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Haggarty, Ruth Alison. "Evaluation of sampling and monitoring designs for water quality." Thesis, University of Glasgow, 2012. http://theses.gla.ac.uk/3789/.
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Assessing water quality is of crucial importance to both society and the environment. Deterioration in water quality through issues such as eutrophication presents substantial risk to human health, plant and animal life, and can have detrimental effects on the local economy. Long-term data records across multiple sites can be used to investigate water quality and risk factors statistically, however, identification of underlying changes can only be successful if there is a sufficient quantity of data available. As vast amounts of resources are required for the implementation and maintenance of a monitoring network, logistically and financially it is not possible to employ continuous monitoring of all water environments. This raises the question as to the optimal design for long-term monitoring networks which are capable of capturing underlying changes. Two of the main design considerations are clearly where to sample, and how frequently to sample. The principal aim of this thesis is to use statistical analysis to investigate frequently used environmental monitoring networks, developing new methodology where appropriate, so that the design and implementation of future networks can be made as effective and cost efficient as possible. Using data which have been provided by the Scottish Environment Protection Agency, several data from Scottish lakes and rivers and a range of determinands are considered in order to explore water quality monitoring in Scotland. Chapter 1 provides an introduction to environmental monitoring and both existing statistical techniques, and potential challenges which are commonly encountered in the analysis of environmental data are discussed. Following this, Chapter 2 presents a simulation study which has been designed and implemented in order to evaluate the nature and statistical power for commonly used environmental sampling and monitoring designs for surface waters. The aim is to answer questions regarding how many samples to base the chemical classification of standing waters, and how appropriate the currently available data in Scotland are for detecting trends and seasonality. The simulation study was constructed to investigate the ability to detect the different underlying features of the data under several different sampling conditions. After the assessment of how often sampling is required to detect change, the remainder of the thesis will attempt to address some of the questions associated with where the optimal sampling locations are. The European Union Water Framework Directive (WFD) was introduced in 2003 to set compliance standards for all water bodies across Europe, with an aim to prevent deterioration, and ensure all sites reach `good' status by 2015. One of the features of the WFD is that water bodies can be grouped together and the classification of all members of the group is then based on the classification of a single representative site. The potential misclassification of sites means one of the key areas of interest is how well the existing groups used by SEPA for classification capture differences between the sites in terms of several chemical determinands. This will be explored in Chapter 3 where a functional data analysis approach will be taken in order to investigate some of the features of the existing groupings. An investigation of the effect of temporal autocorrelation on our ability to distinguish groups of sites from one another will also be presented here. It is also of interest to explore whether fewer, or indeed more groups would be optimal in order to accurately represent the trends and variability in the water quality parameters. Different statistical approaches for grouping standing waters will be presented in Chapter 4, where the question of how many groups is statistically optimal is also addressed. As in Chapter 3, these approaches for grouping sites will be based on functional data in order to include the temporal dynamics of the variable of interest within any analysis of group structure obtained. Both hierarchical and model based functional clustering are considered here. The idea of functional clustering is also extended to the multivariate setting, thus enabling information from several determinands of interest to be used within formation of groups. This is something which is of particular importance in view of the fact that the WFD classification encompasses a range of different determinands. In addition to the investigation of standing waters, an entirely different type of water quality monitoring network is considered in Chapter 5. While standing waters are assumed to be spatially independent of one another there are several situations where this assumption is not appropriate and where spatial correlation between locations needs to be accounted for. Further developments of the functional clustering methods explored in Chapter 4 are presented here in order to obtain groups of stations that are not only similar in terms of mean levels and temporal patterns of the determinand of interest, but which are also spatially homogenous. The river network data explored in Chapter 5 introduces a set of new challenges when considering functional clustering that go beyond the inclusion of Euclidean distance based spatial correlation. Existing methodology for estimating spatial correlation are combined with functional clustering approaches and developed to be suitable for application on sites which lie along a river network. The final chapter of this thesis provides a summary of the work presented and discussion of limitations and suggestions for future directions.
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Masters, Sheldon. "Lead and Copper Contamination in Potable Water: Impacts of Redox Gradients, Water Age, Water Main Pipe Materials and Temperature." Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/73338.
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Potable water can become contaminated with lead and copper due to the corrosion of pipes, faucets, and fixtures. The US Environmental Protection Agency Lead and Copper Rule (LCR) is intended to target sampling at high-risk sites to help protect public health by minimizing lead and copper levels in drinking water. The LCR is currently under revision with a goal of better crafting sampling protocols to protect public health. This study examined an array of factors that determine the location and timing of "high-risk" in the context of sampling site selection and consumer health risks. This was done using field studies and well-controlled laboratory experiments.
A pilot-scale simulated distribution system (SDS) was used to examine the complex relationship between disinfectant type (free chlorine and chloramine), water age (0-10.2 days), and pipe main material (PVC, cement, and iron). Redox gradients developed in the distribution system as controlled by water age and pipe material, which affected the microbiology and chemistry of the water delivered to consumer homes. Free chlorine disinfectant was the most stable in the presence of PVC while chloramine was most stable in the presence of cement. At shorter water ages where disinfectant residuals were present, chlorine tended to cause as much as 4 times more iron corrosion when compared to chloramine. However, the worst localized attack on iron materials occurred at high water age in the system with chloramine. It was hypothesized that this was due to denitrification-a phenomenon relatively unexplored in drinking water distribution systems and documented in this study.
Cumulative chemical and biological changes, such as those documented in the study described above, can create "high-risk" hotspots for elevated lead and copper, with associated concerns for consumer exposure and regulatory monitoring. In both laboratory and field studies, trends in lead and copper release were site-specific and ultimately determined by the plumbing material, microbiology and chemistry. In many cases, elevated levels of lead and copper did not co-occur suggesting that, in a revised LCR, these contaminants will have to be sampled separately in order to identify worst case conditions.
Temperature was also examined as a potentially important factor in lead and copper corrosion. Several studies have attributed higher incidence of childhood lead poisoning during the summer to increased soil and dust exposure; however, drinking water may also be a significant contributing factor. In large-scale pipe rigs, total and dissolved lead release was 3-5 times higher during the summer compared to the winter. However, in bench scale studies, higher temperature could increase, decrease, or have no effect on lead release dependent on material and water chemistry. Similarly, in a distribution system served by a centralized treatment plant, lead release from pure lead service lines increased with temperature in some homes but had no correlation in other homes. It is possible that changes throughout the distribution system such as disinfectant residual, iron, or other factors can create scales on pipes at individual homes, which determines the temperature dependency of lead release.
Consumer exposure to lead can also be adversely influenced by the presence of particulate iron. In the case of Providence, RI, a well-intentioned decrease in the finished water pH from 10.3 to 9.7, resulted in an epidemic of red water complaints due to the corrosion of iron mains and a concomitant increase in water lead levels. Complementary bench scale and field studies demonstrated that higher iron in water is sometimes linked to higher lead in water, due to sorption of lead onto the iron particulates.
Finally, one of the most significant emerging challenges associated with evaluating corrosion control and consumer exposure, is the variability in lead and copper during sampling due to semi-random detachment of lead particles to water, which can pose an acute health concern. Well-controlled test rigs were used to characterize the variability in lead and copper release and compared to consumer sampling during the LCR. The variability due to semi-random particulate detachment, is equal to the typical variability observed in LCR sampling, suggesting that this inherent variability is much more important than other common sources including customer error, customer failure to follow sampling instructions or long stagnation times. While instructing consumers to collect samples are low flow rates reduces variability, it will fail to detect elevated lead from many hazardous taps. Moreover, collecting a single sample to characterize health risks from a given tap, are not adequately protective to consumers in homes with lead plumbing, in an era when corrosion control has reduced the presence of soluble lead in water. Future EPA monitoring and public education should be changed to address this concern.<br>Ph. D.
