Дисертації з теми "Ground Water contamination"
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1
Halstead, John Michael. "Managing ground water contamination from agricultural nitrates." Diss., Virginia Polytechnic Institute and State University, 1989. http://hdl.handle.net/10919/54787.
Повний текст джерелаАнотація:
Ground water contamination from agricultural nitrates poses potential adverse health effects to a large segment of the rural population of the United States. Contamination is especially prevalent in livestock intensive areas, which produce large quantities of animal waste with substantial nitrogen content.
In this study, potential management strategies for reducing nitrate contamination of ground water from agricultural sources were examined using an economic-physical model of a representative dairy farm in Rockingham County, Virginia. A mixed integer programming model with stochastic constraints on nitrate loading to ground water and silage production was used to simulate the impacts of various nitrate loading reduction strategies on estimated farm level net returns over variable costs. A survey of all dairy operations in the county was conducted to assist in specifying the mathematical programming model, identify current nutrient management and quality issues, and gauge farmers’ attitudes toward ground water quality and agricultural chemical use.
Results of the model indicate that substantial reductions in current nitrate loadings are possible with relatively minor impacts on farmers’ net returns through the use of currently practiced approaches of cost sharing for manure storage facility construction and nutrient management planning. Greater loading reductions are achievable through presently untried policies of land use restrictions, bans on purchase of commercial fertilizer, and imposition of standards on loadings to ground water. These reductions are achieved, however, at higher costs in terms of reduced net returns.
Study results indicate that a wide range of policy options exist for reducing nitrate loading to ground water; these reductions, while varying in cost, do not appear to come at the expense of eliminating the economic viability of the county dairy sector. Model results indicate that reductions in nitrate loading of 40 to 70 percent (on average) could be achieved with reductions in farmers’ net returns of one to 19 percent, respectively, when cost sharing for manure storage construction was provided. Explicit consideration was given to the annual variability in nitrate loading due to weather and other factors. The result was higher policy costs than when average loadings alone were considered.Ph. D.
2
Montague, David Joel. "Managing agricultural contamination of ground water: the institutional framework." Thesis, Virginia Tech, 1988. http://hdl.handle.net/10919/43408.
Повний текст джерела
3
Aubin, Eric. "Impact of water table management on ground water contamination by two herbicides." Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=55410.
Повний текст джерелаАнотація:
Two field investigations were undertaken to study the role of water table management in reducing herbicide pollution of ground water. One of the three-year studies (1992-1995) was conducted in a sandy field near Joliette (Laurin farm), (Quebec) to monitor the herbicide metribuzin where potatoes were grown. Two water table management systems were evaluated, namely subsurface drainage and subirrigation. Soil and ground water samples were taken at two week intervals, once before and six times after the herbicide application.The amount of rainfall received in the first few weeks following herbicide application is crucial in assessing the extent of ground water contamination. In 1992, fewer rainfall events occurred after the application as compared to 1993, so metribuzin leached slowly. In 1992, it appears that subirrigation reduced ground water contamination by a factor of 10 through enhanced degradation and the greater effect of dilution. However, the role of subirrigation in reducing the metribuzin contamination of ground water was negligible in 1993 due to considerable leaching soon after the application.
The second project was conducted in an organic soil in St-Patrice-de-Sherrington (Van Winden farm) where the herbicide prometryn was studied. Surface irrigation with a controlled water table was also used as a water table management system. One experimental unit was used for each of the three treatments (subirrigation, surface irrigation and subsurface drainage).
The herbicide application rate was greater at the Van Winden farm than in the Laurin farm (5.5 kg/ha versus 1.0 kg/ha). However, a higher adsorption coefficient of the organic soil minimized the leaching process. Ground water contamination was less extensive in the organic deposit. The effect of subirrigation in reducing ground water contamination was significant when the water table was shallow. Prometryn degradation was relatively slow during the summer. Moreover, significant amounts of prometryn carried-over into the soil after the winter season, so it appears to be a quite persistent herbicide in our climate.
4
Anderson, Jacob. "Geochemical Tracers of Surface Water and Ground Water Contamination from Road Salt." Thesis, Boston College, 2013. http://hdl.handle.net/2345/3313.
Повний текст джерелаАнотація:
Thesis advisor: Rudolph HonThe application of road de-icers has lead to increasing solute concentrations in surface and ground water across the northern US, Canada, and northern Europe. In a public water supply well field in southeastern Massachusetts, USA, chloride concentrations in ground water from an unconfined aquifer have steadily risen for the past twenty years. The objectives of this study are to understand spatial and temporal trends in road salt concentrations in order to identify contamination sources and fate. To this end, the methods of this project include field and lab work. Water samples were collected from surface, near-surface, and ground water from March 2012 to March 2013. The other major field data are specific conductance measurements from probes located in three piezometers. In the lab, all samples were analyzed for major ions with ion chromatography analysis. Additionally, trace elements were measured by inductively coupled plasma analysis on a subset of samples. The results of these hydrogeochemical procedures showed several important trends. First, the highest concentrations of sodium and chloride from near-surface samples were located near to roadways. Second, ground water samples taken from glacial sediments contained relatively high concentrations throughout the water column, whereas ground water samples from wetlands had high concentrations only near the surface. Third, there was no clear relationship between pH and cation concentrations. Finally, specific conductance data showed strong seasonal trends near to the surface, whereas values taken from deeper in the aquifer were steadily increasing. Based on these results, it is highly probable that road salt application is the dominate contamination source. The pathways of road salt in the watershed include runoff into surface water and infiltration into the vadose zone and ground water. Road salt appears to preferentially travel through glacial features rather than floodplain features. It is possible that sodium from road salt is sorbed to aquifer sediment and displaces other cations. However, the low values of trace metals suggest that cation exchange is not mobilizing heavy metals. Finally, the increasing specific conductance values deep in the aquifer suggest that road salt is retained within the aquifer and concentrations will likely increase in the future if the current road salt application procedures are continued
Thesis (MS) — Boston College, 2013
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Earth and Environmental Sciences
5
Hussein, Maged M. "Impact of ground-water contamination on the Great Miami River basin /." The Ohio State University, 1997. http://rave.ohiolink.edu/etdc/view?acc_num=osu148794815862844.
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6
Day, Stephen Wayne. "Ground water contamination from an abandoned landfill site in Delaware County, Indiana." Virtual Press, 1986. http://liblink.bsu.edu/uhtbin/catkey/474188.
