonable ranges of lime and aluminum doses. However, the stoichiometry of chloride removal with UHLA deviated from the theoretical stoichiometry of calcium chloroaluminate precipitation. Equilibrium modeling of experimental data and XRD analysis of precipitated solids indicated that this deviation was due to the formation of other solid phases such as tricalcium hydroxyaluminate and tetracalcium hydroxyaluminate. Effect of pH on chloride removal was characterized. Optimum pH for maximum chloride removal was pH 12 ± 0.2. Results of equilibrium experiments at different temperatures indicated that final chloride concentrations slightly increased when water temperature increased at temperatures below 40oC. However, at temperatures above 40oC, chloride concentration substantially increased with increasing water temperature.
An equilibrium model was developed to describe chemical behavior of chloride removal from recycled cooling water using UHLA. Formation of a solid solution of calcium chloroaluminate, tricalcium hydroxyaluminate, and tetracalcium hydroxyaluminate was found to be the best mechanism to describe the chemical behavior of chloride removal with UHLA.
Results of experiments that studied interactions between chloride and sulfate indicated that sulfate is preferentially removed over chloride. Final chloride concentration increased with increasing initial sulfate concentration. Silica was found to have only a small effect on chloride removal. The equilibrium model was modified in order to include sulfate and silica reactions along with chloride in UHLA process and it was able to accurately predict the chemical behavior of simultaneous removal of chloride, sulfate, and silica with UHLA.
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Bessa, Raquel de Andrade. "Synthesis and characterization of composite magnetic zeolites using kaolin for softening water." Universidade Federal do CearÃ, 2016. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=17007.
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CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel SuperiorThe present work deals about the synthesis and characterization of magnetic zeolites obtained by hydrothermal route using kaolin from Brazilian Northeast as silicon and aluminum source. By means of the X-ray diffraction technique it was possible to identify zeolite LTA and zeolite P1 as major crystalline phases for each synthesis, with low intensity peaks referent to unreacted quartz present in the kaolin used, which is in accordance to the. FTIR spectra; the nanoparticles were identified as magnetite, with low intensity peaks referent to goethite. In scanning electron microscopy, however, it was not possible to morphologically identify these minor components, while the zeolites showed well defined morphologies, presenting unchanged morphology when in the composites form, but with nanoparticles dispersed over their surface, as expected. From transmission electron microscopy it was observed that the nanoparticles were of ca. 50 nm. Magnetic measurements indicated magnetite presence with superior diameter to critical diameter to superparamagnetic particles and remanent magnetization. Thermogravimetric analyses showed for the composites, lower mass loss than compared to the pure zeolites what may be associated to the improvement of its thermal stability. Granulometric distribution indicated nanoparticles agglomeration in variable sizes, while zeolites formed agglomerates of ca. 10 Âm. Water softening was accomplished by using both zeolites, with high efficiency on Ca2+ removal and similar behavior between the zeolite and its respective composite, being the best result observed for zeolite A, with efficiency of 97,95%, reaching equilibrium in the first contact minutes. The dependence on mass studies also showed that zeolite A and its composite presented the best efficiency, whereas zeolite P achieved the same removal levels using corresponding zeolite masses (45 mg). This way, the proposed method for zeolites synthesis proved to be efficient, so that the use of a magnet is capable to attract them, leading their excellent separation from the aqueous medium with its ionic exchange capacity unaffected.
O presente trabalho trata da sÃntese e caracterizaÃÃo de zeÃlitas magnÃticas obtidas por impregnaÃÃo de nanopartÃculas de magnetita a zeÃlitas A e P, sintetizadas por mÃtodo hidrotÃrmico utilizando caulim branco do Nordeste brasileiro como fonte de silÃcio e alumÃnio. Por meio da tÃcnica de difraÃÃo de raios-X foi possÃvel identificar como fases cristalinas majoritÃrias a zeÃlita LTA e P1 para cada sÃntese, com picos de baixa intensidade referentes a quartzo, resistente ao processo tÃrmico de tratamento prÃvio do caulim, bem como nos espectros de infravermelho; as nanopartÃculas foram identificadas como magnetita, havendo ainda indÃcios da presenÃa de goethita em pequena quantidade. Nas anÃlises de microscopia eletrÃnica de varredura, entretanto, nÃo foi possÃvel identificar esses componentes minoritÃrios morfologicamente; enquanto que a morfologia das zeÃlitas mostrou-se bem definida, sem alteraÃÃes apÃs a formaÃÃo dos compÃsitos, apenas com nanopartÃculas espalhadas em sua superfÃcie, como desejado. A partir da microscopia eletrÃnica de transmissÃo, pÃde-se observar melhor a variaÃÃo de tamanho das nanopartÃculas, em mÃdia de 50 nm. Medidas magnÃticas das amostras com essa propriedade indicaram a presenÃa de magnetita com diÃmetro superior ao diÃmetro crÃtico para partÃculas superparamagnÃticas e magnetizaÃÃo remanente. As anÃlises termogravimÃtricas mostraram que a adiÃÃo das nanopartÃculas Ãs zeÃlitas diminuiu sua perda de massa diante do aumento de temperatura e as anÃlises de distribuiÃÃo granulomÃtrica indicaram a aglomeraÃÃo das nanopartÃculas em tamanhos variÃveis, enquanto que as zeÃlitas formaram aglomerados de aproximadamente 10 Âm. Os ensaios de abrandamento de Ãguas mostraram alta eficiÃncia das zeÃlitas em remover Ca2+, com comportamento similar entre a zeÃlita e o seu respectivo compÃsito, encontrando para a zeÃlita A o maior percentual de remoÃÃo, de 97,95 %, atingindo equilÃbrio nos primeiros minutos de aplicaÃÃo. Os estudos de massa tambÃm mostraram a eficiÃncia da zeÃlita A e de seu compÃsito, tendo a zeÃlita P se aproximado dos mesmos nÃveis de remoÃÃo em massas referentes a 45 mg de zeÃlita. Assim, o mÃtodo proposto para sÃntese das zeÃlitas magnÃticas mostrou-se eficiente, de modo que a utilizaÃÃo de um Ãmà à capaz de atraÃ-las facilitando a separaÃÃo do meio apÃs a aplicaÃÃo em meio aquoso e sua capacidade de troca iÃnica nÃo foi afetada.