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De, Schaetzen Werner. "Optimal calibration and sampling design for hydraulic network models." Thesis, University of Exeter, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.322278.
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Alvarez, David A. "Development of an integrative sampling device for hydrophilic organic contaminants in aquatic environments /." free to MU campus, to others for purchase, 1999. http://wwwlib.umi.com/cr/mo/fullcit?p9962500.
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Di, Bonito Marcello. "Trace elements in soil pore water : a comparison of sampling methods." Thesis, University of Nottingham, 2005. http://eprints.nottingham.ac.uk/10123/.
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This thesis examined a range of methods for sampling soil pore water to investigate the chemistry of trace elements. In particular, the study assessed whether Rhizon samplers, centrifugation, high pressure squeezing and soil suspensions in simulated pore water can be viable approaches for obtaining representative samples of equilibrated soil pore water. Results for metal solubility and speciation were interpreted in terms of both soil morphological effects on trace metal dynamics and artefacts introduced at various stages during sample preparation and handling. The main soil used in the study was an organic-rich sandy silt from a site which has served as a sewage re-processing facility for almost a century. This soil was chosen because of its importance as a long-term repository for metal-enriched sludge applied to arable land, providing a suitable medium on which to study trace metal behaviour. Pore waters were extracted and analysed for major and trace cations and anions, pH, Dissolved Inorganic Carbon (DIC) and Dissolved Organic Carbon (DOC) at two different temperatures (5 degrees Celsius and 15 degrees Celsius), in order to evaluate the extent of bacterial activity, organic decomposition and their consequences on solute composition, during pore water extractions. Speciation was estimated from analysis of pore water chemistry using two software packages (PHREEQCi and WHAM-VI). Pore waters showed different ranges of concentration between the various methods. Different mechanisms and/or chemical reactions were involved during the different extractions; a range of processes was identified, mainly dominated by metal complexation by humus acids and redox reactions. Results revealed that the soil studied was able to partially buffer the free ion activities of the metal ions in pore water with increasing dilutions, but demonstrated virtually no ability to buffer DOC. Identification of the source (i.e. location of pore space) of water extracted was also investigated using water with different isotopic composition (18O/16O). Evidence showed that centrifugation was not able to differentiate between more and less mobile water at FC conditions, rather enhancing the mixing between the two pools of water (native and labelled) by and apparent process of 'infusion'. By contrast, Rhizon samplers appeared to sample water preferentially from the more accessible pool (extra-aggregate), which proved to have a composition showing incomplete mixing with the native water. The results also suggested that mixing of the two pools was rather fast and that was almost completely attained prior to pore water extraction. The study established that the most important factors affecting pore water chemistry during extraction are the conditions to which the samples are exposed during the extraction process. For these reasons Rhizon samplers should be used as a disposable device, and are only applicable for use in high soil moisture soil contents. In contrast, they present no 'side-effects' (providing enough equilibration time) if M2+ (free ion activity) were needed as opposed to Msol (total metal concentration in pore water), as often required in environmental studies. Centrifugation is optimal for bulk solution studies, or when homogenisation represents a key experimental point; targeted studies are also possible. Soil squeezing is subject to severe limitations in the case of prolonged extractions of biologically active soils, due to the effects of anaerobism. Squeezing should only be used for 'fast' extractions of soils. Finally, batch extractions are well suited to studies on M2+ equilibria, but more studies are needed to clarify the effect of soil: solution ratio on metal and DOC solubility.
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Alsanabani, Mohamed Moslih. "Soil water determination by time domain reflectometry: Sampling domain and geometry." Diss., The University of Arizona, 1991. http://hdl.handle.net/10150/185550.
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This work investigates several aspects of time domain reflectometry (TDR) theory and application. One of these aspects is the study of the influence of TDR probe geometries on the travel time. No change in the travel time resulted from increasing either the diameter of wire or spacing. However, we found a linear relationship between the travel time and the length of the probe for measurements in water. Also we found the reflected voltage was inversely proportionally to the incident voltage in water. Another aspect is the volume of sensitivity for the TDR which depends on the electrical properties of the medium and the geometry of the probe. The sensitivity of TDR in soil is different than in water. The observations in soils indicate that soil with a high water content (θᵥ) has a smaller sample volume than the one with low θᵥ. A probe with a large wire diameter has a larger sample volume than a probe with a small wire diameter. Also, a simple model and a mixing model were investigated and compared to Topp's model, for relating θᵥ to the effective dielectric constant. The distance to wetting front over time was observed and calculated using an expression which relates the travel time in soil before and after water application. This was tested with probes of different geometries. The wetting front from a point source were monitored for two and three dimensions in a plexiglas tank using TDR. Contour maps for the calculated radius of wetting front vs. the depth over time were produced.
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Kapelan, Zoran. "Calibration of water distribution system hydraulic models." Thesis, University of Exeter, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370011.
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A number of mathematical models are used nowadays to describe behaviour of the reallife water distribution system (WDS). It is a well known fact that, to have any meaningful use, any WDS mathematical model must be calibrated first. Here, calibration is defined as process in which a number of WDS model parameters are adjusted until the model mimics behaviour of the real WDS as closely as possible. In this thesis, WDS mathematical models that are used to model water quantity aspect only are analysed. Three hydraulic models considered here are: (1) steady-state flow model, (2) quasi-steady flow (extended period simulation) model and (3) unsteady flow model. The calibration problem analysed here is formulated as a constrained optimisation problem of weighted least square type with the objective defined in a way that enables effective incorporation of prior information on calibration parameters. WDS calibration problem is then analysed in detail, including special issues of identifiability, uniqueness and stability of the problem solution. A list of diagnostic and other statistics and analysis is presented to improve existing calibration approaches by providing partial insight into the calibration process. Calibration of WDS hydraulic models is further improved by the development of new hybrid optimisation method. Being closely related to calibration, the problem of sampling design for calibration of WDS hydraulic models is also addressed here. First, sampling design is formulated as a constrained two-objective optimisation problem. Then, two novel models are developed to solve it. The first model is based on standard, single-objective Genetic Algorithms (SOGA). The second model is based on multi-objective Genetic Algorithms (MOGA). Finally, all novel methodologies presented here are verified successfully on multiple case studies that involve both artificial and real-life WDS. At the end, relevant conclusions are drawn and suggestions for further research work are made.
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Wei, Jian. "Microcolumn field sampling and flow injection techniques for mercury speciation." Thesis, Sheffield Hallam University, 1993. http://shura.shu.ac.uk/20513/.
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Mercury is one of the most toxic heavy metals, and many serious incidents have resulted from mercury poisoning. The methylation of mercury and its amplification by marine life have aggravated this pollution problem. Studies over the last three decades have shown that the toxicity of mercury is related to chemical form. A basic aim of the research has been to devise new methodology for the measurement and speciation of mercury. Key points of the investigation reported were the literature review of methodologies and techniques for mercury speciation and the development of a novel manifold which incorporates microcolumns of sulphydryl cotton which have a relatively high affinity and selectivity for inorganic and / or organomercury, and to utilise a continuous flow procedure for mercury speciation based on flow injection-atomic fluorescence spectrometry. This new and novel system has been used for the determination and speciation of mercury in a variety of water samples. The other column packing materials, eg. xanthate cotton, activated alumina and 8-hydroxy-quiniline were also investigated. A further aspect of element speciation concerns the development of a field sampling technique using sulphydryl cotton columns. Sample collection and preconcentration using microcolumns at the site of sampling was successfully performed. Preliminary experiments indicated that the field sampling technique in combination with FIA-AFS was a robust and potentially useful speciation tool. Field surveys on mercury distribution and speciation in the Manchester Ship Canal and the River Rother have been intensively carried out in collaboration with the National Rivers Authority (North West Region). The analytical data on different mercury species in waters of the Manchester Ship Canal are reported for the first time. A high correlation between organomercury and organolead in the Manchester Ship Canal is found and the related data have been assessed in order to clarify the possible origins for organomercury. Related work concerning participation in interlaboratory studies is reported in the Appendices.