Повний текст джерелаАнотація:
Groundwater contamination by landfill generated leachate is a problem that is increasingly addressed for proposed and existing landfill sites.This thesis examines groundwater contamination movement from the abandoned Delaware County Municipal landfill. The site is located in the crest of a highly permeable sand and gravel glacial esker which allows for rapid movement of ground water and any contaminants introduced into it.The landfill site was originally investigated in the late 1970's by Ed Lusch, a graduate student at the Ball State University Geology Department. That study showed some indications of ground water contamination movement to about 400 feet west of the site, in the direction of ground water flow. This indicated position of a contamination plume suggested that leachate, generated from the landfill site, had moved to that position since (or possibly before) the closing of the landfill in 1971.The present study, using a combination of surface resistivity methods, on-site test wells, and chemical analyses of ground water, attempted to determine the degree of contamination movement from the site since the original study and the extent to which the local aquifer had been affected. Results of this investigation revealed an apparent slow movement of leachate from the landfill westward towards the Mississinewa River, also in the direction of ground water flow. Surface resistivity methods of this study revealed the plume of contamination (indicated by resistivity "low" area) to now exist at approximately the same location as indicated in the earlier study, but to have expanded laterally. This investigation also found indications of the contamination plume well into the underlying fractured dolostone.Chemical analyses of nearby residential wells also revealed slightly elevated amounts of chloride, ammonia and specific conductivity in the ground water of the glacial esker south of the abandoned landfill site. The presence of three other dump sites, including a sludge dump, along the esker south of the landfill, offers questions as to the source of ground water contamination.Ball State UniversityMuncie, IN 47306
7
Elmore, Andrew Curtis. "Monte Carlo simulation of ground water remediation at a Nebraska contamination site." Diss., The University of Arizona, 1991. http://hdl.handle.net/10150/185706.
Повний текст джерелаАнотація:
Characterization of the effectiveness of ground water contamination remediation alternatives is complex due to uncertainties associated with the ground water system. This dissertation presents a Monte Carlo simulation model for stochastic characterization of the maximum concentration of contaminant remaining in an aquifer after the application of pump and treat remedial alternatives. The model is written in FORTRAN 77 for the Convex 240. The model uses a publicly available finite difference code for flow analysis and a commercially available method of characteristics transport code. Hydraulic conductivity fields are randomly generated using the turning bands method; initial concentration fields are conditionally simulated on measured and estimated concentration values; and retardation coefficient fields are negatively correlated to hydraulic conductivity using partition coefficients sampled from a log normal distribution. The model was applied to three pump and treat alternatives selected for consideration at a Nebraska contamination site. Two dimensional analysis of flow and transport was performed. Special treatment of flow boundary conditions was necessary due to site conditions and model restrictions. The probabilistic analyses of the resulting maximum concentration ensembles were used to demonstrate decision analysis at the site. Beta probability distributions were fitted to the maximum output ensembles. The decision tree model incorporated monetary values, human health considerations, and regulatory issues as well as probabilistic considerations. Illustration of the decision analysis procedure showed that the choice of the optimal remedial alternative was dependent on the monetary value assigned to noncarcinogenic and carcinogenic adverse human health risks.
8
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.
Повний текст джерелаАнотація:
4 pp.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).
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.
9
Beck, Daniel S. "A ground water report on the Fernald, Ohio contamination in the Miami Valley Aquifer." Connect to resource, 1996. http://hdl.handle.net/1811/31770.
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10
Waters, Lois Diane. "Relationships Between Hybrid Poplar Tree Extractives and Ground Water Contamination at a Phytoremediation Site." Thesis, Virginia Tech, 2003. http://hdl.handle.net/10919/31583.
Повний текст джерелаАнотація:
In 1997, a phytoremediation program began at a creosote-contaminated former railroad tie yard in Oneida, Tennessee with the planting of over 1000 hybrid poplar trees onsite. Creosote, a mixture of hazardous chemicals composed of 85% polycyclic aromatic hydrocarbons (PAH) had entered the site soil and ground water. After planting, a seasonal ground water testing program began that monitored the progress of remediation by measuring the concentration of the 10 predominant PAHs in the contaminant plume: naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, chrysene, and benzo(b)fluoranthene. The concentrations of these compounds steadily decreased over time, but the role the trees played in the remediation was unclear.
In order to gain a clearer understanding of the role the trees played in contaminant remediation, chemical analysis of tree tissue began. It was not known whether the trees were taking up PAH contaminants or their metabolites or if the rhizosphere zone created by the trees simply enhanced the ability of the site microflora to degrade the PAH. The objectives of this research were to (1) develop a suitable method for the chemical analysis of tree tissue collected from a field site, (2) determine if there were any chemicals not usually found in poplar trees that occurred in the trees growing over contamination, (3) determine if bud, bark, and twig tissue differed in their ability to predict ground water contamination, and (4) determine if a spatial correlation existed between the aromatic compounds in the tree tissue and the ground water total PAH plume.
Two types of tree tissue/ground water comparisons were performed: spatial distribution of isoeugenol concentration in tree tissue with spatial distribution of total PAH in ground water over the area of interest; and the spatial distribution of the quantity of aromatic compounds in tree tissue with the spatial distribution of total PAH concentration in ground water. Due to unit discrepancies between the quantities of interest, all comparisons were made on a percentile basis.
Initial tree sampling revealed that several compounds not usually present in poplar trees occurred only in those trees growing over contamination. In the first part of this study, the concentration of one of these chemicals, the substituted phenol isoeugenol, was compared with the concentration of total PAH in ground water from samples collected from February-March 2002. The bark tissue percentiles fell within 20 percentiles of ground water total PAH concentrations in 60% of the study area. The twig tissue showed slightly better agreement, with 67% of the study area differing from ground water by twenty percentiles or less.
The second comparison took place over three sampling events: March 2001, July 2001, and February-March 2002. The number of unique aromatic compounds in bark, bud, and twig tissue was compared with the total PAH concentration in ground water. Twig tissue aromatic compound content was the most accurate predictor of ground water contamination among the tissue types. After excluding those chemicals likely to be interferences from consideration, twig tissue aromatic content agreed with ground water total PAH concentration to within 20 percentiles over 2/3 or more of the study area during each sampling event, suggesting the potential uptake of PAHs or their microbial metabolites as a mechanism of phytoremediation at the site.
Master of Science
11
Leiter, Maria Louise. "Extent and Sources of Nitrate Contamination of Drinking Water in an Agricultural Watershed in Southwest Ohio." Miami University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=miami1250265194.
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12
Selig, Margot Littman 1961. "The economics of nitrogen fertilizer cutbacks to reduce potential ground water contamination : a case study of selected Arizona crops." Thesis, The University of Arizona, 1992. http://hdl.handle.net/10150/192071.
Повний текст джерелаАнотація:
Agricultural uses of nitrogen have contributed to the degradation of around water quality nationwide. Although the seriousness of nitrate contamination of Arizona around water has yet to be determined, nitrogen rates in Arizona agriculture are among the highest in the country. This study used experimental crop data for 11 Arizona crops to examine the relationships between nitrogen fertilizer use and short-run net returns and yield. The results showed that 1) farmers may apply nitrogen 20 to 30 percent above the profit maximizing level with little effect on profits; 2) a nitrogen tax will be ineffective in reducing nitrogen use; and 3) farmers could often reduce nitrogen applications 10 to 20 percent below the yield maximizing level with minor losses in net returns.
