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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.
471

Evaluation of a Planning Methodology: Integrating Land Use Information in Water Quality Planning

Conover, Matthew B. 01 May 1980 (has links)
The case study investigated was the 208 water quality planning conducted in the Ashley Valley, around Vernal, Utah. The region is expected to urbanize rapidly due to energy development on adjacent state and federal land. The water quality planning was being conducted in the absence of substantial prior land use planning. A method is developed in the thesis for evaluating plans and methodologies. The method utilizes preformulated evaluation criteria to analyze structure and function of the methdology, political context, informational inputs, limiting factors, trigger factors, causeeffect relationships, and impacts of methodology on planning recommendations. The criteria collected from the literature and agency guidelines are consolidated into an evaluation model. Data were collected through field interviews, on-site inspection, and examination of workplans, critical path charts and plan documents. The planning was well conducted overall. However, the water quality planning methodology did not maximize the utilization of land use information, nor did it integrate the available land use information into the analysis as fully as possible. Utilization of land use information could have been increased through greater emphasis on land use in the original workplan, more guidance to staff through specification of land use analysis subtasks, tighter coordination of staff, and consideration of a broader range of alternative scenarios. The cursory nature of the land use analysis limited the number of alternative land use patterns identified. This in turn limited the number of potential pollution sources identified. The local political context discouraged serious consideration of some alternative land use patterns, and the use of land use controls as a management strategy.
472

Examining Water Quality and Human Perception using the Mill Creek in Cincinnati, Ohio, as a Case Study

Bethune, Mackenzie January 2021 (has links)
No description available.
473

Springs in the Central Parts of Vallentuna Municipality - traditions and threats / Källor i centrala Vallentuna - traditioner och hot

Hadodo, Hannan January 2017 (has links)
Twenty springs in the central parts of Vallentuna municipality have been studied to determine their present water qualities and suggest actions that could be taken to improve the water quality and availability of the springs. The measured parameters are the water volume, the water flow, the water temperature, the pH-value, the electrical conductivity, the chloride concentration, the alkalinity and the CODMn. The sensory properties of the springs were also examined, which include odour, colour, clarity and precipitation. Measurements of the water flows, the water temperatures, the pH-values and the electrical conductivities were performed during a field trip in Vallentuna. During this field trip, two water samples were taken from each spring. Thereafter, the alkalinity, the chloride concentration, the CODMn and the sensory properties were determined in the laboratory. Four of the springs, which were wells, have water of high quality and can easily be restored. Some of the twenty springs have not been cared for or have even disappeared. The water from the spring horizon near Arkels tingstad is unfortunately mixed with stormwater, which runs off the nearby roads. This contamination is examined by measuring the chloride flows of the different streams.  The roads also contribute with metal pollution, with metals such as cadmium. Therefore, metal speciations of cadmium were examined. A simple solution is suggested to remove the metal pollution. The measured water flows of all of the spring waters in Vallentuna were quite small. The results of the measurements of the spring waters were compared with the values recommended by Livsmedelsverket and Socialstyrelsen. Most of the values were between the recommended limits for drinking water. Suggestions are given to improve the springs concerning water quality and availability. / Tjugo källor i centrala Vallentuna studerades för att bestämma deras vattenkvalitet och för att föreslå åtgärder i avsikt att förbättra vattenkvaliteten och tillgängligheten av källorna. De mätta parametrarna är vattenvolym, flödeshastighet, vattentemperatur, pH-värde, elektrisk konduktivitet, kloridkoncentration, alkalinitet och CODMn. Dessutom undersöktes källvattnens sensoriska egenskaper, vilka innefattar lukt, färg, klarhet och utfällning. Mätningar av flödeshastigheterna, vattentemperaturerna, pH-värdena och elektriska konduktiviteterna gjordes under en exkursion i Vallentuna. Två vattenprover togs från varje källa. Därefter undersöktes kloridkoncentrationen, alkaliniteten, CODMn och de sensoriska egenskaperna på laboratoriet. Fyra av källorna, vilka var brunnar, har vatten av hög kvalitet och kan relativt enkelt restaureras. En del av de tjugo källorna har inte vårdats under lång tid och har till och med försvunnit. Vattnet från källhorisonten vid Arkels tingstad har olyckligtvis blandats med dagvatten, vilket rinner från de närliggande vägarna. Denna förorening analyseras genom att mäta kloridflödet i olika strömmar. Vägarna bidrar också med metallföroreningar, t.ex. kadmium. Därför har också metallförekomstformer för kadmium modellerats. En enkel metod föreslås för att avlägsna metallföroreningarna. Vattenflödena från källorna i centrala Vallentuna är relativt små.  Resultatet av mätningarna av källvattnen jämfördes med de rekommenderade värdena för dricksvatten enligt Livsmedelsverket och Socialstyrelsen. De flesta värdena låg inom gränserna för de rekommenderade värdena för dricksvatten. Förslag ges till förbättring av källorna med avseende på vattenkvalitet och tillgänglighet.
474