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Bob, Mustafa M. "Enhanced removal of natural organic matter during lime-soda softening." Connect to this title online, 2003. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1047486107.
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Thesis (Ph. D)--Ohio State University, 2002.Title from first page of PDF file. Document formatted into pages; contains xxii, 119 p.: ill. Includes abstract and vita. Advisor: Harold W. Walker, Civil Engineering Program. Includes bibliographical references (p. 115-119).
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McCormick, Suzanne. "Air and Water Quality." College of Agriculture, University of Arizona (Tucson, AZ), 1992. http://hdl.handle.net/10150/295707.
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Kilungo, Aminata Peter. "Drinking Water Quality Monitoring." Diss., The University of Arizona, 2013. http://hdl.handle.net/10150/306073.
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This dissertation involves two different studies. The first concerns the real-time detection of microbial contamination in drinking water using intrinsic fluorescence of the microorganisms. The prototype, “Blinky”, uses LEDs that emit light at 365nm, 590nm, and 635nm for ultraviolet, amber, and red light, respectively. At 365 nm, the cellular components excited include reduced pyridine nucleotides (RPNs), flavins, and cytochromes to distinguish viable bacteria; at 590 nm, the cellular components excited include cytochromes for non-viable bacteria; at 635 nm, the cellular components excited include calcium dipicolinic acid (DPA) for spores. By using these three different wavelengths, the prototype can differentiate between viable and non-viable organisms and also has the potential to detect spores. The aim of this study was to improve the detection limit by modifying the design of the instrument and to establish the detection limit of viable and non-viable bacteria and spores. The instrument was modified by replacing existing LEDs with LEDs that had 50% more intensity. Two additional LEDs were added for amber and red light, bringing the total to four LEDs for each. The LEDs were also positioned closer to the photomultiplier tube so as to increase sensitivity. For UV, only two LEDs were used as previous. The detection limit of the viable bacteria was ~50 live bacteria/L. No change in the intrinsic fluorescence below the concentration of ~10⁸ dead bacteria/L was observed. The results for spore measurements suggested that most of the spores had germinated before or during the measurements and could not be detected. The instrument was successful in detection of viable bacteria and also differentiating viable and non-viable bacteria. The instrument was not successful in detection of spores. The second study was designed to assess the water quality of well construction in southeastern Tanzania. Three designs were tested: Msabi rope pump (lined borehole and covered), an open well converted into a closed well (uncovered well into a covered and lined well), and an open well (uncovered and may or may not be lined). The study looked at the microbial and chemical water quality, as well as turbidity. The survey included 97 water collection points, 94 wells and three rivers. For microbial analysis, heterotrophic plate count (HPC), total coliforms and E. coli tests were performed. Fifteen of these wells were further analyzed for microflora and diversity for wells comparison purposes, using culture methods, followed by polymerase chain reaction (PCR) and genome sequencing. Ten wells out of the fifteen were analyzed for calcium (water hardiness), potassium, nitrates, nitrites, chloride, fluoride, bromide, sulfate, iron, and arsenic. Two water collection points were also selected for organic compound analysis (gasoline components). All samples tested positive for coliforms. Two samples tested positive for Escherichia coli for the lined borehole (Msabi rope pump) and four samples from closed wells. All open wells tested positive for E. coli. There was more microbial diversity in open wells than the closed wells and Msabi rope pumps. Potential bacterial pathogens were detected in seven wells out of the fifteen examined. The wells that tested positive were one Msabi rope pump, one closed well; the rest were from open water sources. Open wells had high turbidity followed by closed wells. Msabi rope pumps had low turbidity comparing to the two wells designs. No traces of gasoline components were detected in any of the water sources. One well out of ten had high amounts of nitrates-nitrogen (> 10 mg/L). The results of this study showed that the Msabi rope pumps performed comparably to the closed wells in terms of microbial quality but performed better with regard to turbidity. The open wells performed poorly in terms of microbial water quality as well and turbidity. There was a statistical difference in HPC, total coliforms, E.coli numbers and turbidity between open wells, closed wells and the Msabi rope pumps. However, there was no statistical difference in HPC, total coliforms and E.coli numbers between the closed wells and Msabi rope pumps. Msabi rope pumps performed better in turbidity
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Courtis, Benjamin John. "Water quality chlorine management." Thesis, University of Birmingham, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289743.
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Erickson, Victoria Gillispie. "Designing for Water Quality." Thesis, Virginia Tech, 2000. http://hdl.handle.net/10919/35105.
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The following document serves as a design guidebook to assist landscape architects, designers, planners, engineers, and architects in the practice of developing land while preserving water quality. This guidebook outlines methods for maximizing permeable surfaces by providing examples of ways to minimize impervious surfaces.Master of Landscape Architecture
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O'Donnell, Alissa J. "Strontium in Drinking Water: Occurrence, Distribution, and Removal." University of Cincinnati / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1416230946.
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Tukker, Mary Jean. "Water quality information system for integrated water resource management." Thesis, Stellenbosch : Stellenbosch University, 2000. http://hdl.handle.net/10019.1/52054.