13
Reilly, Darren A. "Identification of Local Ground Water Pollution in Northeastern Pennsylvania: Marcellus Flow-back or Not?" Kent State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=kent1397949957.
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14
John, David E. "Transport and Survival of Water Quality Indicator Microorganisms in the Ground Water Environment of Florida: Implications for Aquifer Storage and Waste Disposal." [Tampa, Fla.] : University of South Florida, 2003. http://purl.fcla.edu/fcla/etd/SFE0000155.
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15
Cecil, L. DeWayne. "Origin of chlorine-36 in the eastern Snake River Plain aquifer, Idaho, implications for describing ground water contamination near a nuclear facility." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ60526.pdf.
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16
James, Matt. "Detailed characterisation of ground water nitrate/leachate flow in gravelly deposits using EM and GPR methods with particular reference to temporal flow changes." Thesis, University of Canterbury. Geological Science, 2015. http://hdl.handle.net/10092/10270.
Повний текст джерелаАнотація:
Irthing Road is situated 20 kilometres north of the small town of Lumsden in Northern
Southland, New Zealand. Irthing Road is accessed from State Highway 97 and leads
north-west for 7 kilometres up the Irthing Creek Valley. The research site is situated 4.4
kilometres from the Irthing Road - State Highway 97 intersection and the area is at 300
metres elevation above sea level on gently south sloping Quaternary alluvial deposits.
The study was initiated by Environment Southland and Southern Geophysical Ltd with
the intention of investigating the potential uses of near surface geophysics in the mapping
of shallow groundwater contamination, specifically agriculturally sourced nitrates and
leachates. The changes in land use and the introduction of high density grazing of dairy
cattle on free draining soils in Southland has created cause for concern around the ease
at which large volumes of contaminants could potentially gain access to the shallow
groundwater system.
The investigation of the Irthing Road field site included: (1) background research into
historical land use changes that may have affected the area 2) a study of the Lumsden
area geological and hydrogeological setting 3) six trips to the field site throughout the
year to collect near surface geophysical data using a Geonics Ltd EM31-MK2, Dualem
Inc. DUAL-EM 421s, and Sensors & Software pulseEKKO Pro GPR system; 4) ground-
water testing conducted by Environment Southland; 5) an evaluation of the geophysical
and groundwater data sets to identify whether leachate concentrations were high enough
to register an anomalous response 6) the identification of how the groundwater system
at the Irthing Road field site behaves 7) a conclusion as to the effectiveness of all three
near surface geophysical techniques in this application.
The major conclusions that emerged from this study are: (1) the groundwater system
is transporting a large volume of water beneath the site and this leads to such effi-
cient removal of contaminants that the concentrations are not high enough to register a
response in the geophysical data 2) the groundwater system is highly sensitive to rain-
fall and this is a contributing factor to the variation within the geophysical data 3) the
Geonics Ltd EM31-MK2 and Sensors & Software pulseEKKO Pro GPR system returned
highly consistent results and have great potential in further contaminated groundwater
applications 4) Environment Southlands' DUAL-EM 421s needs more consistency, how-
ever the device has a lot of potential once reliability can be ensured 5) further research is
needed to determine the contamination
ow paths and destinations at a larger, regional
scale.
17
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.
Повний текст джерелаАнотація:
Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2014-12-19T17:05:43Z
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Dissertação (Mestrado em Tecnologia Nuclear)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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Naber, Steven John. "Nonlinear least-squares and universal-kriging estimation of source and ground-water parameters for several types of plumes caused by instantaneous contamination releases /." The Ohio State University, 1993. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487848531362977.
Повний текст джерела
19
John, David E. (David Eric). "Transport and survival of water quality indicator microorganisms in the ground water environment of Florida [electronic resource] : implications for aquifer storage and waste disposal / by David E. John." University of South Florida, 2003. http://purl.fcla.edu/fcla/etd/SFE0000155.
Повний текст джерелаАнотація:
Title from PDF of title page.Document formatted into pages; contains 322 pages.
Thesis (Ph.D.)--University of South Florida, 2003.
Includes bibliographical references.
Text (Electronic thesis) in PDF format.
ABSTRACT: Ground water resources are heavily used for drinking water supply and often as a receptacle for waste water. One concern is the possible contamination of wetland areas by ground water receiving septic system infiltration. To investigate this, two tracer studies were performed using the bacteriophage PRD-1 by seeding septic systems adjacent to wetlands with the phage and monitoring migration towards wetland areas. Transport velocities were evaluated based on appearance of tracer in sampling wells at various distances from the injection point. Velocities were estimated to be 0.25 m/d and 0.4 m/d at the two sites. Some retardation with respect to the conservative tracer SF6 was observed, with a factor of about 1.5. Due to dry conditions, the water table was well below surface, so transport of the virus into surface water was not observed. Survival of public-health-related microorganisms in ground water is also a concern.
ABSTRACT: The effects of temperature and total dissolved solids (TDS) on survival of 5 groups of indicator organisms were evaluated in controlled experiments. TDS did not have significant effects on inactivation of these microbes up to 1000 mg/l, but there was indication of reduced inactivation of enterococci at TDS concentrations of 3000 mg/l. Increased temperature consistently resulted in more rapid inactivation. Survival in aquifer and reservoir water samples was also evaluated, and significant effects due to water type, temperature, and pasteurization treatment were observed. Inactivation was more rapid in surface water sources, and pasteurization enhanced survival. For enterococci and DNA coliphage, pasteurization effects were more pronounced in surface water. DNA coliphage and perhaps fecal coliform appeared to be the more-conservative indicator organisms for aquifer injection monitoring.
ABSTRACT: Lastly, it was observed that inactivation rates were considerably slower in pore water of saturated limestone than in the bulk water column of similar water sources and conditions, particularly for enterococci and fecal coliform.
System requirements: World Wide Web browser and PDF reader.
Mode of access: World Wide Web.
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Li, Xuan. "In Situ Chemical Oxidation Schemes for the Remediation of Ground Water and Soils Contaminated by Chlorinated Solvents." Connect to this title online, 2002. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1023289254.
Повний текст джерелаАнотація:
Thesis (Ph. D.)--Ohio State University, 2002.Title from first page of PDF file. Document formatted into pages; contains xv, 179 p.; also contains graphics (some col.). Includes abstract and vita. Advisor: Franklin W. Schwartz, Dept. of Geosciences. Includes bibliographical references (p. 172-179).
21
MINDRISZ, ANA C. "Avaliação da contaminação da água subterrânea de poços tubulares, por combustíveis fósseis, no município de Santo André, São Paulo: uma contribuição à gestão ambiental." reponame:Repositório Institucional do IPEN, 2006. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11428.
Повний текст джерелаАнотація:
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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
22
Amraoui, Nadia. "Étude de l'infiltration dans les sols fins non saturés." Vandoeuvre-les-Nancy, INPL, 1996. http://www.theses.fr/1996INPL075N.