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Bookwalter, Candice Anne. "CONTINUOUS SAMPLING IN MAGNETIC RESONANCE IMAGING." Case Western Reserve University School of Graduate Studies / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=case1194049081.
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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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Rana, SM Masud. "Contaminant Spread Forecasting and Sampling Location Identification in a Water Distribution Network." University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1383909255.
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Sumer, Derya. "Impact of Data Collection and Calibration of Water Distribution Models on Model-Based Decisions." Diss., The University of Arizona, 2007. http://hdl.handle.net/10150/194892.
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Mathematical models of water distribution systems (WDS) serve as tools to represent the real systems for many different purposes. Calibration is the process of fine tuning the model parameters so that the real system is well-represented. In practice, calibration is performed considering all information is deterministic. Recent researches have incorporated uncertainties caused by field measurements into the calibration process. Parameter (D-optimality) and predictive (I-optimality) uncertainties have been used as indicators of how well a system is calibrated.This study focuses on a methodology that extends previous work by considering the impact of uncertainty on decisions that are made using the model. A new sampling strategy that would take into account the accuracy needed for different model objectives is proposed.The methodology uses an optimization routine that minimizes square differences between the observed and model calculated head values by adjusting the model parameters. Given uncertainty in measurements, the parameters from this nonlinear regression are imprecise and the model parameter uncertainties are computed using a first order second moment (FOSM) analysis. Parameter uncertainties are then propagated to model prediction uncertainties through a second FOSM analysis. Finally, the prediction uncertainty relationships are embedded in optimization problems to assess the effect of the uncertainties on model-based decisions. Additional data is collected provided that the monetary benefits of reducing uncertainties can be addressed.The proposed procedure is first applied on a small hypothetical network for a system expansion design problem using a steady state model. It is hypothesized that the model accuracy and data required calibrating WDS models with different objectives would require different amount of data. A real-scale network for design and operation problems is studied using the same methodology for comparison. The effect of a common practice, grouping pipes in the system, is also examined in both studies.Results suggest that the cost reductions are related to the convergence of the mean parameter estimates and the reduction of parameter variances. The impact of each factor changes during the calibration process as the parameters become more precise and the design is modified. Identification of the cause of cost changes, however, is not always obvious.
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Anderson, Cody Allen. "Permeation Sampling of BTEX and Gasoline." University of Akron / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=akron1279115371.
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Leitch, Katherine McArthur. "Estimating Tributary Phosphorus Loads Using Flow-Weighted Composite Storm Sampling." Thesis, Virginia Tech, 1998. http://hdl.handle.net/10919/10078.
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Quantification of total phosphorus (TP) loads entering a lake or reservoir is important because phosphorus is most often the limiting nutrient in terms of algae growth, thus phosphorus can control the extent of eutrophication. Four methods for assessing the annual tributary phosphorus loads to two different Virginia reservoirs were analyzed, three methods that use tributary monitoring program data and one that uses land-use and rainfall data. In this project, one tributary has been extensively monitored for many years and served as a control on which the other methods were tested. The key difference between this research and previous studies is the inclusion of flow-weighted composite storm sampling instead of simple grab sample analyses of storm flow. Three of the methods employed flow stratification, and the impact of the base flow separation point was examined. It was found that the Regression Method developed in this research was the least sensitive to the base flow separation point, which is a valuable attribute because a wrong choice will not significantly affect the estimate. The Monte Carlo Method was found to underestimate the TP loads. The amount of rainfall impacted the accuracy of the methods, with more error occurring in a year with lower precipitation.<br>Master of Science
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Reid, Sally Elizabeth. "A geochemical study of water-sediment interactions in a freshwater stream environment (Brampton Brook, Cambridgeshire)." Thesis, Anglia Ruskin University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327468.
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Toranzos, Soria Gary Antonio. "Development of a method for the concentration of rotaviruses from water and its application to field sampling." Diss., The University of Arizona, 1985. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_e9791_1985_349_sip1_w.pdf&type=application/pdf.
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Uhlman, Kristine, and Janick Artiola. "Nitrate Contamination Potential in Arizona Groundwater: Implications for Drinking Water Wells." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2011. http://hdl.handle.net/10150/156932.
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4 pp.<br>This fact sheet is to be taken from research conducted by Uhlman and Rahman and published on the WRRC web site as: "Predicting Ground Water Vulnerability to Nitrate in Arizona". Funded by TRIF and peer reviewed by ADEQ. It also follows on "Arizona Well Owner's Guide to Water Supply" and also "Arizona Drinking Water Well Contaminants" (part 1 already submitted, part 2 in process).<br>Arizona's arid environment and aquifer types allow for the persistence of nitrate contamination in ground water. Agricultural practices and the prevalence of septic systems contributes to this water quality concern, resulting in nitrate exceeding the EPA Maximum Contaminant Level (MCL) in several locations across the state. Working with known nitrate concentrations in 6,800 wells across the state, this fact sheet presents maps showing the probability of nitrate contamination of ground water exceeding the MCL. The importance of monitoring your domestic water supply well for nitrate is emphasized.
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Amutis, Rikki Lynn 1958. "An unsaturated fractured rock sampling technique by in situ thermoelectric condensation of water vapor." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/191953.
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Water vapor in the airspace of an unsaturated fractured rock may be sampled by reduction of the air temperature of the medium to its dew point and retrieval of the condensed liquid sample. The required temperature Change was generated in this research by a thermoelectric cooling module, which operates according to the Peltier cooling effect. Laboratory studies of this technique involved the development of the module’s heat sink system and calibration of the instrument for cooling temperatures and condensation rates obtained by variations in the applied current. Temperature and vapor density Changes produced in the air space surrounding the instrument when operated in a moist environment were also evaluated. Field studies performed in an unsaturated, fractured, densely-welded tuff have shown the instrument to be capable of vapor collection, although at a rate lower than that established under laboratory conditions. Applications of this technique include evaluation of oxygen and hydrogen isotopes of moisture in unsaturated media and travel time studies of flow through the unsaturated zone using isotopes as tracers.
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Defenbaugh, Angela Lynn. "Evaluating Ohio River Basin Waters: A Water Quality and Water Resources Internship with the Ohio River Valley Water Sanitation Commission." Miami University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=miami1389295851.
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Longsmith, Rebecca Johnson. "A BIOLOGICAL MONITORING INTERNSHIP WITH THE OHIO ENVIRONMENTAL PROTECTION AGENCY, DIVISION OF SURFACE WATER." Miami University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=miami1451932666.
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Lin, Daorui. "Global Sensitivity of Water Quality Modeling in the Gulf of Finland." Thesis, KTH, Mark- och vattenteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-180285.