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Thesis (MEng)--University of Stellenbosch, 2000.ENGLISH ABSTRACT: The processes of monitoring, modelling and managing the water quality of a catchmerit system including all its unique complexities and interrelationships requires an innovative tool or set of tools to help water managers with their decision making. Numerous methods and tools have been developed to analyse and model the real world. However, many of these tools require a fair degree of technical expertise and training to operate correctly and their output may have to be translated or converted to meaningful information for decision-making using a further set of analytical and graphical display tools. A more appropriate technique for management would be to combine all these functions into a single system. The objective of this research was to develop one such tool, an integrated water quality information system (WQIS). A review of the literature revealed that there has been extensive research and development of tools for the management of individual aspects of water resource distribution, augmentation and quality. However, these tools have rarely been integrated into a comprehensive information system offering decision support to a wide variety of river users and managers. Many of the literature sources also noted that a process of interactive development and integration (i.e. including the intended users in the decision of which components to include, the interface design and the graphical display and output) was vital to ensuring the information system becomes an integral part of the users routine work and decision-making. The WQIS was developed using the recommendations from numerous knowledgeable persons in response to questionnaires, interviews and a prototype demonstration. It includes the results of hydrodynamic river and reservoir simulations and the ability to perform operational river scenario testing. However, the development process is continual and always evolving based on the current or local requirements of water managers. These further developments and research needs are discussed in more detail in the conclusion.
AFRIKAANSE OPSOMMING: Die proses om die waterkwaliteit van 'n opvanggebied, met al die unieke kompleksiteite en onderlinge verhoudings van so 'n stelsel te monitor, modelleer en bestuur, vereis 'n innoverende instrument om waterbestuurders te ondersteun in hul besluitnemings. Talle instrumente en metodes vir die ontleding en modellering van die werklikheid is reeds ontwikkel. Die gebruik van hierdie instrumente vereis gewoonlik 'n redelike mate van tegniese kundigheid en opleiding. Dit mag verder nodig wees om die uitvoer van sulke instrumente te vertaal en/of om te skakel na betekenisvolle inligting vir besluitneming deur die gebruik van bykomende analitiese en grafiese vertoon instrumente. 'n Meer toepaslike bestuurstegniek sou wees om al die funksies in 'n enkele stelsel te kombineer. Die doel van hierdie navorsing was om een so 'n instrument, naamlik 'n geïntegreerde waterkwaliteit inligtingstelsel (WQIS), te ontwikkel. 'n Hersiening van bestaande literatuur het getoon dat daar omvattende navorsing en ontwikkeling van instrumente gedoen is vir die bestuur van individuele aspekte van waterbronverspreiding, waterbronaanvulling en waterkwaliteit. Integrasie van hierdie instrumente, in 'n uitgebreide stelsel wat besluitnemingsondersteuning aan 'n verskeidenheid riviergebruikers en bestuurders bied, kom egter selde voor. Verskeie literatuurbronne het ook aangedui dat 'n proses van interaktiewe ontwikkeling en integrasie (m.a.w. in agname van die voorgenome gebruikers se behoeftes in die kense van komponente, die gebruiker raakvlak ontwerp en grafiese vertoon instrumente en uitvoer) noodsaaklik is om te verseker dat die inigtingstelsel 'n integrale deel word van die gebruiker se daaglikse roetine en besluitnemingsproses. Die WQIS is ontwikkel deur gebruikmaking van die insette en aanbevelings van verskeie kenners in reaksie op vraelyste, onderhoude en 'n demonstrasie van 'n prototype. Dit sluit in die resultate van hidro-dinamiese rivier en dam simulasies en die vermoë om operasionele rivier scenario ontledings uit te voer. Die ontwikkeling is egter 'n deurlopende proses, gebaseer op huidige of plaaslike behoeftes van waterbestuurders. Hierdie verdere ontwikkelings- en navorsingsbehoeftes word meer breedvoerig in die gevolgtrekkings bespreek.
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Evans, R. "Water quality requirement for oil industry water injection projects." Thesis, Cranfield University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333540.
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WANG, ZHONG. "ADAPTIVE WATER QUALITY CONTROL IN DRINKING WATER DISTRIBUTION NETWORKS." University of Cincinnati / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1052325491.
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Shang, Feng. "INPUT-OUTPUT WATER QUALITY MODEL IN WATER DISTRIBUTION SYSTEM." University of Cincinnati / OhioLINK, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1028649564.
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JIA, Xuexiu. "EXTENDED METHODOLOGY FOR WATER RESOURCES AND WATER-RELATED ENERGY ASSESSMENT ADDRESSING WATER QUALITY." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2020. http://www.nusl.cz/ntk/nusl-433451.
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Problémy s vodou, zejména její nedostatek a znečištění, ovlivňují každodenní lidský život a hospodářský vývoj. Globální změny klimatu zvyšují pravděpodobnost a četnost extrémních událostí jako jsou sucho a záplavy. Rostoucí problémy s nepravidelnou dostupností a znečištěním vody vyžadují pokročilejší metodiky hodnocení vodních zdrojů, které povedou k efektivnímu využití a hospodaření s vodou. Tato práce se zabývá rozšířenými metodikami pro hodnocení vody z pohledu její kvality a kvantity a pro hodnocení spotřeby energie a produkce emisí souvisejících s vodou. Tři hlavní metodiky jsou navrženy na základě konceptu vodní stopy (Water Footprint) a pinch analýzy vody (Water Pinch Analysis) pro posouzení kvantitativních a kvalitativních hledisek využití a spotřeby vody. Použití těchto metod je rovněž demonstrováno pomocí numerických a empirických případových studií zaměřených na hodnocení a optimalizaci využití regionálních a průmyslových vodních zdrojůDále jsou diskutovány souvislosti mezi vodou a energií (Water-Energy Nexus) za účelem analýzy problémů týkající se vody z širší perspektivy. Z pohledu vody a vodních zdrojů je provedeno počáteční zhodnocení energetické náročnosti a produkce emisí skleníkových plynů v problematice odsolování mořské vody. Výsledky prezentované v této práci navazují na současné metodiky hodnocení vodních zdrojů. Stopa dostupnosti vody (Water Availability Footprint) byla navržena pro zohlednění dopadu degradace kvality vody ve stávajících postupech pro posuzování nedostatku vody, ve kterých nebyla dříve řešena. Druhým přínosem této práce je návrh konceptu kvantitativní-kvalitativní vodní stopy (Quantitative-Qualitative Water Footprint - QQWFP), ve kterém je definována vodní stopa z pohledu nákladů a následně je stanovena v souvislosti s celkovými náklady na spotřebu vody a odstraňování kontaminantů, které se do vody dostávají v průběhu jejího využití. Vodní stopa založená na nákladech poskytuje výsledky, které jsou intuitivnější jak pro management vodních zdrojů tak i pro veřejnost. Tento přístup umožňuje lépe kontrolovat a řídit průmyslové a regionální využívání a správu vody. Třetím přínosem této práce je rozšíření pinch analýzy nedostatku vody (Water Scarcity Pinch Analysis - WSPA), ve které je aplikována pinch analýzy vody na makroúrovni se zaměřením na regionální hodnocení a optimalizaci zdrojů a využívání vody. Všechny tři navržené metody jsou zaměřeny na stanovení dopadů využití vody z hlediska jejího množství a kvality, analýzy QQWFP a WSPA také pokrývají dopady vícečetných kontaminantů. Kromě hledání řešení se tato práce také pokouší naznačit potenciální směry pro budoucí výzkum v dané oblasti. Mezi významná potenciální témata k diskuzi patří 1) pokročilejší metoda kvantifikace vlivu více kontaminantů a 2) implementace a analýza ekonomické proveditelnosti přístupů WSPA a QQWFP s lokalizovanými daty s cílem nalézt přizpůsobené řešení pro optimální využití regionální a průmyslové vody.