Повний текст джерелаАнотація:
Prédire la vitesse d'écoulement des eaux polluées provenant des déchets stockés dans les décharges est nécessaire pour évaluer les risques de contamination de la nappe phréatique. Par ailleurs, l'étude des risques d'inondation après une période pluviale nécessite la quantification des flux d'eau infiltrés dans les sols naturels. Ceci exige la connaissance des propriétés hydrodynamiques du sol à l'état partiellement saturé. Ce travail s'intéresse à l'infiltration dans les sols fins non saturés, intacts et compactés, au laboratoire et in situ. Un dispositif de mesure en régime transitoire de la conductivité hydraulique est mis au point et développé au laboratoire. Il permet d'utiliser la méthode des profils instantanés par des mini-tensiomètres. Les résultats ont montré que sur les échantillons compactés, l'augmentation de la teneur en eau initiale du sol n'influence pas de façon significative la relation entre sa conductivité hydraulique et sa succion. Toutefois, elle réduit la vitesse d'infiltration ainsi que l'avancement du front d'humidification. Par ailleurs, l'augmentation de la densité du sol réduit sa conductivité hydraulique pour des faibles valeurs de succion. Les chemins d'écoulement préférentiels, crées dans les éprouvettes compactées dynamiquement, ont été analysés à l'aide d'un traceur. Un système de traitement d'images a permis de quantifier les paramètres influençant ce type d'écoulement. Le perméamètre de Guelph a été utilisé dans des campagnes d'étude in situ et au laboratoire. Il a été modifié et adapté aux sols fins très peu perméables. Les valeurs de coefficient de conductivité hydraulique sont plus petites au laboratoire que in situ. En parallèle, les résultats obtenus expérimentalement ont été comparés à ceux prédits par différents modèles analytiques ; la courbe de rétention est très bien ajustée par le modèle de Fredlund et Xing, par contre la conductivité obtenue par ce modèle sous-estime les valeurs expérimentales
23
Battermann, Astrid. "Mathematical optimization methods for the remediation of ground water contaminations." [S.l.] : [s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=963762184.
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Spinola, Eduardo Costa. "Mercúrio na área de disposição final dos resíduos sólidos do munícipio de São Pedro da Aldeia – RJ." Niterói, 2017. https://app.uff.br/riuff/handle/1/4962.
Повний текст джерелаАнотація:
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Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro
Universidade Federal Fluminense. Instituto de Química. Programa de Pós-Graduação em Geoquímica, Niterói, RJ
A água é fator de produção e elemento fundamental para o desenvolvimento dos povos. Com a intensificação do seu uso, a água é encarada como um recurso finito. Isto é causado pelo crescimento da população. Como conseqüência da crescente oferta do lixo gerado por bens de consumo descartáveis e resíduos sólidos industriais diversos. São improvisadas áreas de destino aos resíduos sólidos sem uma infra-estrutura adequada. Essas áreas, freqüentemente acabam se tornando definitivas e gerando uma série de transtornos. Essas áreas, os “lixões”, são fontes do elemento mercúrio (Hg) que é considerado um poluente global com boa mobilidade, encontrado principalmente na água e alimentos aquáticos, capaz de causar disfunções no sistema nervoso deixando a população mundial em constante alerta. Esta poluição restringe o uso da água, devido a problemas ambientais e danos à saúde da população. No município de São Pedro da Aldeia, foram realizadas análises químicas, em água e sedimento em área de “lixão”, medindo a concentração de Hg e alguns outros metais (Fe, Mn e Zn), matéria orgânica, pH, condutividade e sulfeto, com o propósito de quantificar a concentração dos metais e estudar seu comportamento na região.
The water is a factor of production and fundamental element for the development of the peoples. With the intensification of its use, the water becomes faced as a finite resource. This is caused by the population growth. As a consequence of the increasing offer of disposable consumption products garbage and industrial solid residues are generated. Destination areas are improvised to the solid residues often without an appropriate infrastructure. Those areas frequently end if turning definitive and generating a series of upsets. Those areas, the landfills, are sources of the element mercury (Hg) that is considered a global pollutant with good mobility, found mainly in the water and aquatics foods, capable to cause dysfunctions in the nervous system leaving the world population in alert constant. This pollution restricts the use of the water, due to environmental problems and damages to the health of the population. In the municipal district of São Pedro da Aldeia, we realized chemical analyses, in water and sediment in a landfill area, measuring the concentration of Hg and some other metals (Fe, Mn and Zn), organic matter, pH, conductivity and sulfide, with the purpose of quantify the concentration of the metals and to study its behavior in the region.
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Álvares, Cyro Martins Bicudo. "Contribuição ao conhecimento do meio físico da região do lixão de São Carlos - SP, através de estudos geológicos, geofísicos, topográficos e químicos." Universidade de São Paulo, 2000. http://www.teses.usp.br/teses/disponiveis/18/18139/tde-16072018-161604/.
Повний текст джерелаАнотація:
O lixão da cidade de São Carlos foi colocado, aproximadamente por dezessete anos, em uma boçoroca formada em região sedimentar, sobre os arenitos da Formação Botucatu, sem nenhuma espécie de controle prévio, quanto a possibilidade de contaminação do meio físico e, especialmente da água subterrânea. Dada essa possibilidade de contaminação do aqüífero profundo, uma série de estudos são feitos no local, desde a década de 80. Este trabalho vem somar-se aos diversos outros na tentativa de aprofundar o conhecimento das condições em que se encontra o meio físico na região do lixão. Fazendo parte de um projeto maior este trabalho procurou, utilizando as ciências de geologia, geofísica, topografia e química, dar novos elementos e interpretações a esse conhecimento. Geologicamente, detectamos e avaliamos a presença de camadas penetrativas, hidraulicamente menos condutivas, como areias siltosas e, muito provavelmente, arenito silicificado ou diabásio em profundidade, o que poderia fazer que a contaminação não atingisse o aqüífero profundo. Para isso utilizamos o mapeamento geológico e a geofísica em três de suas técnicas: caminhamento elétrico, sondagens elétricas verticais e perfilagem de poços. Quimicamente, avaliamos a contaminação das águas subterrâneas em relação ao sentido do fluxo.For seventeen years, Sao Carlos\' solid wastes were placed in a gully formed in a sedimentary area, on the Botucatu Formation (friable sandstone and sands), without any form of control to prevent the contamination of the environment and, especially, of the ground water. Thanks to the possibility of contamination of the deep water source, a series of studies have been made in the area since the eighties. These studies were just another attempt, along with severaI others, to increase the knowledge of the environmental conditions surrounding the waste dump area. Being part of a greater project, different sciences were used such as geology, geophysics, topography and chemistry, in order to obtain new elements and a more acurate interpretation to the existing knowledge. Geologicaly, we detected a less hydraulicaly conductive silty sand layers and, probably, silicificated sandstone layers or diabase sill which could protect the deep water sources from being contaminated. Geologic mapping and geophysical techniques such as electric surveys and well logs were performed during the process. Chemically, we evaluated the ground water contamination in relation to the flow\'s direction.