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The Gulf of Finland is the most eutrophied water body in the Baltic Sea, which is mainly caused by nutrient loads produced by human activities in its surrounding cities. In order to solve this environmental problem, a computational model based on the understanding the relations between eutrophication, water quality and sediments is needed to forecast the water quality variance in response to the natural and anthropogenic influences. A precise water quality model can be useful to assist the policy making in the Gulf of Finland, and even for the whole Baltic Sea. Kiirikki model, as one of these models describing the water quality of Baltic Sea in response of water quality variance, is a sediment and ecosystem based model, treating different sub-basins and layers as boxes. This study aims to assess the parameters’ sensitivity level on the scale of the Gulf of Finland. Firstly, the Morris sampling strategy is applied to generate economic OAT (One factor At a Time) samples before screening 50 out of 100 trajectories with distance as large as possible. In order to assess their sensitivity, index and indicator are needed. EE (elementary effect) is adopted to be the assessment index and four core eutrophication indicators from HELCOM 2009a are to be analyzed. By comparing the (σ,μ) and (σ,μ*) plots of each parameters’ EE values (σ is standard deviation, μ is mean value and μ* is the absolute mean value), some parameters are identified as potential sensitive parameter, such as the minimum biomass of cyanobacteria (Cmin), critical point of CO2 flux (CCr), the optimal temperature for detritus phosphorous mineralization (Toptgamma), maximum loss rate of algae (RAmax), optimal temperature for the growth of other algae (ToptmuA), Coefficient for temperature limiting factor for the growth of cyanobacteria (aTmuC), half-saturation coefficient of radiation for cyanobacteria (KIC) and so on. In contrast, the other parameters are ruled out as having very low values in terms of σ, μ and μ*. This is because the feature of Morris sampling strategy makes it easier to achieve high variance of the outputs, resulting into generally higher σ. Therefore, further investigation with different strategies is needed after the initial screening of the non-sensitive parameters in this study.
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MacKnight, Eric. "An Autonomous, On-Site Sampling / Analyzing System for Measuring Heavy Metal Ions in Ground Water." University of Cincinnati / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1226769402.
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Lundqvist, Carolina. "Riskbaserat provtagningsprogram för mikroorganismer i Gäddviks vattentäkt." Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-45569.
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Risk-based sampling program of microorganisms in the water source in northern Sweden After several disease outbreaks caused by parasites in the drinking water during the last years, it is more essential than ever to insure that the water supply companies have enough barriers to counteract the presence of microorganisms in the outgoing water. It is also discussed whether climate changes such as increased precipitation can have a connection to the increased cases of parasites in water sources. The water source at Gäddvik is Luleå municipality’s largest and provides drinking water to 64 500 of Luleå’s 74 000 inhabitants. The investigation of microorganisms in the water source, especially in the Lule River has not been as prioritized as the sampling of chemical parameters. Therefore a risk-based sampling program of microorganisms has been established. After analyzing former tests both on the Lule River and the wells at the water supply companies, and observing the precipitation variability over the last 40 years, a sampling program was developed. Analyzes of the chemical parameters from the river have not revealed any significant changes during the sampling time. The precipitation has shown an increasing trend over the past 40 years. The sampling program was divided into three groups containing the parasites Cryptosporidium and Giardia, some indicator organisms (Escherichia coli, coliforms and Clostridium perfringens) and phytoplankton. The infiltration time during the artificial recharge is too short and therefore it is necessary to expand the Standard control for microorganism in the wells (from 12 to 24 samples). The sampling frequency for parasites should be higher during days with heavily rainfall and during the spring flood.
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Parks, Jeffrey L. "Sorption of Boron and Chromium Onto Solids of Environmental Significance: Implications for Sampling and Removal in Water Treatment." Diss., Virginia Tech, 2005. http://hdl.handle.net/10919/29510.
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The chemistry, analysis, treatment, and occurrence of boron and chromium are of high interest since they are under consideration for revised MCLs in potable water. As a starting point to guide regulatory decision-making, a comprehensive review of boron in relation to potable water was undertaken. That work demonstrated that there were not proven cost-effective options for boron treatment.
In preparation for a national survey of boron and chromium occurrence, it was discovered that existing analytical protocols sometimes '"missed" much of the total chromium that was present in water. It was determined that this was due to incomplete dissolution of particulates during routine Standard Method analysis of drinking water at pH 2.0. A more rigorous hydroxylamine digestion was developed and applied to circumvent this limitation.
In relation to treatment, it was determined that sodium carbonate softening at pH 10.3 is a viable method of removing various inorganic contaminants including chromium from drinking water sources. The nationwide survey revealed that removals varied widely and were dependent on solution composition. Median removal of chromium was 92%. Linear and nonlinear empirical models were fit to crudely estimate the removal of various contaminants in the presence of other elements that are typically removed in the softening process (i.e. calcium, magnesium, silicon, iron, and aluminum). Boron was removed to a much lesser extent (median removal 2%) in this study, consistent with the general result of the literature review that enhanced treatments will be required for this contaminant.
Modified precipitative softening was examined as a potentially attractive option to remove boron from natural waters. It was discovered that in some cases when magnesium and silicon were present, and if the pH was 10.8 ± 0.2, very high levels of boron removal (up to 90%) could be achieved versus 10% typically observed for conventional processes. This can be exploited to remove boron in waters naturally containing high levels of magnesium and silicon, or by adding supplemental amounts of either magnesium or silicon when one constituent is deficient.<br>Ph. D.
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Montesino, Malmberg Martina, and Rebecka Olofsson. "An Inventory of the Waste Disposal Site Jhumjhumpur in Jessore, Bangladesh, via Soil and Water Sampling." Thesis, KTH, Skolan för kemivetenskap (CHE), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-207104.
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The aim of this study was to make an inventory of the open dumping site Jhumjhumpur in Jessore, Bangladesh, in order to investigate whether spreading of heavy metals had occurred to surrounding soil and groundwater. The study is based on a thorough literature study as well as a field study, including soil and groundwater sampling, at the dumping site Jhumjhumpur. The literature study covers the current waste management system in three cities of Bangladesh: Dhaka, Jessore and Khulna. The results from the field study indicate that metals from the dumping site have been transported and spread to the groundwater in connection to the site and the agricultural land south of the site. A more complete investigation is needed to be able to determine how big a risk the open dumping site is for the surrounding environment. Measurements for avoiding further contamination of the groundwater and the agricultural land should be implemented.
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Farhadi, Leila. "Estimation of land surface water and energy balance flux components and closure relation using conditional sampling." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/70757.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2012.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (p. 348-364).<br>Models of terrestrial water and energy balance include numerical treatment of heat and moisture diffusion in the soil-vegetation-atmosphere continuum. These two diffusion and exchange processes are linked only at a few critical points. The performance and sensitivity of models are highly dependent on the nature of these linkages that are expressed as the closure function between heat and moisture dynamics. Land response to radiative forcing and partitioning of available energy into sensible and latent heat fluxes are dependant on the functional form. Since the function affects the surface fluxes, the influence reaches through the boundary layer and affects the lower atmosphere weather. As important as these closure functions are, they remain essentially empirical and untested across diverse conditions. It is critically important to develop observation-driven estimation procedures for the terrestrial water and energy closure problem, especially at the scale of modeling and with global coverage. In this dissertation a new approach to the estimation of key unknown parameters of water and energy balance equation and their closure relationship is introduced. This approach is based on averaging of heat and moisture diffusion equations conditioned on land surface temperature and moisture states respectively. The method is derived only from statistical stationarity and conservation statements of water and energy and thus it is scale free. The aim of this dissertation is to establish the theoretical basis for the approach and perform a global test using multi-platform remote sensing measurements. The feasibility of this approach is demonstrated at point-scale using synthetic data and flux-tower field site data. The method is applied to the mesoscale region of Gourma (West Africa) using multi-platform remote sensing data. The retrievals were verified against tower-flux field site data and physiographic characteristics of the region. The approach is used to find the functional form of the Evaporative Fraction (ratio of latent heat flux to sum of latent and sensible heat fluxes) dependence on soil moisture. Evaporative Fraction is a key closure function for surface and subsurface heat and moisture dynamics. With remote sensing data the dependence of this function on governing soil and vegetation characteristics is established.<br>by Leila Farhadi.<br>Ph.D.