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Boyd, Nathan Andrew. "Impact of sediment-water interactions upon overlying water quality in an urban water system." Thesis, Manchester Metropolitan University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366236.
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Schal, Stacey L. "WATER QUALITY SENSOR PLACEMENT GUIDANCE FOR SMALL WATER DISTRIBUTION SYSTEMS." UKnowledge, 2013. http://uknowledge.uky.edu/ce_etds/13.
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Water distribution systems are vulnerable to intentional, along with accidental, contamination of the water supply. Contamination warning systems (CWS) are strategies to lessen the effects of contamination by delivering early indication of an event. Online quality monitoring, a network of sensors that can assess water quality and alert an operator of contamination, is a critical component of CWS, but utilities are faced with the decision of what locations are optimal for deployment of sensors. A sensor placement algorithm was developed and implemented in a commercial network distribution model (i.e. KYPIPE) to aid small utilities in sensor placement. The developed sensor placement tool was then validated using 12 small distribution system models and multiple contamination scenarios for the placement of one and two sensors.
This thesis also addresses the issue that many sensor placement algorithms require calibrated hydraulic/water quality models, but small utilities do not always possess the financial resources or expertise to build calibrated models. Because of such limitations, a simple procedure is proposed to recommend optimal placement of a sensor without the need for a model or complicated algorithm. The procedure uses simple information about the geometry of the system and does not require explicit information about flow dynamics.
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Webb, David W. "WATER QUALITY VARIATIONS DURING NITRIFICATION IN DRINKING WATER DISTRIBUTION SYSTEMS." Master's thesis, University of Central Florida, 2004. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4492.
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This thesis documents the relationship among the major water quality parametersduring a nitrification episode. Nitrification unexpectedly occurred in a chloraminated pilotdrinking water distribution system practicing with a 4.0 mg/L as Cl[subscript 2] residual dosed at 4.5:1Cl[subscript 2]:NH[subscript 3]-N. Surface, ground and sea water were treated and disinfected withmonochloramines to produce finished water quality similar to regional utility water quality.PVC, galvanized, unlined cast iron and lined iron pipes were harvested from regionaldistribution systems and used to build eighteen pilot distribution systems (PDSs). The PDSswere operated at a 5-day hydraulic residence time (HRT) and ambient temperatures.As seasonal temperatures increased the rate of monochloramine dissipation increaseduntil effluent PDS residuals were zero. PDSs effluent water quality parameters chloraminesresidual, dissolved oxygen, heterotrophic plate counts (HPCs), pH, alkalinity, and nitrogenspecies were monitored and found to vary as expected by stoichiometry associated withtheoretical biological reactions excepting alkalinity. Nitrification was confirmed in thePDSs. The occurrence in the PDSs was not isolated to any particular source water.Ammonia for nitrification came from degraded chloramines, which was common among allfinished waters. Consistent with nitrification trends of dissolved oxygen consumption,ammonia consumption, nitrite and nitrate production were clearly observed in the PDSs bulkwater quality profiles. Trends of pH and alkalinity were less apparent. To controlnitrification: residual was increased to 4.5 mg/L as Cl[subscript 2] at 5:1 Cl[subscript 2]:NH[subscript 3]-N dosing ratio, and theHRT was reduced from 5 to 2 days. Elimination of the nitrification episode was achieved after a 1 week free chlorine burn.M.S.
Department of Civil and Environmental Engineering
Engineering and Computer Science
Civil and Environmental Engineering
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Achimore, Ian Garner. "Public funding and water coalitions do they improve water quality? /." Connect to Electronic Thesis (CONTENTdm), 2009. http://worldcat.org/oclc/449187539/viewonline.
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Alere, Ilze. "Aspects of water quality dynamics in drinking water distribution systems." Licentiate thesis, Luleå tekniska universitet, 1997. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-16878.
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Shi, Yi. "Biofilm impacts on water quality in drinking water distribution systems." Thesis, Cardiff University, 2018. http://orca.cf.ac.uk/111782/.