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Kazour, Maria. "Active and passive biomonitoring tools for microplastics assessment in two highly polluted aquatic environments : case study of the Seine estuary and the Lebanese coast SOURCES OF MICROPLASTICS POLLUTION IN THE MARINE ENVIRONMENT: IMPORTANCE OF WASTEWATER TREATMENT PLANT AND COASTAL LANDFILL MICROPLASTICS POLLUTION ALONG THE LEBANESE COAST (EASTERN MEDITERRANEAN BASIN): OCCURRENCE IN SURFACE WATER, SEDIMENTS AND BIOTA SAMPLES JUVENILE FISH CAGING AS A TOOL FOR ASSESSING MICROPLASTICS CONTAMINATION IN ESTUARINE FISH NURSERY GROUNDS IS BLUE MUSSEL CAGING AN EFFICIENT METHOD FOR MONITORING ENVIRONMENTAL MICROPLASTICS POLLUTION?" Thesis, Littoral, 2019. http://www.theses.fr/2019DUNK0544.
Повний текст джерелаАнотація:
La production de plastique est en augmentation continue pour répondre à la forte demande mondiale. Cette production massive est la source d'importantes quantités de plastiques que l'on retrouve dans les milieux aquatiques. Parmi ces plastiques, les microplastiques (MP) (particules microscopiques d’une taille < 5 mm) se retrouvent dans l’eau, les sédiments et sont susceptibles d’être ingérés par divers organismes marins. Cette thèse se focalise sur (1) l’évaluation des sources et des apports de microplastiques au milieu aquatique et de leur présence dans les organismes, et (2) de tester la faisabilité d’utiliser des organismes vivants pour la surveillance de la pollution de l’environnement par les microplastiques. Deux zones côtières affectées par des pressions anthropogéniques ont été étudiées : Le Havre et le littoral libanais. Dans le premier cas, le rôle d’une station de traitement des eaux usées (STEP) et d’une décharge côtière dans l’introduction des microplastiques dans l’environnement a été étudié. Les MPs ont d’abord été analysés dans l'influent, la boue et l’effluent de la STEP. Leur devenir a été suivi selon un gradient de distance de la STEP au niveau de trois matrices : eau de surface, sédiments et moules sauvages (Mytilus spp.). Les MPs ont été trouvés au niveau de toutes les matrices avec une concentration qui diminue en s’éloignant de l’effluent. Des taux de microplastiques élevés (plus élevés que ceux trouvés à côté de la STEP) ont été observés à proximité de la décharge côtière, suggérant son rôle important comme voie d’entrée des MPs dans les eaux côtières. Le long de la côte libanaise, nous avons évalué pour la première fois la pollution par les MPs dans l'eau de mer, les sédiments et dans deux espèces marines importantes en terme de consommation humaine (un poisson pélagique: Engraulis encrasicolus et un bivalve: Spondylus spinosus). Les résultats ont montré différents patterns de concentration des MPs dans les matrices analysées. La présence de MPs dans les organismes était élevée (83.4% et 86.3% dans les anchois et les huîtres, respectivement). Ces résultats ont mis en évidence la pollution élevée liée aux MPs au niveau du bassin Levantin par rapport aux autres régions de la Méditerranée occidentale. De plus, les résultats obtenus indiquent une contribution potentielle des décharges côtières à cette pollution. Le plus souvent, les études sur les microplastiques impliquent l'échantillonnage d’organismes indigènes. Au cours de cette thèse, nous avons testé la faisabilité d'utiliser des organismes transplantés (encagement) pour évaluer la pollution par les microplastiques dans l'environnement marin côtier. Nous avons mis au point des expériences d'encagement avec des juvéniles de flets, Platichthys flesus, en estuaires et des moules bleues, Mytilus edulis, en zone côtière. Pour chaque espèce, l'abondance et les caractéristiques (forme, taille, couleur et type de polymères) des MPs ingérés par les individus encagés ont été comparées avec les MPs ingérés par des individus sauvages capturés sur le même site et avec ceux trouvés dans leur environnement (eaux de surface et sédiments). Nos résultats suggèrent que la technique d'encagement d'organismes peut constituer un outil prometteur pour la biosurveillance des MPs la rendant plus fiable et permettant une étude précise des effets biologiques des MPs sur une période d'exposition prédéterminéePlastic fabrication is increasing worldwide in response to daily human demands. This mass production is linked to the immense plastic marine litter found all around the world: each synthetic material is meant to find its way back into the aquatic systems. Anthropogenic pressure and the immense human population, the lack of appropriate plastic treatment process and the growing industrial activities advocate their presence in the aquatic environments. These plastics are then found in the form of microplastics (microscopic particle with a size < 5 mm) observed in the water, in the sediments and are prone to be ingested by various marine organisms along the trophic chain. This thesis focuses on (1) assessing microplastics sources and input into the aquatic environment and their occurrence in biota, and (2) to test the feasibility of using transplanted organisms (caging) for monitoring microplastics pollution in the marine coastal environment. Two coastal areas highly impacted by anthropogenic pressures were studied: Le Havre in France and the Lebanese coast. For the former, the role of a municipal wastewater treatment plant (WWTP) effluent and an abandoned coastal landfill as pathways for microplastics (MPs) input into the marine environment was assessed. MPs were first analyzed in raw sewage influent, sludge and effluent samples, and their fate was studied along a distance gradient from the WWTP in three matrices: surface water, sediments and wild mussels (Mytilus spp). MPs were found in all matrices with a decreasing abundance from the effluent. Strong MPs abundances (higher than those found near the WWTP effluent) were observed in the vicinity of the coastal landfill suggesting its importance as a MPs entry route into the marine coastal environment. Whereas for the Lebanese coast, we evaluated for the first time the MPs pollution in the seawater, sediments and two important seafood species (one pelagic fish: Engraulis encrasicolus and one bivalve: Spondylus spinosus). Results showed different patterns of MPs concentration in the analyzed matrices. The occurrence of MPs in the biota was high (83.4% and 86.3% in anchovies and spiny oysters, respectively). These results highlighted the high MPs pollution found in the Levantine Basin in comparison to other Western Mediterranean regions. In addition, the obtained results indicate the potential contribution of coastal landfills to this pollution. Most often microplastics studies involve collection of organisms’ samples from natural populations. In this thesis, we tested the feasibility of using transplanted organisms (caging) for monitoring microplastics’ pollution in the marine coastal environment. We developed caging experiments with juvenile European Flounder, Platichthys flesus, in estuarine nursery grounds and blue mussels, Mytilus edulis, in coastal marine environment. For each species, the abundance and characteristics (shape, size, color and type of polymers) of MPs ingested by caged individuals are compared with those ingested by wild individuals collected at the same site and with those found in their surrounding environment (surface water and sediments). Our results suggest that transplanted organisms (caging) may be a promising tool for MPs biomonitoring making monitoring more reliable with an accurate assessment of the biological effects of MPs over a predetermined exposure period
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Gao, Fuchun. "Waveform tomography and its application at a ground water contamination site." Thesis, 2004. http://hdl.handle.net/1911/18630.