Assessment of Climatic Variability on Water Quality, Quantity, and Crop Productivity in Mississippi Watersheds

Jayakody, Badde VPL 11 May 2013 (has links)
This study was conducted on two Mississippi watersheds. The SWAT model was applied to the Upper Pearl River Watershed (UPRW) to evaluate flow, sediment, nutrients, and fecal coliform bacteria (FCB) transport. The model was further applied to evaluate crop and sediment yields from three tillage systems (Conventional, Reduce 1, and Reduce 2) of the Big Sunflower River Watershed (BSRW). In the UPRW, flow and sediment simulations showed good to very good model performances (for flow R2 up to 0.76 and NSE up to 0.75; and for sediment R2 up to 0.72 and NSE up to 0.54). Both total nitrogen (TN) and total phosphorous (TP) simulations showed fair to good model performances (R2 up to 0.71 and NSE up to 0.63 for TN; R2 up to 0.70 and NSE up to 0.59 for TP). The FCB simulation showed good model performance (R2 up to 0.59 and NSE up to 0.58). In the BSRW, crop simulations showed good to very good model performances (for corn yield R2 up to 0.5 and NSE up to 0.9; and for soybean yield R2 and NSE up to 0.6). Furthermore, modeling outputs of the BSRW explained 64% of the water table fluctuations in the Mississippi alluvial aquifer. The future climates of the UPRW and the BSRW were evaluated for three emission scenarios (A1B, A2, and B1) from the Intergovernmental Panel on Climate Change (IPCC) with the help of the general circulation model, CCSM3. Simulations predict future sediment yields will increase as much as 25% in the UPRW. Both TN and TP yields will also be elevated as much as 7.3% and 14.3% respectively in future climates of the UPRW. Four best management practices (BMPs) were applied to the current and future climates in the UPRW and results showed that BMPs were able to reduce 51% of flow, 55% of sediment, 44% of TN, and 88% of TP in the baseline climate. Moreover, the effectiveness of TN removal will increase in future climates, while the effectiveness of TP removal will remain unchanged. The effects of climate variability on corn and soybean yield were insignificant in the BSRW.
475

Functions of Wetland Plant Assemblages on Water Quality Improvement

Windham, Evelyn Louise 12 August 2016 (has links)
Studies have shown wetlands act as filters for nutrient rich waters, in part due to macrophyte properties. Differences have been found in nitrogen removal rates among plant species in studies of monocultures grown in mesocosms mimicking wastewater treatment constructed wetlands, but little research has been done on assemblages in natural or restored wetlands. This study aims to identify differences in water quality among plant assemblages in natural and restored wetlands. Thirty natural and restored wetlands in the Mississippi portion of the Mississippi Alluvial Valley were sampled four times. Water quality was measured and plant assemblages identified. Significant differences in pH, conductivity, and turbidity were found among four different plant growth forms, but nutrient concentrations were not significantly different among growth forms. Because nutrient concentrations were low, data collected may not have adequately captured potential differences in nutrient concentrations among plant assemblages.
476

Methodology Development for the Measurement and Analysis of Sediment Oxygen Demands and Nutrient Releases

Laurens Vallejo, Luis Alfonso 09 December 2016 (has links)
Sediment oxygen demand (SOD) and nutrients releases from the bottom sediments of a water body are important parameters to be included in studies of water quality processes. Two methods to measure SOD, in situ and at laboratory, were applied at Eckie’s Pond on late spring of 2015. Based upon preliminary results, which showed greater values for the in situ method, some modifications of procedures and equipment were made to improve the measurements. Another set of measurements were made on June of 2016, however their results were not conclusive to establish a correlation between these methodologies. As a result of this research, three standard operating procedures (SOP) have been established to measure SOD at shallow waters, first in situ, second at laboratory, and a third SOP to analyze nutrients and metals by using a spectrophotometer.
477

Effects of Riparian Shade on Nearshore Reservoir Fish Assemblages and Water Quality

Raines, Clayton D 06 May 2017 (has links)
Shade is defined as the coolness and darkness caused by shelter from solar radiation. In freshwater, shade is most commonly provided by riparian vegetation, which can affect water quality through its effects on temperature and light. The purpose of this research was to explore riparian shade influences on (1) fish distribution along reservoir littorals and (2) diel water quality patterns. Sampling was conducted in shaded and non-shaded paired sites in Columbus Lake, Mississippi, U.S.A. Differences in species distribution revealed that, in general, clupeids and most centrarchids were better represented in unshaded sites, while percids were better represented in shaded sites. Diel cycles of water quality variables were measured in situ over 24-h periods with auto-samplers and assessed using trigonometric polynomial regression to describe daily cycles. Analysis of covariance revealed all water quality variables differed between sites and most also varied between shaded and unshaded sites and exhibited daily cycles.
478

Advanced optofluidic sensing and imaging technologies / Advanced optofluidic sensing and imaging devices for onsite monitoring