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Drinking water distribution systems (DWDSs) account for the majority of the infrastructure for transporting water from treatment plants to customers’ tap. During the transportation, water quality deteriorates due to the unavoidable accumulation of biofilm within the pipelines. The microbial activity and ecology within the biofilm have great impact on the water quality degradation process. Within DWDSs using chloramine as disinfectant, nitrification caused by nitrifying bacteria is increasingly becoming a concern as it poses a great challenge for maintaining water quality. In order to control nitrification in DWDSs, it is essential to consider both the nitrifying bacteria and their shelter. Hence, the overall aim of this study is to investigate nitrification properties under different operational conditions, in addition to biofilm characteristics in chloraminated water distribution systems. To achieve the aim, nitrifying biofilm was firstly incubated within a flow cell experimental facility. A total of four test phases were conducted to investigate the effects on the extent of nitrification of five flow rates (2, 4, 6, 8 and10 L/min) and four disinfection strategies (total chlorine=1mg/L, Cl2/NH3=3:1; total chlorine=1mg/L, Cl2/NH3=5:1; total chlorine=5mg/L, Cl2/NH3=3:1; and total chlorine=5mg/L, Cl2/NH3=5:1). Physico-chemical parameters and nitrification indicators were monitored during the tests. The main results from the study indicate that nitrification is affected by hydraulic conditions and the process tends to be severe when the fluid flow transforms from laminar to turbulent (2300 < Reynold number < 4000). Increasing disinfectant concentration and optimizing Cl2/NH3 mass ratio were found to have limited efficacy for controlling nitrification. Furthermore, several nitrification indicators were evaluated for their prediction efficiency and the results suggest that the change of nitrite, together with total organic carbon (TOC) and turbidity can indicate nitrification potential more efficiently. At the end of the tests, genomic DNA from biofilm and bulk water from each flow cell unit running at different operational conditions were subjected to a next generation sequencing (NGS) analysis by Illumina MiSeq. The results obtained showed that the microbial community and structure was different between biofilm and water samples. There was no statistical difference in microbial community in biofilm identified between different hydraulic regimes, suggesting that biofilm is a stable matrix to environment. Results further showed that Cl2/NH3 mass ratio had obvious effect on microbial structure in biofilm. This suggests that excessive ammonia is an influencing factor for microbial activity within biofilm. Within bulk water, species richness and diversity tended to be higher at lower hydraulic regimes. This confirms the influence of hydraulic condition on biofilm mechanical structure and further material mobilization to water. Opportunic pathogens such as Legionella and Mycobacterium were detected in abundance in the experimental system. This confirms that nitrification can lead to a decrease of water quality and microbial outbreaks. The characteristics of extracellular polymeric substance (EPS) from biofilm conditioned under different operational conditions were also analysed. Carbohydrate was found to be the main components within biofilm’s EPS. EPS composition and structure were found to be governed by operational conditions, but no simple linear relationship was found. This suggests the interactive effects of EPS properties, hydraulics and disinfectant strategies. EPS effects on disinfection were evaluated via disinfectant decay tests. EPS was confirmed to have an influencing in biofilm overcoming disinfection.
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Telci, Ilker Tonguc. "Optimal water quality management in surface water systems and energy recovery in water distribution networks." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/45861.
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Two of the most important environmental challenges in the 21st century are to protect the quality of fresh water resources and to utilize renewable energy sources to lower greenhouse gas emissions. This study contributes to the solution of the first challenge by providing methodologies for optimal design of real-time water quality monitoring systems and interpretation of data supplied by the monitoring system to identify potential pollution sources in river networks. In this study, the optimal river water quality monitoring network design aspect of the overall monitoring program is addressed by a novel methodology for the analysis of this problem. In this analysis, the locations of sampling sites are determined such that the contaminant detection time is minimized for the river network while achieving maximum reliability for the monitoring system performance. The data collected from these monitoring stations can be used to identify contamination source locations. This study suggests a methodology that utilizes a classification routine which associates the observations on a contaminant spill with one or more of the candidate spill locations in the river network. This approach consists of a training step followed by a sequential elimination of the candidate spill locations which lead to the identification of potential spill locations. In order to contribute the solution of the second environmental challenge, this study suggests utilizing available excess energy in water distribution systems by providing a methodology for optimal design of energy recovery systems. The energy recovery in water distribution systems is possible by using micro hydroelectric turbines to harvest available excess energy inevitably produced to satisfy consumer demands and to maintain adequate pressures. In this study, an optimization approach for the design of energy recovery systems in water distribution networks is proposed. This methodology is based on finding the best locations for micro hydroelectric plants in the network to recover the excess energy. Due to the unsteady nature of flow in water distribution networks, the proposed methodology also determines optimum operation schedules for the micro turbines.
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Clinch, John Richard. "Remote spectrophotometric water quality monitoring." Thesis, University of Hull, 1988. http://hydra.hull.ac.uk/resources/hull:5897.
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The conventional approach to water quality monitoring is to combine periodic sampling with batch analysis in the laboratory. Such a procedure is both labour intensive and time consuming, there are likely to be sample stability and contamination problems, and the information provided is unlikely to be continuous or immediate. This research focussed on the design and construction of fully automated and portable monitors based on flow injection analysis and incorporating solid state photometric detectors. A novel solid state photometric detector was constructed, incorporating light emitting diodes as the light source, which could be used in conjunction with flow injection analysis. Manifolds were studied for a range of species of interest (phosphate, nitrate, ammonia and aluminium) in the field of water quality monitoring and were optimised for their suitability for continuous use. An automated monitor for nitrate was constructed and long term evaluation trials were carried out at several locations for water quality monitoring. Results are also presented for the use of a nitrate monitor in hydroponic cultivation. An automated monitor was also built for the monitoring of ammonia levels in natural waters, which was field tested on the River Avon (Wiltshire). A manifold was also evaluated for the monitoring of residual aluminium levels in drinking water and is currently being commissioned at a water treatment works in Somerset.
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Wright, Julian Paul. "Water quality in estuarine impoundments." Thesis, Durham University, 2002. http://etheses.dur.ac.uk/4027/.