Повний текст джерелаАнотація:
This thesis develops and applies seismic waveform tomography to solve the unique problem of imaging complicated shallow sub-structures with high resolution. Shallow sub-structures are commonly characterized by seismic reflection/refraction imaging, georadar and seismic travel time tomography (e.g., Steeples, 1998; Carcione et al., 2000 and Azaria, 2002). Their resolving power or applicability is often limited. In contrast, waveform tomography, a full wave field inversion technique, resolves sub-structures at a resolution that is a fraction of the illuminating wavelengths.
Forward modeling in waveform tomography is based on a finite difference solution to the acoustic wave equation in the space-frequency domain. During inversion for model parameters, the technique efficiently calculates the gradient of a misfit function with respect to model parameters by correlating back-propagated and forward modeled wave fields, avoiding the forbidding task of explicitly computing Frechet kernels. Part of this study compares travel time and waveform tomography in a synthetic cross-well test. The two tomographic approaches are found to be complementary if data contains no significant low frequency spectra.
I then apply waveform tomography to two datasets from a ground water contamination site at the Hill Air Force Base (HAFB) to sample formation heterogeneities and to map the 3D geometry of a buried paleo-channel where DNAPLs (Dense Non-Aqueous Phase Liquids) were dumped. The first is a VSP-surface seismic experiment. The final velocity model from waveform tomography applied to the VSP dataset generally correlates well with lithology logs, depth migrated 2D/3D reflection data and a velocity model from 3D travel time tomography. Large velocity variations vertically and laterally (200m/s) occur in a distance as short as ∼1m. The model is interpreted geologically and petrologically. Scale features down to ∼1.5m were recovered.
I then apply waveform tomography to 45 2D seismic profiles extracted from a 3-D surface seismic experiment at HAFB, and recover the 3D geometry of a buried paleo-channel acting as a trap for DNAPLs. By combining the identified cross-sectional geometry, the 3D geometry of the channel is reconstructed. The subsurface map could be used to plan injection/extraction well placements with good precision and low cost in the on-going ground water remediation program.
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Melo, Armindo Jorge Alves de. "Assessment of pesticide contamination in ground water and vegetables using environment friendly methodologies." Doctoral thesis, 2012. https://repositorio-aberto.up.pt/handle/10216/71928.
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Melo, Armindo Jorge Alves de. "Assessment of pesticide contamination in ground water and vegetables using environment friendly methodologies." Tese, 2012. https://repositorio-aberto.up.pt/handle/10216/71928.
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Evelyne, Rita J. "Evaluation of Btex Contamination in Bengaluru Groundwater and Remediation of Contaminated Water Samples." Thesis, 2020. https://etd.iisc.ac.in/handle/2005/4602.
Повний текст джерелаАнотація:
BTEX (benzene, toluene, ethylbenzene, and xylene isomers) are monoaromatic, volatile organic compounds (VOCs) with single benzene ring and various degree of alkylation. US EPA classifies benzene and TEX (toluene, ethylbenzene, and xylene) as Class A (Carcinogenic) and Class D pollutants, respectively. A major source of BTEX contamination in groundwater is leakage from storage tanks in gasoline filling stations and oil-refineries. Perusal of the groundwater quality data in problem areas of India shows availability of data for inorganic contaminants, microbial contaminants and pesticides but do not contain data on BTEX levels in groundwater.
Results of the study indicate that BTEX contamination of Bengaluru aquifers from leaky UST’s in petrol filling stations is not extensive as only 6 % of groundwater samples showed benzene presence in excess of the permissible limit, while TEX compounds were below permissible limit in all the 124 groundwater samples. BTEX levels in contaminated groundwater were sensitive to seasonal variations as higher BTEX concentrations were generally observed during post-monsoon than pre-monsoon season. Lower BTEX concentration during pre-monsoon is attributed to reduced leaching of organic compounds from the overlying soil overburden to aquifers.
A contaminant transport model using MODFLOW is created to obtain insight into the role of hydrodynamic dispersion and diffusion in the spread of BTEX plume in Bengaluru aquifer. Variations in Ss(specific storage) or Sy(specific yield) at given kx(aquifer permeability) did not affect the predicted BTEX concentrations in the observation well at any migration period. However, reduction in kx affected the BTEX concentration in the observation well. BTEX
migration modeled using the low kx (5E-7 m/s) generally agree well with the measured benzene, toluene, and total xylenes concentration values in the observation well.
Among various methods to treat BTEX contaminated water, adsorption has attracted considerable attention of researchers. Recycled materials such as tyre crumb rubber (TCR) have an advantage over other adsorbents, in terms of low cost and large availability. Permeable reactive barriers (PRB) are used for in-situ treatment of contaminated groundwater. The use of TCR particles as reactive media in PRB’s to treat BTEX contaminated groundwater is an attractive option, that has not been previously explored.
Results of the study showed that TCR particles are mainly composed by SBP (52.7%) and CB (24.5%) constituents. Despite a lesser presence (24.5%), the CB component of TCR accounts for bulk (83%) of toluene adsorption by the TCR-sand mix. Analysis of adsorption data using distribution coefficients (Kc), Scatchard plot and Freundlich isotherm implied that toluene molecules are adsorbed at energetically heterogeneous sites of the TCR particles. Adsorption in pores of different sizes was responsible for the heterogeneity of adsorption sites. Interactions between toluene molecules and the adsorption sites of TCR particles involve weak van der Waals attraction forces. Despite the weak bonding, bulk (91%) of the adsorbed toluene molecules is not released upon water leaching as the spatial arrangement of toluene molecules in the medium and fine pores of TCR particles hinders desorption. Adsorption isotherms identified 2.5% TCR + 97.5% sand mix as the optimum mix to treat toluene contaminated water. Batch experiment results predict that unit PRB column constructed with 2.5% TCR-97.5% sand mix can remediate 11013 KL of toluene contaminated (0.15 mg/L) groundwater near instantaneously.
Besides adsorption, biodegradation is extensively used to treat BTEX contaminated groundwater, wastewater, and subsurface soils. Microbial consortia isolated from activated sludge, gasoline contaminated soils, sea-tidal flat were successful in biodegradation of BTEX compounds. The feasibility of exploring bacterial cultures cultivated from gasoline contaminated soils and groundwater in Bengaluru city is an interesting bioremediation option.
Bioremediation is accomplished by enrichment of bacterial culture in minimal media with toluene as carbon source. Results of the study showed that Pseudomonas sp isolated from petroleum contaminated soil and Bacillus haynesii isolated from BTEX contaminated groundwater are capable of toluene biodegradation. At toluene concentrations of 5-300 mg/L, Pseudomonas could degrade 40 to 100% of the hydrocarbon concentration. Comparatively, Bacillus haynesii could degrade 22 to 66 % of available toluene concentration. Toluene degradation by the microbes followed first order kinetics with first order rate constant of 0.127 h-1. The lower toluene degradation ability of Bacillus haynesii is attributed to greater substrate inhibitory effect. Review of microbial facilitated toluene degradation studies indicate that Pseudomonas species have higher degradation efficiency than other bacteria strains.