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Lee, Alexis J. "Theoretical Approaches to the Characterization of Water, Aqueous Interfaces, and Improved Sampling of Protein Conformational Changes." ScholarWorks@UNO, 2012. http://scholarworks.uno.edu/td/1511.
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Methods to advance the understanding of water and other aqueous systems are devel- oped. This work falls into three areas: The creation of better interaction potentials for water, improved methods for sampling configurational space, and the applications of these methods to understand systems of interest. Charge transfer has been shown by ab initio methods to be important in the water–water and water–ion interactions. A model for treating charge transfer in liquid water and aqueous systems is presented in this manuscript. The model is called Discrete Charge Transfer (DCT) and is based on the commonly-used TIP4P/2005 model, which represents the charge distribution of water molecules with three charge sites. Such models have been very successful in reproducing many of the physical properties of water. Charge transfer is introduced by transferring a small amount of charge, -0.02e, from the hydrogen bond acceptor to the hydrogen bond donor, as has been indicated by electronic structure calculations. We have parameterized both polarizable and non-polarizable potentials, optimized to include charge transfer. Methods to surmount the obstacles incurred by the introduction of charge transfer, which involve the amount of charge transfer at large distances and implementation into Molecular Dynamics simulation, is presented, along with our results assessing the importance of charge transfer in liquid water and aqueous systems. Also presented is a method for improving eciency of a sampling technique, Replica Exchange, by reducing the number of replicas. The improved method is called Replica Exchange with Driven Scaling (REDS2).
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Speakman, Anne Kathryn. "A WATER QUALITY INTERNSHIP WITH THE OHIO ENVIRONMENTAL PROTECTION AGENCY’S DIVISION OF SURFACE WATER." Miami University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=miami1417012918.
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Achanta, Srinivasa G. "Iron oxidation coupled with biodegradation of organic contaminants in a simulated ground water system." Thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-08182009-040235/.
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Franz, Peter. "The isotopic composition of water vapor in the upper troposphere, lower stratosphere region modeling, analysis and sampling /." [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=974085308.
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Apell, Jennifer Nicole. "Using polyethylene passive sampling to assess transport of polychlorinated biphenyls (PCBs) between contaminated sediments, water, and biota." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/113473.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2017<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references.<br>Polychlorinated biphenyls (PCBs), which were a widely used group of chemicals before their manufacture was banned in 1979 in the United States, still contaminate numerous aquatic systems. Although there are ongoing efforts to remediate these sites, our ability to implement effective remediation strategies has been hindered by a limited understanding of how PCBs are transported in the environment as well as how they bioaccumulate into aquatic animals. Investigations of contaminated sites often rely on sediment measurements since PCB concentrations are highest in the sediment phase. However, previous research has shown that sediment concentrations are a poor predictor of contaminant fate and effects, whereas freely dissolved water concentrations were able to predict the extent of bioaccumulation and the onset of toxicological effects more accurately.<br>Additionally, the concentration gradient between the porewater (i.e., the interstitial water in sediment beds) and the overlying water is thought to be a major driver in PCB transport from the sediment bed. Passive samplers, which are made of polymers like polyethylene (PE), accumulate PCBs when they are deployed into environmental media, can be used to estimate freely dissolved water concentrations. When used in the laboratory by mixing with sediment samples, they provide a measure of the sediment-water equilibrium porewater concentration. When deployed in the field, they can provide measures of the in situ porewater and overlying water concentrations. In this work, PE samplers were deployed at two Superfund sites contaminated with PCBs to investigate if in situ porewater and sediments were at equilibrium with each other.<br>In situ porewater concentrations were consistently found to be lower than equilibrium concentrations at both sites, an effect that was likely caused by water flow through the sediment bed. At one of the sites, measurements of a geochemical tracer also showed that the exchange of porewater with overlying water was occurring and that the transport of PCBs from sediments was affected by more than just the concentration gradient. Lastly, the sorptive disequilibria between environmental media and the spatial heterogeneity of contamination were shown to affect the extent of bioaccumulation in aquatic animals at one of the sites.<br>by Jennifer Nicole Apell.<br>Ph. D.<br>Ph.D. Massachusetts Institute of Technology, Department of Civil and Environmental Engineering
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Lindsey, Melanie. "Sampling Frequency for Semi-Arid Streams and Rivers: Implications for National Parks in the Sonoran Desert Network." Thesis, The University of Arizona, 2010. http://hdl.handle.net/10150/193445.
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In developing a water quality monitoring program, the sampling frequency chosen should be able to reliably detect changes in water quality trends. Three datasets are evaluated for Minimal Detectable Change in surface water quality to examine the loss of trend detectability as sampling frequency decreases for sites within the National Park Service's Sonoran Desert Network by re-sampling the records as quarterly and annual datasets and by superimposing step and linear trends over the natural data to estimate the time it takes the Seasonal Kendall Test to detect trends of a specific threshold. Wilcoxon Rank Sum analyses found that monthly and quarterly sampling consistently draw from the same distribution of trend detection times; however, annual sampling can take significantly longer. Therefore, even with a loss in power from reduced sampling, quarterly sampling of Park waters adequately detects trends (70%) compared to monthly whereas annual sampling is insufficient in trend detection (30%).
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Clare, Evan. "DECOMPOSING A WATERSHED’S NITRATE SIGNAL USING SPATIAL SAMPLING AND CONTINUOUS SENSOR DATA." UKnowledge, 2019. https://uknowledge.uky.edu/ce_etds/87.
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Watershed features, physiographic setting, geology, climate, and hydrologic processes combine to produce a time-variant nutrient concentration signal at the watershed outlet. Anthropogenic influences, such as increased agricultural pressures and urbanization, have increased overall nutrient loadings delivered to the fluvial network. The impact of such increased nutrient loadings on Kentucky’s drinking water remains a potential threat to the region.
By coupling spatial sampling of nitrate concentrations in surface water with contemporary nutrient and water quality sensor technology, a decomposition of the Upper South Elkhorn watershed’s nitrate signal and an estimation of source timing and loading in the watershed was completed. The goal of the project was the decomposition of the integrated nitrate signal observed at the outlet of the Upper South Elkhorn watershed into contributing runoff and groundwater sources from agricultural/pasture and urban/suburban land-uses.
Decomposing the watershed’s nitrate signal yielded new knowledge learned about nitrate source, fate and transport in immature fluviokarst. This thesis discusses how mean, seasonal, and fluctuating nitrate behavior is related to soil processes, groundwater transfer, streambed removal, and event dynamics. It is expected that the decomposition of the nitrate signal will allow for the targeting of both the timing and sources for nutrient reductions in a watershed.
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Salley, Dara C. "Evaluation of an on-line extraction, real-time detection sampler and application to environmental sampling of Syracuse, NY drinking water for atrazine." Thesis, State University of New York Col. of Environmental Science & Forestry, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=1568948.