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The impounding of estuaries is currently a popular approach to urban regeneration in the UK, with barrages constructed (Tees, Wansbeck, Tawe, Cardiff Bay, Lagan and Clyde) or proposed (Usk, Loughor, Neath, Hayle, Avonmouth and Ipswich) nationwide. Impounding fundamentally alters the dynamics of estuaries with consequences in terms of sedimentation patterns and rates, ecology, flooding, groundwater, etc. This thesis presents the findings from research into the effects of impounding on estuarine water quality. A series of surveys of a range of physical and chemical parameters were carried out within four estuaries representing the complete range of tidal modification by barrage construction. Internal versus external controls on water quality are distinguished. General water quality in estuarine impoundments is good, but significant problems occur where water bodies show entrenched density stratification, with anoxia and associated increases in ammonia and metal concentrations developing. Stratification related problems are worse in partial than total tidal exclusion impoundments (although a higher rate of tidal overtopping shortens the isolation periods of deep anoxic waters), and low water quality at depth is observed over the majority of the year. The potential for eutrophication is increased by barrage construction, although phosphorus (generally the limiting nutrient) is shown to be catchment sourced, with internal cycling from sediment insignificant. Sediment thickness is shown not to be a control on water quality, although sediment build-up over time eventually leads to a loss of amenity value. Sterol fingerprints are used to identify sewage inputs to the impoundments. Advice for barrage planners and designers is given, including the exclusion and removal of saline water, provision of destratification/aeration devices, control of nutrient inputs, and modelling of sediment loads and deposition. This study has shown that catchment management is fundamental in the sustainability of estuarine impoundments.
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Nagavalli, Venkata Raja Satya Teja. "Smart Discrete Water Quality Sensor." University of Akron / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=akron1449272008.
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Keen, Michael. "Evaluation of the impact of membrane change at a membrane softening water treatment plant." [Tampa, Fla] : University of South Florida, 2009. http://purl.fcla.edu/usf/dc/et/SFE0002961.
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Gemesi, Zsolt. "Plumbing agricultural landscapes for water quality improvement coexistence of intensive agriculture and good water quality /." [Ames, Iowa : Iowa State University], 2007.
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Silva, Carlos G. "Calculating Willingness-To-Pay As a Function of Biophysical Water Quality and Water Quality Perceptions." DigitalCommons@USU, 2014. https://digitalcommons.usu.edu/etd/3325.
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When estimating economic value associated with changes in water quality, recreation demand models typically depend upon either (i) biophysical measures of water quality as collected by natural scientists or (ii) the perception of water quality by recreationists. Models based upon biophysical metrics (such as oxygen concentration, pollutant concentrations, Secchi depth measurements, etc.) operate on the assumption that people can perceive and respond to these metrics, or respond to factors that are, indeed, correlated with the biophysical measure. Economists have often estimated willingness-to-pay (WTP) measures associated with unit changes in biophysical measures without examining the degree to which the measures are truly correlated with perceptions. Recreation demand models that are based upon respondents’ perceptions of water quality necessarily assume that perceptions correlate well with the measures used by scientists to evaluate water quality. Again, WTP for unit changes in perceptions have been estimated without examining the relationship to the underlying biophysical measures. The relationship between biophysical metrics and perceptions is rarely addressed, yet it has profound implications for water quality management and policy. Consider a federal or state agency wishing to manage the quality of its waters in an economically efficient way. Through mandated water quality monitoring regulations, an agency may have many years of biophysical measurements, but these measures are in no way linked to people’s perceptions of water quality and, thus, to WTP.
Using biophysical measures of water quality and recreation use data recently collected in Utah, this study links technical measures of water quality at a water body to survey respondents’ perceptions of water quality at the same site. This approach is akin to estimating an ecological production function wherein biophysical measures are “inputs” to water quality perceptions (the output). Truncated Negative Binomial models of water-based recreation are used to estimate welfare effects of changes in water quality as measured through (i) unit changes in biophysical measures, (ii) unit changes in perceptions, and (iii) unit changes in biophysical as they change perceptions through the ecological production function.
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Stinson, Christian David. "Changes in Water Quality During Recharge of Central Arizona Project Water." Thesis, The University of Arizona, 1999. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_etd_hy0011_m_sip1_w.pdf&type=application/pdf.
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Coltman, Kenna Marie. "Water table management effects on water quality : a soil column study /." Connect to resource, 1992. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1195165287.
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Hansen, Allison Jean. "Water quality analysis of the piped water supply in Tamale, Ghana." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/90019.
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Thesis: M. Eng., Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2014.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 55-56).
The United Nation's Millennium Development Goal Target 7.C is to "halve, by 2015, the proportion of the population without sustainable access to safe drinking water". While the UN claimed to have met this goal, studies have shown that the "improved" sources used as a metric to track progress do not always supply safe water. One example of these improved sources is the piped water in Tamale, Ghana, which is an intermittent system. The question raised and goal of this research is to determine whether this water source is indeed safe. The Ghana Water Company Ltd. in Tamale had handwritten notebooks containing almost ten years of water quality sample data. This data was entered into a computer database so it could be analyzed for seasonal and geographic trends as well as to gain an understanding of overall water quality. From this analysis, it was concluded that seasonal trends do impact the pH and turbidity of source water which influences the water provided to consumers. In addition, 42% of samples did not comply with accepted World Health Organization guidelines for residual free chlorine concentrations. Total coliform was present in 2% of samples. Observations of environmental factors made during field work in Tamale found five "no" answers to a sanitary survey indicating at least a medium contamination risk. Overall, these observations indicate that water from the piped network in Tamale is not always safe. Contamination also happens very readily during storage due to high usage of unsafe storage containers in Tamale combined with the low chlorine residuals.
by Allison Jean Hansen.
M. Eng.
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Wu, Sophia(Sophia W. ). "Understanding the effect of intermittent water supply on drinking water quality." Thesis, Massachusetts Institute of Technology, 2021. https://hdl.handle.net/1721.1/131001.
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Thesis: S.M. in Technology and Policy, Massachusetts Institute of Technology, School of Engineering, Institute for Data, Systems, and Society, Technology and Policy Program, February, 2021Cataloged from the official PDF of thesis.