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Selig, Margot Littman. "The economics of nitrogen fertilizer cutbacks to reduce potential ground water contamination : a case study of selected Arizona crops /." 1992. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_e9791_1992_520_sip1_w.pdf&type=application/pdf.
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Šrot, Martin. "Problematika farmak v podzemních vodách." Master's thesis, 2016. http://www.nusl.cz/ntk/nusl-352542.
Повний текст джерелаАнотація:
Main objective of the diploma thesis was to observe the concentrations of selected types of drugs in the environment around the area of the village Horní Beřkovice. This goal was achieved by monitoring of the drugs concentration in surface and ground waters at Horní Beřkovice site. Monitoring system allowed to detect the passage of pollution from the source of the contamination, through sewage treatment plant, the unsaturated zone and aquifer to a potential user of contaminated groundwater. The diploma thesis is based on the field data from TACR project. I have analyzed data from the six samplings at the area of the village Horní Beřkovice with regard to the observed drugs or their residues in surface and ground waters. I have compared the results with data from the sewage treatment plants in the river basin of Želivka. Keywords: ground water, surface water, sewage treatment plant, drugs, contamination
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Makgoka, Seretloane Japhtaline. "Comparison of water quality between sources and between selected villages in the Waterberg District of Limpopo Province; South Africa: with special reference to chemical and microbial quality." Thesis, 2005. http://hdl.handle.net/10386/91.
Повний текст джерелаАнотація:
Thesis (MPH)--University of Limpopo, 2005Water and sanitation inadequacy is still an environmental health challenge in several regions worldwide and a billion people lack access to safe water, while 2.4 billion people have inadequate sanitation [2]. Assessment of water quality by its chemistry includes measures of elements and molecules dissolved or suspended in water. Commonly measured chemical parameters include arsenic, cadmium, calcium, chloride, fluoride, total hardness, nitrate, and potassium [16]. Water quality can also be assessed by the presence of waterborne microorganisms from human and animals’ faecal wastes. These wastes contain a wide range of bacteria, viruses and protozoa that may be washed into drinking water supplies [21]. Three villages were selected for water quality analysis, based on their critical situation regarding access to water and sanitation: namely, Matlou, Sekuruwe and Taolome villages, situated in the Mogalakwena Local Municipality within the Waterberg district of the Limpopo Province, South Africa. A proposal was written to the Province of North Holland (PNH) and was approved for funding to start with the implementation of those projects, with 20% of each village’s budget allocated for water quality research [26]. This was a cross sectional, analytical study to investigate the chemical and microbial quality of water in Matlou, Sekuruwe and Taolome villages. The study was also conducted to explore methods used by household members to store and handle water in storage tanks. Water samples were collected and analysed according to the standard operating procedures (SOPs) of the Polokwane Municipality Wastewater Purification Plant in Ladanna, Polokwane City of South Africa. The questionnaire used was adopted from the one used for cholera outbreak in the Eastern Cape Province of South Africa. Results show that water from all sources in all the villages had increased total hardness concentration. Water from the borehole in Matlou village had increased number of total coliform bacteria. There were increased total and faecal coliform bacteria in storage tanks samples from Matlou village. Water samples from reservoirs in Sekuruwe and Taolome villages did not test positive for any microbial contamination. Water from xiv informally connected yard taps in Sekuruwe village had increased total coliform bacteria, while increased total and faecal coliforms were found in households’ storage tanks. Water samples from communal taps in Taolome village had minimal number of total coliform bacteria, while water from storage tanks had both increased total and faecal coliform bacteria. Matlou village was the only place with increased nitrate concentration at the households’ storage tanks. While all the villages had microbial contamination, Taolome village had the least number of coliform bacteria in water samples from households’ storage tanks as compared to Matlou and Sekuruwe villages. It is concluded that water from sources supplied by the municipalities are safe to be consumed by humans while water from informally connected taps and households’ storage tanks are not safe to be used without treatment. It is recommended that a health and hygiene education package be prepared for all the villages, so that handling of water from the main source into their storage tanks can be improved. Secondly, it is recommended that water in all sources be treated for total hardness and water in storage tanks in Matlou village be treated for nitrate. Thirdly, it is recommended that water be accessed everyday of the week, so that people do not use unsafe water supplies.
The Province of North Holland, Netherlands.
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"A preliminary ranking and evaluation method for determining the ground-water contamination potential of closed landfills [electronic resource] / by Catherine M. Böhlke." 1989. http://purl.fcla.edu/fcla/dl/SF00000084.jpg.
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"Relationship of karstification to ground-water quality [electronic resource] : a study of sinkholes as contamination pathways in Brandon Karst Terrain, Florida / by Jian Chen." 1993. http://purl.fcla.edu/fcla/dl/SF00000087.jpg.
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Vergunst, Thomas Maarten. "The potential for groundwater contamination arising from a lead/zinc mine tailings impoundment." 2006. http://hdl.handle.net/10413/3513.