Xiong, Bo January 2021 (has links)
Water contaminations are currently threatening ecosystems and human health on a world-wide scale. Monitoring the water quality is one of the most essential steps to provide better understanding and mitigation of water contamination. Among the water quality monitoring techniques, optofluidic technologies have created a burgeoning number of novel devices designed to test water quality in an efficient and portable format. However, current optofluidic devices have yet to be successfully translated to onsite monitoring applications due to their high cost, high maintenance and dependence on delicate laboratory instruments or bulky instruments. In this work, we developed two optofluidic platforms for onsite water quality monitoring: a fluorescence-based optofluidic platform for chemical analysis and an imaging-based optofluidic platform for microbe detection. Several technologies associated to optical sensing modules were developed to overcome the above challenges, making the optofluidic platforms compatible with onsite monitoring applications. First, excitation coupling mechanism and frequency domain time-resolved fluorescence (TRF) were developed on the fluorescence-based optofluidic platform to improve sensing sensitivity and stability, while reducing dependence on costly instruments. Their effectiveness was demonstrated by dissolved oxygen (DO) measurements and ray-tracing simulation. Second, a low-cost and portable imaging system with dual modalities were developed on the imaging-based optofluidic platform. Thus, both morphological features and fluorescent features can be observed for microbe detection without using bulky microscope setups. The effectiveness of dual-modality imaging was demonstrated by experimental results of phytoplankton analysis. Third, a fluorescence lifetime imaging (FLIM) approach was developed under a low-cost (Complementary metal–oxide–semiconductor) CMOS format. This approach enables integrating FLIM module in portable optofluidic platforms for onsite monitoring. These advances bring optofluidic platforms closer to realizing the requirements of onsite water quality monitoring and provide a clear picture for future improvements and research directions. / Thesis / Doctor of Philosophy (PhD)
479

Evaluation of the Efficacy of the Stress Protein Response as a Biochemical Water Quality Biomonitoring Method

Dyer, Scott Douglas 05 1900 (has links)
The stress protein response (SPR) is a conserved and ubiquitous mechanism that enables cells to tolerate a wide variety of environmental insults. This response involves the preferential synthesis of an array of proteins with different molecular weights. These proteins perform a variety of functions, such as protein folding, multimeric protein assembly, steroid receptor binding, and heme catabolism. To evaluate the potential use of the SPR as a biomonitoring tool, a stepwise plan was utilized that proceeded through various physical and chemical laboratory exposures and culminated with a field validation study. The goals of the laboratory exposures were threefold: (1) determine the time required for induction of the SPR; (2) determine the dose-responsiveness of the SPR; and (3) compare the increased syntheses and accumulations of stress proteins to classical toxicological endpoints (i.e. percent mortality, LC50, LC1, etc).
480

USING DNA-BASED METHODS TO DETECT AND IDENTIFY FECAL CONTAMINATION SOURCE IN GROUNDWATER TO AUGMENT CULTURE-BASED DETECTION OF FECAL POLLUTION

Naphtali, Paul 18 November 2016 (has links)
Residents in rural communities across Canada rely on groundwater as their main drinking water source, but the private maintenance of this source may increase the risk of fecal contamination caused by human or animal wastes. Wainfleet, a rural Ontario community, has been under an active boil water advisory for the past decade. The last study to assess groundwater quality, performed in 2007, determined that half of the 586 groundwater wells contained exceedances in total fecal coliform and E. coli counts. A critical examination of fecal contamination levels and its sources is not only necessary for maintaining public health in the township, but is also an opportunity to examine the robustness of culture-independent methods for quantifying and sourcing fecal contamination in groundwater environments across Canada. For this project, culture-based and culture-independent methods were utilized to quantify and source any fecal contaminants in Wainfleet’s groundwater. Culture counts of fecal indicator bacteria (FIB) suggested that some of the groundwater wells were receiving more fecal contamination than others, as expected based on a previous study that was conducted 10 years prior. The groundwater wells with higher E. coli counts also had higher read counts of microbes like Campylobacterales which could come from septic tanks and higher concentrations of oxidized nitrogen which can also indicate human-based fecal contamination. Finally, fecal contamination in groundwater wells with E. coli tested positive for the human Bacteroidales marker. Taken together, this study shows that fecal contamination pervades groundwater wells across the boil water advisory zone, much of which originates from leaking septic tanks and poorly-constructed groundwater wells. In this study, we have shown that a suite of protocols, from physiochemical quantification to targeted sequencing and qPCR, can be used to complement culture-based assays in quantifying and pinpointing fecal contamination in groundwater sources. / Thesis / Master of Science (MSc) / Boil water advisories are enacted when fecal contamination levels exceed provincial limits. Standard methods for quantifying fecal contamination use the culture-based detection of fecal indicator bacteria. Sequencing the 16S rRNA gene and amplifying Bacteroidales markers can also be used to identify novel fecal markers and quantify host-specific contaminants in source waters. Using culture and genetic-based methods determined that groundwater wells across Wainfleet, a Niagara township with the longest active boil water advisory in Canada, contain septic tank microbes and are primarily contaminated by leaking septic tanks. Genetic-based assays can complement culture-based detection of fecal bacteria in groundwater sources across Canada.

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