Includes bibliographical references (pages 78-82).
There are nearly 1 billion people who obtain their drinking water through piped distribution networks that operate intermittently. Intermittent Water Supply (IWS) operations allow for periods of stagnation and depressurization that create conditions favorable for biofilm growth on pipe surface. Biofilms are complex microbial communities that are likely sources of opportunistic waterborne pathogens and can cause disease outbreaks. Flushing of the water pipes and re-pressurization, which occur at the start of each IWS supply cycle, cause the erosion of the biofilm and its transport into the bulk water, which can potentially contaminate the drinking water. This thesis describes the development and proof-testing of an experimental pipe testbed installed on the Nanyang Technological University (NTU) campus in Singapore.
The testbed comprises an array of 100 mm diameter PVC pipes, supplied from a water tank with flow paths controlled through a set of valves, and water samples obtained at up to 7 pipe outlets. Data are presented from an initial program of tests that compare the effects of priming for two pipe sections: 1) with continuous laminar flow (Continuous Water Supply, CWS) under pressure; and 2) IWS, where the pipe section is flushed during re-pressurization (supply period) and then allowed to drain and stagnate for the remainder of the daily cycle. The change of the water quality from both the inlet and outlet was evaluated by determining the microbial load using flow cytometry (with Live/Dead staining), together with physical and chemical water parameters measured on a time series of water samples.
The data compare the response of the CWS pipe section for steady laminar flow, with the transient response following a step-change in flow rate (turbulent conditions) with transient behavior during flushing of the IWS section. Initial filling of the IWS section cause a significant increase in total and live cell counts, confirming that erosion of biofilm can contribute to biomass transported in the bulk water. Further tests are in progress to validate and replicate these results.
by Sophia Wu.
S.M. in Technology and Policy
S.M.inTechnologyandPolicy Massachusetts Institute of Technology, School of Engineering, Institute for Data, Systems, and Society, Technology and Policy Program
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Xie, Xiongfei. "Operation Optimization and Water Quality Simulation of Potable Water Distribution System." Scholar Commons, 2014. https://scholarcommons.usf.edu/etd/5406.
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A potable water distribution system (WDS) consists of pipes, pumps, valves, storage tanks, control and supporting components. Traditionally, it has two basic functions. First, provides end users with potable water at sufficient pressures and good water quality. Second, provides sufficient pressure and flow for fire fighting. Currently, potable water is still the least expensive material for fire fighting. To accomplish these two goals, water utilities have to consider the integrity and security of the water network. As a result, this research selected three research topics that are closely related to the daily operation of water utilities and water quality simulation.
The first study is on optimal sampling design for chlorine decay model calibration. Three questions are investigated: (1) What is the minimum number of chlorine sample locations a water network needs? (2) How many combinations of sampling locations are available? (3) What is the optimal location combination? To answer the first two questions, the mathematical expressions of the chlorine concentrations between any two sampling locations are developed and sampling point relationship matrices are generated, then a mixed integer programming (MIP) algorithm is developed. Once obtained, the solutions to the first two questions are used to calculate the chlorine decay wall reaction coefficients and sensitivity matrix of chlorine concentration wall reaction coefficients; then, sampling location combinations achieved in the second question are sorted using a D-optimality algorithm. The model frame is demonstrated in a case study. The advantage of this method, compared to the traditional iterative sensitivity matrix method, is that a prior knowledge or estimation of wall reaction coefficients is not necessary.
The second study is on optimizing the operation scheduling of automatic flushing device (AFD) in water distribution system. Discharging stagnant water from the pipeline through AFD is a feasible method to maintain water quality. This study presents a simulation-based optimization method to minimize total AFD discharge volume during a 24-hour horizon. EPANET 2.0 is used as hydraulics and water quality simulator. This is formulated as a single objective optimization problem. The decision variables are the AFD operation patterns. The methodology has three phases. In the first phase, AFD discharge capacities are calculated, whether existing AFDs are able to maintain chlorine residuals in the water network is also evaluated. In the second phase, the decision variables are converted to AFD discharge rates. A reduced gradient algorithm is used to quickly explore and narrow down the solution space. At the end of this phase, decision variables are switched back to the AFD operation patterns. In the third phase, simulated annealing is used to search intensively to exploit the global minimum. The method is demonstrated on the water system located at the south end of Pinellas County, Florida where AFD optimal operation patterns are achieved.
The third study is on simulating contaminant intrusion in water distribution system. When contaminant matrix is introduced into water distribution system, it reacts with chlorine in bulk water rapidly and causes fast disinfectant depletion. Due to the difficulties in identifying contaminant types and chemical and biological properties, it is a challenging task to use EPANET-MSX to simulate chlorine decay under contaminant attack. EPANET 2.0 is used in the study to accomplish this goal. However, EPANET 2.0 cannot directly simulate chlorine depletion in the event of contamination attack because it assigns one time-independent bulk reaction coefficient to one specific pipe during the simulation. While under contaminant intrusion, chlorine decay bulk coefficient is not a constant. Instead, it is a temporal and spatial variable. This study presents an innovative approach for simulating contaminant intrusion in water distribution systems using EPANET multiple times. The methodology has six general steps. First, test bulk reaction coefficients of contaminant matrix in chemical lab. The uniqueness of this study is that the contaminant matrix is studied as a whole. The investigations of chemical, biological properties of individual aqueous constituents are not needed. Second, assume the contaminants as nonreactive, using EPANET 2.0 to identify where, when and at what concentrations of the inert contaminants will pass by in the water network. Third, determine the number of chlorine residual simulations based on the results in step two. Fourth, use EPANET to simulate the chlorine residual in the water network without the occurrence of contamination. Fifth, assign contaminated bulk coefficients to contaminated pipes; use EPANET to simulate the chlorine residual in the pipe network. Lastly, the chlorine concentrations of the impacted moments of impacted junctions are replaced with the results calculated in step five. This methodology is demonstrated in the south Pinellas County water distribution system.