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<p> MONITOR is an active, automatic extraction sampler that collects daily, integrated extracts of hydrophobic compounds in water. Compounds partition from water, through a polydimethylsiloxane membrane and into hexane. The sampling rate, membrane-water partition coefficients (K<sub>MW</sub>) and hexane-water partition coefficients (K<sub>HW</sub>) were determined for atrazine and four nonpolar reference compounds. The reference compounds had high effective sampling rates (>10 L/day) while atrazine had a low effective sampling rate (<1 L/day). Atrazine had intermediate hydrophobicity as determined by K<sub>MW</sub> and octanol-water partition coefficient (KOW). However, atrazine had a low K<sub>HW</sub>, which caused its low sampling rate. In spite of MONITOR's low sampling rate for atrazine, the concentration of atrazine in the drinking water of Syracuse, New York was observed from March - November 2012 using MONITOR. The average concentration was 0.016 μg/L. MONITOR was able to capture fluctuations in the concentration of atrazine at very low levels over several months.</p>
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Coxe, Paul Cameron. "An Examination of Hepatitis A Virus on Working Surfaces in a Waste Water Treatment Plant." University of Toledo / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1533208035412584.
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Lerner, Moriah I. "An Analysis of Heavy Metals in Sediment and Water of Southwestern Costa Rican Watersheds Using ICP-MS." Scholarship @ Claremont, 2015. http://scholarship.claremont.edu/scripps_theses/569.
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Heavy metals can serve as a significant component of pollution in watersheds. In this study, ICP-MS analysis was used to determine the heavy metal content (Cd, Cr, Cu, Mn, Pb, and U) in water and sediment of three different Costa Rican watersheds: the Tarcoles River, the Terciopelo Creek, and the Cacao Creek. While the metal content of each the Terciopelo Creek and Cacao Creek was expected to be lower than that of the Tarcoles River, the results showed that this held true only for Cr and Pb. Elevated levels of the other four metals (Cd, Cu, Mn, and U) in the Terciopelo and Cacao Creeks are likely due to natural, lithogenic origin instead of anthropogenic input.
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Graves, Alexandria Kristen. "Identifying Sources of Fecal Pollution in Water as Function of Sampling Frequency Under Low and High Stream Flow Conditions." Diss., Virginia Tech, 2003. http://hdl.handle.net/10919/27162.
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Sources of fecal pollution were evaluated as a function of sampling frequency with stream samples from Mill Creek, Montgomery County, VA. Samples were collected monthly for one year, plus weekly for four consecutive weeks during seasonal high flows (March), and seasonal low flows (September-October), plus daily for seven consecutive days within the weekly schedules. Thirty stream samples were collected from each of two sites (60 total) in Mill Creek, and 48 isolates of E. coli per sample (total of 2,880 stream isolates) were classified by source using antibiotic resistance analysis (ARA) and comparing the resulting patterns against a known-source E. coli library (1,158 isolates). The same process was performed with enterococci isolates against an enterococci library (1,182 isolates). The average rate of correct classification (ARCC) for the E. coli library with a three-way split (human, livestock, and wildlife) was 89.0%, and the ARCC of the species-specific E. coli library (cattle, deer, goose, human, misc. wildlife) was 88.9%. The ARCC of the enterococci library with a three-way split was 85.3%, and the ARCC of the species-specific enterococci library was 88.1%. The results did not justify the need for daily or weekly sampling, but indicated that monthly was adequate (quarterly and every-other-month were not). There was a seasonal effect as the human signature was highest during high flow while the livestock signature dominated during low flow. The results also indicated that sampling should be done over a period of time that includes both seasonal wettest and driest periods (at least 8 months).<br>Ph. D.
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Pence, Rachel Anabel. "Comparison of Quantitative and Semi-Quantitative Assessments of Benthic Macroinvertebrate Community Response to Elevated Salinity in central Appalachian Coalfield Streams." Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/86787.
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Anthropogenic salinization of freshwater is a global concern. In freshwater environments, elevated levels of major ions, measured as total dissolved solids (TDS) or specific conductance (SC), can cause adverse effects on aquatic ecosystem structure and function. In central Appalachia, eastern USA, studies largely rely on Rapid Bioassessment Protocols with semi-quantitative sampling to characterize benthic macroinvertebrate community response to increased salinity caused by surface coal mining. These protocols require subsampling procedures and identification of fixed numbers of individuals regardless of organism density, limiting measures of community structure. Quantitative sampling involves enumeration of all individuals collected within a defined area and typically includes larger sample sizes relative to semi-quantitative sampling, allowing expanded characterization of the benthic community. Working in central Appalachia, I evaluated quantitative and semi-quantitative methods for bioassessments in headwater streams salinized by coal mining during two time periods. I compared the two sampling methods for capability to detect SC-induced changes in the macroinvertebrate community. Quantitative sampling consistently produced higher estimates of taxonomic richness than corresponding semi-quantitative samples, and differences between sampling methods were found for community composition, functional feeding group, dominance, tolerance, and habit metrics. Quantitative methods were generally stronger predictors of benthic community-metric responses to SC and were more sensitive for detecting SC-induced changes in the macroinvertebrate community. Quantitative methods are advantageous compared to semi-quantitative sampling methods when characterizing benthic macroinvertebrate community structure because they provide more complete estimates of taxonomic richness and diversity and produce metrics that are stronger predictors of community response to elevated SC.<br>Master of Science<br>Surface coal mining in central Appalachia, eastern USA, contributes to increased salinity of surface waters, causing adverse effects on water quality and aquatic life. Stream condition is often evaluated through sampling of benthic macroinvertebrates because they are ubiquitous in aquatic environments and differ in sensitivity to various types of pollution and environmental stressors. In central Appalachia, studies have largely relied on semi-quantitative sampling methods to characterize effects of elevated salinity on benthic macroinvertebrate communities in headwater streams. These methods are ‘semiquantitative’ because processing of samples requires subsampling procedures and identification of a fixed number of individuals, regardless of the number of organisms that were originally collected. In contrast, quantitative sampling involves identification and counting of all collected individuals, often resulting in organism counts that are much higher than those of semi-quantitative samples. Quantitative samples are typically more time-consuming and expensive to process but allow for expanded description of the benthic macroinvertebrate community and characterization of community-wide response to an environmental stressor such as elevated salinity. Working in central Appalachian streams, I compared 1) depictions of benthic macroinvertebrate community structure; 2) benthic community response to elevated salinity; and 3) the minimum levels of salinity associated with community change between quantitative and semi-quantitative methods. Quantitative sampling methods provide many advantages over semi-quantitative methods by providing more complete enumerations of the taxa present, thus enhancing the ability to evaluate aquatic-life condition and to characterize overall benthic macroinvertebrate community response to elevated salinity caused by surface coal mining.
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GOMES, RAPHAEL F. "Avaliação de compostos orgânicos semi-voláteis em amostras de águas subterrâneas via CG/EM utilizando microextração líquido-líquido dispersivo - DLLME." reponame:Repositório Institucional do IPEN, 2014. http://repositorio.ipen.br:8080/xmlui/handle/123456789/23176.
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Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2014-12-19T17:05:43Z
No. of bitstreams: 0<br>Made available in DSpace on 2014-12-19T17:05:43Z (GMT). No. of bitstreams: 0<br>Dissertação (Mestrado em Tecnologia Nuclear)<br>IPEN/D<br>Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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Johansson, Frida, and Nina Larsen-Spasojevic. "Verktyg för effektiviserad provtagning på råvatten : Ett arbete utfört i samarbete med Laholmsbuktens VA & miljöförvaltningen i Halmstad." Thesis, Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-37255.
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The task of providing clean drinking water is made more demanding since pollutants have the ability to percolate into the groundwater. Because of the limited budget for drinking water monitoring and the high cost of drinking water contaminant analysis, it is of the highest importance to only analyze relevant contaminants. The aim of this study is thus to develop a monitoring tool that is adapted according to the specific industrial activities and land uses in a water catchment area to simplify and target relevant pollutants in raw water. This will also minimize the costs and increase the effectiveness of the groundwater monitoring. First we conducted a scientific data literature search to empirically enquire the answers to the following questions: (1) Can a so called basic analytical parameter package be designed with appurtenant addition packages? (2) What environmentally hazardous industries are present in the water catchment area of the water source Harplinge-Dettan? (3) How can it be assured that a parameter package is complete, and that not new or forbidden substances are being used and which are not being identified? We further mapped out the surrounding industries in the area of Harplinge-Dettan as well as the agricultural purposes of the land. From here we designed a basic analytical parameter package, which essentially is a list of possible parameters that can be found in a water catchment area. These parameters are recurrent pollutants that can be found in any catchment area. Additionally, we designed several additional packages which are specific to the surrounding industries for that water catchment area. Subsequently, the parameters here are outliers found in the basic analytical parameter package. This means that these are non-recurring pollutants that can only be linked to a specific source (i.e. trikloretylen can be linked to dry cleaning facilities, but no other activity in the area).
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Pearce, Austin Willis. "Assessing Phosphorus Sources with Synoptic Sampling in the Surface Waters of a Mixed-Use, Montane Watershed." BYU ScholarsArchive, 2017. https://scholarsarchive.byu.edu/etd/6374.
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Few elements in surface waters are monitored as closely as phosphorus (P) due to its role in the eutrophication and degradation of surface waters. Limiting P mobilization from source areas is, therefore, a central goal of water quality protection plans. But the work of locating sources in mixed-use watersheds is challenged by the spatial and temporal variability of critical source areas (CSAs) of P. Synoptic sampling is a proven method for capturing the spatial variation of water quality parameters in surface waters, though it's not often used to track temporal dynamics across the same study area. Phosphorus fractionation is an analytical method that divides the total P (TP) in water into fractions, which for this study included total dissolved P (TDP), particulate P (PP), dissolved reactive P (DRP), and dissolved organic P (DOP). The objective of this study was to demonstrate the utility of combining temporally repeated synoptic sampling with simple P fractionation as a unique strategy for locating and characterizing CSAs of P. Seven synoptic sampling campaigns were conducted over a two-year period (March 2015 – July 2016) in a rural, montane watershed in north central Utah, USA. In each campaign, we sampled 18 sites across three tributaries (Main Creek, Spring Creek, and Little Hobble Creek) during three distinct, annual hydrologic periods (rising flow, peak flow, and baseflow). Temporal repetition clearly identified the rising flow period as the period with greatest P loading in the watershed. Combining repeated synoptic sampling and P fractionation successfully identified CSAs of P and most probable transfer pathways. Specifically, stream segments along lower Spring Creek and Main Creek were associated with the greatest increases of PP loads during periods of rising flow and peak flow. In the same time periods, the greatest DOP loads stemmed from forested areas as well as areas in the lower watershed associated with winter grazing of cattle. The watershed exhibited a significant background concentration of DRP from groundwater-driven subsurface sources in the lower half of the watershed that persisted year-round. These assessments can be used to develop management practices that limit various P loads from these respective critical source areas. The characterization of CSAs could not have been made using only a traditional synoptic sampling approach. This study demonstrated that the combination of repeated synoptic sampling and P fractionation can be an effective technique for locating and characterizing critical P source areas in order to guide best management practices that improve surface water quality.
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McCurdy, Porcha. "Storm Sampling to Assess Inclement Weather Impacts on Water Quality in a Karst Watershed: Sinking Creek, Watauga Watershed, East Tennessee." Digital Commons @ East Tennessee State University, 2020. https://dc.etsu.edu/etd/3724.
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Escherichia coli changes in Sinking Creek, an impaired water body in the Watauga watershed of northeast Tennessee, were assessed during storm events using water samples collected with ISCO automated samplers during eight storms at two locations. Turbidity and electrical conductivity (EC) data loggers were deployed in the creek, and dissolved oxygen (DO) was measured in situ to test the stream’s water quality and reaction to inclement weather. Cotton fabric was deployed at both locations and sent to an external lab to test for the presence of Optical Brighteners (OB), which are indicators of residential wastewater. E. coli and turbidity at the creek generally increased within 2.5 hours of a rain event, remaining above the single sample standard for several hours during the storm. At the spring, E. coli became elevated within 30 minutes of precipitation onset, but generally decreased below the standard during the event.
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Fitzgerald, Nicholas B. "The Small Volume Autonomous Water Sampler (SVAWS): An Innovative, Cost- Effective, Adaptable Protocol." PDXScholar, 2014. https://pdxscholar.library.pdx.edu/open_access_etds/1533.
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As of 2007, U.S. pesticide use stood at 1.1 billion pounds with 80% of all usage in agriculture. Such realities pose a potentially dangerous threat to our surface water bodies. This research provides a detailed analysis of the design, operation and field testing of a prototype water sampler, the Small Volume Autonomous Water Sampler (SVAWS). The research includes a discussion of the design and construction of the SVAWS. Seven USGS employees operated the SVAWS in a number of different states and conditions in order to collect samples for pesticide analysis. Field-testing outcomes of the SVAWS were measured through a Participant Survey Request and a Likert-Scale Assessment.
Overall, survey data proved the SVAWS to be an effective device for collecting water samples in different locations and conditions. Users also understood the SVAWS has significant potential for applications other than pesticide studies. While feedback did show a number of alterations or modifications could improve the design, the device proved to be effective across many of its goals, from valid water sampling to reducing costs of sample acquisition. Recommendations for future research include these and other avenues of research. A conclusion addresses the potential future of the SVAWS with respect to water sampling applications.
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Del, Valle Lemuel Alejandro. "Water Quality Internship with the Ohio Environmental Protection Agency." Miami University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=miami1470088630.
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Chastain, James R. Jr. "A Heuristic Methodology for Locating Monitoring Stations to Detect Contamination Events in Potable Water Distribution Systems." Scholar Commons, 2004. https://scholarcommons.usf.edu/etd/988.
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The requirements to protect public water systems from intentional contamination have expanded in the years following September 11, 2001. The areal extent and non-linear nature of water demand and movement in the distribution system makes efficient location of sampling points difficult. This difficulty is compounded by the fact that contamination conceptually can occur at any point and at any time within the distribution system. Small to mid-sized water systems are especially at a disadvantage in addressing this issue due to limited resources available to them.
This paper proposes a heuristic methodology to identify strategic locations within the system that can be established as critical detection points for such occurrences. The process uses off-the-shelf software and is structured to be accessible to small and mid-sized water system managers. This methodology is different from others proposed in the literature in that it uses computer simulations to create a database of water system response to contamination at every node in the system. A process is developed to mine this database systematically after considering concentration thresholds and "time since injection" parameters. Finally, using pivot tables and graphs, a network of monitoring locations is identified to provide efficient coverage of the system under the conditions imposed.
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Harvey, Jonathan Paul. "The evaluation and development of electric fishing gears and sampling strategies for the assessment of fish stocks in large water bodies." Thesis, University of Hull, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361492.
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Marinaro, Ralph Michael. "Investigation of water vapor effects on the detection of nitric acid vapor with the tungstic acid technique." Diss., Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/71262.
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An automated tungstic acid technique (TAT) has been successfully used to measure gaseous HNO₃ in the presence of water vapor. The TAT is based on the diffusion of gaseous HNO₃ to the interior walls of a tube coated with tungsten VI oxide (WO₃), where it is selectively chemisorbed. The collected HNO₃ sample is thermally desorbed from the WO₃ surface, as NO, and measured by a chemiluminescent oxides of nitrogen analyzer. The integrated analyzer response is directly proportional to the nitric acid collected.