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McNeill, Laurie S. "Water Quality Factors Influencing Iron and Lead Corrosion in Drinking Water." Diss., Virginia Tech, 2000. http://hdl.handle.net/10919/28242.
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Corrosion is one of the most complicated and costly problems facing drinking water utilities. Corrosion of iron pipes can lead to economic losses and customer complaints, while lead corrosion poses a serious health risk.
This work first synthesizes nearly 100 years of iron corrosion research to provide the water industry with an updated understanding of factors that influence iron pipe corrosion including water quality and composition, flow conditions, biological activity, and corrosion inhibitors. Potential impacts of upcoming regulations on iron corrosion are also considered. Next, a four-year study is presented that evaluated the effect of water quality and phosphate inhibitors on the corrosion of iron pipes under extended stagnant water conditions. Surprisingly, many of the water quality parameters traditionally thought to influence iron corrosion were not controlling under these "worst case" stagnant conditions. Moreover, addition of phosphate inhibitors often had either no statistically significant effect or actually increased iron concentration, scale build-up and overall weight loss.
Temperature is often overlooked when corrosion of distribution systems pipes is considered. Temperature impacts many parameters that are critical to pipe corrosion including physical properties of the solution, thermodynamic and physical properties of corrosion scale, chemical rates, and biological activity. Moreover, variations in temperature and temperature gradients may give rise to new corrosion phenomena worthy of consideration by water treatment personnel. In laboratory experiments, cast iron samples at 5° C had 23% more weight loss, ten times higher iron release to water, and twice as much tuberculation compared to samples at 25°C.
For lead corrosion, hexametaphosphate inhibitors were proven to increase release of both particulate and soluble lead to drinking water by 200 - 3500% over a wide range of water qualities when compared to orthophosphate, effectively ending a long term debate as to their impacts. Utilities should consider these adverse effects whenever polyphosphate is used to prevent scaling or iron precipitation.Ph. D.
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Coltman, Kenna Maria. "Water table management effects on water quality: a soil column study." The Ohio State University, 1992. http://rave.ohiolink.edu/etdc/view?acc_num=osu1195165287.
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LI, ZHIWEI. "NETWORK WATER QUALITY MODELING WITH STOCHASTIC WATER DEMANDS AND MASS DISPERSION." University of Cincinnati / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1147989825.
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Tilley, Aleceia Marie. "Comparison study of the states of Washington and Oregon's total maximum daily load (TMDL) process." Online pdf file accessible through the World Wide Web, 2007. http://archives.evergreen.edu/masterstheses/Accession86-10MES/Tilley_A%20MESThesis%202007.pdf.
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Diawuo, Felix. "Water Supply of Accra, with Emphasis on Sachet Water." Thesis, KTH, Vattenförvaltning, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-99333.
Full textAbstract:
This project seeks to assess the impact of the sachet water industry on the health, socio-economic and the environmental situation of the inhabitants of Accra, the capital city of Ghana. In addressing the situation, the driving forces which have fuelled the shift of consum-er taste from the normal tap water and the traditional hand-tied-ice water products to the plastic sachet water (commonly known in as "Pure Water") are identified. Lack of access to continuous flow of improved water and the perceived poor quality of the urban water supply system as results of poor management structure are identified as some of the factors for the shift in consumers’ taste for plastic sachet and bottled drinking water. The quality of the plastic sachet is also assessed through the review of previous research results. These are confirmed by laboratory analysis of about six brands of plastic sachet water and two brands bottled drinking water. The laboratory analysis carried out assessed the microbial, physical and chemical quality of the various samples. To assess the health impacts of the products, the results from the analysis are compared with WHO guideline values and other international guideline values. Questionnaires are also administered to ascertain the socio-economic impacts of the products on the life of the young men and women as well sachet water manufacturers. From this, some measures are suggested as to how to mitigate the activities of the sachet water business to reduce its negative effects on the health, the environment and the socio-economic status of the inhabitants of the city.
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Evans, Lauren G. "Minimizing the Effects of Cement Slurry Bleed-Water on Water Quality Samples." Arizona-Nevada Academy of Science, 1987. http://hdl.handle.net/10150/296377.
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From the Proceedings of the 1987 Meetings of the Arizona Section - American Water Resources Association, Hydrology Section - Arizona-Nevada Academy of Science and the Arizona Hydrological Society - April 18, 1987, Northern Arizona University, Flagstaff, ArizonaSome groundwater monitor wells produce water quality samples with anomalously high pH measurements. In some of these wells it is obvious that these water quality samples are affected by the bleed-water from the cement used to seal the annuli. To gain an understanding as to why cement bleed -water occurs and how it can be controlled, literature from both the cement and petroleum industries are reviewed. Cement is a very alkaline material. When too much water is used to prepare the slurry, alkaline bleed -water can drain through or along the cement sheath surrounding the casing. This results in an increase in the pH measurements of groundwater samples. This bleed-water can separate from the cement in-three ways: it can move into the formation during cementing, it can accumulate within the cement forming pockets and channels behind the casing, and it can remain within the interconnected capillaries that exist throughout the cement sheath. The drainage of alkaline bleed -water from the cement can be greatly reduced by controlling the amount of water used in the preparation of the slurry. The amount of water added can be monitored during well construction by measuring the slurry density. By implementing this quality control procedure during well construction along with specifying the correct amount of mix-water for the slurry, the elevated pH levels in groundwater samples should be greatly reduced if not completely eliminated.
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Haigh, R. A. "Water balance and water quality studies in an underdrained clay soil catchment." Thesis, University of Oxford, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.371543.
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Adeloye, A. J. "Value of river flow data for water resources and water quality assessment." Thesis, University of Newcastle Upon Tyne, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378277.
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English, Ross M. "Legislation for clean water : Congress and the Water Quality Act of 1987." Thesis, Keele University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301457.
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