Based on nitric acid hydration characteristics, a decrease in the diffusion coefficient and thus collection efficiency for denuder type measurement techniques may result with increased atmospheric water vapor (i.e., relative humidity). This study emphasizes the effect of water vapor (i.e., relative humidity) as a potential interferent for HNO₃ collection with the TAT system.
The effect of water vapor (< 78% RH) on the collection efficiency for HNO₃ with the tungstic acid technique is negligible at 25°C, but is significant only at elevated sampling temperatures. This threshold effect is further substantiated and eliminated when a modified sampling collection system was designed with coolant capabilities. The new design has been tested to sub-part-per-billion (NO<sub>x</sub> analyzer detection limit) levels with minimal loss of gaseous HNO₃ signal, thereby increasing sensitivity to atmospheric HNO₃ concentrations and maintaining the gas/aerosol sample integrity.<br>Ph. D.
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Anderson, Malin. "Dynamics of phosphorus transport and retention in a wetland receiving drainage water from agricultural clay soils." Thesis, Linköpings universitet, Ekologi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-68773.
Full textAbstract:
A constructed wetland (0.08 ha) receiving drainage water from a small agricultural catchment (22 ha) with clay soil, was investigated with respect to phosphorus dynamics and retention. The aim was to evaluate the function of the wetland with respect to phosphorus retention, and relate that to gross sedimentation as measured with sediment traps. Hydraulic load and phosphorus retention were estimated for 2003-2010 based on monitoring data. Furthermore, water quality dynamics was studied during three intensive sampling periods of 3-5 days during 2010. For each period, phosphorus retention was calculated and the relationship between flow and phosphorus concentrations analysed. Additionally, the gross sedimentation rate was estimated using sediment traps, and the phosphorus, carbon and nitrogen content analysed. The results suggested that there was no net retention of phosphorus during 2003-2010, except for 04/05. During the intensive sampling periods, release of phosphorus from the wetland mainly occurred during high flow. Sediment analyses showed that settling of inflow particles mostly occurred in the inlet pond, while the sediment found in a shallow vegetated area and outlet pond likely originated from internal processes rather than from the catchment. In fact, the gross sedimentation of phosphorus during April-July and July-August, respectively, exceeded the measured phosphorus inflow. The results showed that short periods with rapid flow increases were crucial for the wetlands function and thus high frequency sampling must be done during these periods. Furthermore, it seems that the particles lost from the catchment during high flows are too small to settle in the wetland.
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Girleviciute, Aiste. "Uppföljning av reningsfunktionen i Steningedalens våtmark." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-353512.
Full textAbstract:
Dagvattnet från Märsta är belastat med bland annat tungmetaller och näringsämnen. Vattnet hamnar i Märstaån och transporteras vidare ut till Mälaren. Steningedalens våtmark är ett dammsystem som renar och fördröjer en del av Märstaåns flöde före transport ut mot Mälaren. Syftet med detta självständiga arbete på kandidatnivå har varit att undersöka anläggningens reningsfunktion med hjälp av sedimentprovtagning. Sedimentprover har tagits vid in- och utloppet och en kemisk analys av dessa har utförts i ett ackrediterat laboratorium. Resultaten från in- och utloppet har jämförts för att se om det sker en minskning av föroreningar genom systemet. Fem sedimentfällor har placerats ut i delar av dammsystemet för att undersöka sedimentfördelningen och muddringsbehovet i anläggningen. Resultatet av studien visade att dammsystemet har en god vattenreningsfunktion med avseende på tungmetallerna bly, nickel, kadmium, krom, koppar och zink samt näringsämnet fosfor. Anläggningen har bedömts att vara i behov av muddring.<br>In Märsta, the storm water is contaminated with heavy metals and nutrients (nitrogen and phosphorus) among other pollutants. The water emits to the river Märstaån and further to the lake Mälaren. The wetland of Steningedalen is a pond system that delays part of the stream in Märstaån and purifies the water on its way through the system. This independent project is based on investigation of the purification functioning at Steningedalen wetland. The investigation has been done by sediment sampling and analysis. The samples were taken from the inlet and the outlet of the pond system. Chemical analysis has been made on these samples in an accredited laboratory. The results were compared in order to see if there is a trend through the system. Five sediment traps were placed in parts of the system to study the distribution of the sediment and the need of dredging. The results of the study have concluded that the stormwater pond system has a good water purification function with regard to heavy metals lead, nickel, cadmium, chromium, copper and and zinc aswell as the nutrient phosphorous. The study has also shown that the system is in need of dredging.
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Clark, Brandi Nicole. "Effect of Installation Practices on Galvanic Corrosion in Service Lines, Low Flow Rate Sampling for Detecting Water-Lead Hazards, and Trace Metals on Drinking Water Pipeline Corrosion: Lessons in Unintended Consequences." Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/73180.
Full textAbstract:
Corrosion of drinking water distribution systems can cost water utilities and homeowners tens of billions of dollars each year in infrastructure damage, adversely impacting public health and causing water loss through leaks. Often, seemingly innocuous choices made by utilities, plumbers, and consumers can have a dramatic impacts on corrosion and pipeline longevity.
This work demonstrated that brass pipe connectors used in partial lead service line replacements (PLSLR) can significantly influence galvanic corrosion between lead and copper pipes. Galvanic crevice corrosion was implicated in a fourfold increase in lead compared to a traditional direct connection, which was previously assumed to be a worst-case connection method.
In field sampling conducted in two cities, a new sampling method designed to detect particulate lead risks demonstrated that the choice of flow rate has a substantial impact on lead-in-water hazards. On average, lead concentrations detected in water at high flow without stagnation were at least 3X-4X higher than in traditional regulatory samples with stagnation, demonstrating a new 'worst case' lead release scenario due to detachment of lead particulates.
Although galvanized steel was previously considered a minor lead source, it can contain up to 2% lead on the surface, and elevated lead-in-water samples from several cities were traced to galvanized pipe, including the home of a child with elevated blood lead.
Furthermore, if both galvanized and copper pipe are present, as occurs in large buildings, deposition corrosion is possible, leading to both increased lead exposure and pipe failures in as little as two years. Systematic laboratory studies of deposition corrosion identified key factors that increase or decrease its likelihood; soluble copper concentration and flow pattern were identified as controlling factors. Because of the high copper concentrations and continuous flow associated with mixed-metal hot water recirculating systems, these systems were identified as a worst-case scenario for galvanic corrosion.
Deposition corrosion was also confirmed as a contributing mechanism to increased lead release, if copper pipe is placed before a lead pipe as occurs in partial service line replacements. Dump-and-fill tests confirmed copper solubility as a key factor in deposition corrosion impacts, and a detailed analysis of lead pipes from both laboratory studies and field tests was consistent with pure metallic copper deposits on the pipe surface, especially near the galvanic junction with copper.
Finally, preliminary experiments were conducted to determine whether nanoparticles from novel water treatment techniques could have a negative impact on downstream drinking water pipeline infrastructure. Although increases in the corrosion of iron, copper, and stainless steel pipes in the presence of silver and carbon nanomaterials were generally small or non-existent, in one case the presence of silver nanoparticles increased iron release from stainless steel by more than 30X via a localized corrosion mechanism, with pitting rates as high as 1.2 mm/y, implying serious corrosion consequences are possible for stainless steel pipes if nanoparticles are present.<br>Ph. D.