Повний текст джерелаАнотація:
The mining industry produces vast quantities of overburden and mill tailings. In many instances the disposal of these wastes on the Earth's surface have caused local, and occasionally even regional, water resources to become contaminated. Contamination typically arises from the oxidation of metal sulfide minerals contained within these wastes. Upon oxidation these minerals release sulfate, their associated metal cations and acidity into solution. This study investigated the potential for groundwater contamination arising from a Pb/Zn tailings impoundment in the North West Province of South Africa (Pering Mine). The tailings is composed predominantly of dolomite, which imparts to the material an alkaline pH and a high acid buffering capacity. Acid-base accounting (ABA) established that the capacity of the tailings to buffer acidity surpasses any acid producing potential that could arise from pyrite (FeS2), galena (PbS) and sphalerite (ZnS) oxidation. These minerals account for about 3 to 6% of the tailings by mass. Total elemental analysis (XRF) showed that the material has high total concentrations of Fe (19083 mg kg-I), Zn (5481 mg kg-I), Pb (398 mg kg-I), S (15400 mg kg-I), Al (9152 mg kg-I) and Mn (29102 mg kg-I). Only a very small fraction of this, however, was soluble under saturated conditions. An estimation of potentially available concentrations, using the DTPA extraction method, indicated that high concentrations of Zn (1056 mg kg-I), and moderate concentrations of Pb (27.3 mg kg-I) and Cu (6.01 mg kg-I) could potentially be available to cause contamination. A number of leaching experiments were undertaken to accurately quantify the release of elements from the tailings material. These experiments were aimed at determining the potential for groundwater contamination and also provided a means whereby the long-term release of contaminants could be modelled using the convection-dispersion equation for solute transport. Four leaching treatments were investigated. Two consisted of using distilled water under intermittent and continuous flow, while a third used intermittent flow of deoxygenated distilled water to assess leaching under conditions of reduced oxygen. The.mobilisation of potential contaminants under a worst case scenario was assessed by means of leaching with an acetic acid solution at pH 2.88 (after the US Environmental Protection Agency's toxicity characteristic leaching procedure). The acid buffering potential of the tailings was considerable. Even after 8 months of weekly leaching with 1 pore volume of acetic acid solution the pH of the effluent was maintained above pH 5.90. The protracted acidity caused very high concentrations of Pb, Zn, Mu, Ca, Mg, Hg and S to be released into solution. Leaching the tailings with distilled water also caused the effluent to have noticeable traces of contamination, most importantly from S, Mg, Mu and Zn. In many instances concentrations significantly exceeded guideline values for South African drinking water. Modelling solute transport with the convectiondispersion equation predicted that sol- and Mu contamination could persist for a very long period of time. (±700 years under continuous saturated leaching), while Mg and Zn concentrations would most likely exceed recommended limits for a much shorter period of time (±300 years under the same conditions). In light of the various column leaching experiments it was concluded that seepage from the Pering tailings impoundment could cause groundwater contamination. A drill-rig and coring system were used to collect both tailings and pore-water samples from eight boreholes spread out across the tailings impoundment. These investigations showed that most of the impoundment was aerobic (Eh ranged from +323 to +454 mY) and alkaline (pH 8.0 to 9.5). This chemical environment favours sulfide oxidation and as a consequence high concentrations of S have been released into the pore-water of the impoundment (S concentrations ranged from 211 to 1221 mg r l ). The acidity released as a by-product of sulfide oxidation was being buffered by dolomite dissolution, which in turn was releasing high concentrations of Mg (175 to 917 mg r l ) and Ca (62.6 to 247 mg r l ) into solution. Metal concentrations in the pore-water were low as a result of the strong metal sorbing capacity of the tailings and possible secondary precipitation. The only metal which significantly exceeded recommended limits throughout the impoundment was Hg (concentrations were between 100 and 6000 times the recommended limit of 0.001 mg r l ). Under the current geochemical conditions it is expected that Hg, S and Mg will likely pose the greatest threat to groundwater. The main concerns associated with mine tailings are that of mine drainage and dust blow off..In order to eradicate the latter problem, the tailings impoundment at Pering Mine was covered with a layer of rocks. Modelling the water balance of the impoundment using the computer model HYDRUS-2D showed that the rock cladding has potentially increased the volume of drainage water seeping from the impoundment. In light of the leaching experiments and field work, which proved that water passing through the tailings became enriched with various potentially toxic elements, it is expected that the problem of groundwater contamination around Pering Mine has been further exacerbated by the rock cladding. It was therefore concluded that there would be a strong likelihood of groundwater contamination in the vicinity of the mine.Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.
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Battermann, Astrid [Verfasser]. "Mathematical optimization methods for the remediation of ground water contaminations / vorgelegt von Astrid Battermann." 2000. http://d-nb.info/963762184/34.
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Moritz, Anja Miriam. "Establishing baseline concentration and δ¹³C signature of methane in shallow ground waters of the St. Lawrence Lowlands, QC, Canada: A tool for determining shale gas contamination". Thesis, 2014. http://spectrum.library.concordia.ca/978420/1/Moritz_MSc_S2014.pdf.
Повний текст джерелаАнотація:
With the increased interest in non-conventional energy sources, major environmental questions are being raised concerning the possible impacts of shale gas exploitation on the quality of ground waters. The extraction of shale gas is done by hydraulic fracturing, which utilizes large volumes of water and fracturing fluids to break the source rocks that entrap gases such as methane, ethane and propane. Because it is uncertain whether these fracturing fluids and gases can contaminate shallow ground waters, it is important to assess the baseline concentration of these gases before hydraulic fracturing activities are initiated to be able to determine the source of future ground water contaminations. In this work, we measured the natural concentrations and sources of hydrocarbons dissolved in ground waters of the St. Lawrence Lowlands, QC, Canada, in 130 ground water samples collected from private (n=81), municipal (n=34) and observation (n=15) wells. Localized pools of high concentrations of methane of mostly bacterial origin (biogenic) were found throughout the study area. Three samples showed high concentrations of methane bearing a δ¹³C signature specific to deep sources (thermogenic) but a gas wetness ratio (C1/(C2+C3)) falling outside the thermogenic gas window. This result suggests mixing with gas from other sources, migration through the bedrock, or partial oxidation of the gas. The results obtained in this study will be used as a reference for future research projects and monitoring activities on the impact of shale gas exploration and exploitation on ground water quality.
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Edwards, Jamie Joyce. "Building the capacity for watershed governance." Thesis, 2020. http://hdl.handle.net/1828/11727.
Повний текст джерелаАнотація:
BC Hydro’s Water Use Planning (WUP) process is one of the world’s most comprehensive hydroelectric dam operational reviews and has served as a model to revise hydropower operating plans with the participation of an inclusive range of stakeholders, rights holders, and the use of up-to-date scientific information, that meets social and environmental goals alongside economic targets. In 2000, BC Hydro initiated a WUP process in the Jordan River watershed. This watershed hosts a wide diversity of water users, including active resource industry stakeholders (mining, forestry, and hydropower), Indigenous rights holders, and rural community citizens; which is representative of watersheds in British Columbia with established WUPs. BC Hydro finalized the Jordan River WUP in 2003, which focuses on establishing critical freshwater flows for fish habitat and achieving specific recreational values of the local community. However, numerous other issues still remain that were beyond the scope of the WUP process, including water quality concerns that were continually brought up by citizens during the consultative process of the WUP. In addition to these concerns, biological monitoring following the implementation of the WUP suggests that contamination from an inactive copper mine has affected and altered sensitive water quality parameters for a healthy Pacific salmon habitat in Jordan River. Yet, there has not been an extensive water quality study conducted that examines the spatial or seasonal water quality extents of the mining contamination in Jordan River, specifically copper. Consequently, fourteen years after the creation of the WUP, local advocates are still struggling to have their concerns heard by the entity responsible for freshwater flow, BC Hydro, alongside federal and provincial government agencies. Advocates are calling for the creation of a watershed-based group as a mechanism for having greater influence in water planning and governance processes. This study explores the research question: if and how has the WUP process contributed to creating watershed governance capacity? This social science thesis project employs a mixed-methods approach using both quantitative and qualitative data. The study includes a document review of relevant water governance literature and focuses on examining the freshwater quality of the Jordan River. Water quality samples were collected over a five-week period from five sites on the Jordan River beginning in September and concluding in October of 2015 during the most sensitive periods of salmon spawning activity in the lower reaches of the Jordan River. Spatial and seasonal water quality trends were identified, and analysis concluded that copper is the primary contaminate affecting the productivity of a healthy salmon habitat in the Jordan River. Acid mine drainage (AMD) processes were identified throughout the water quality data and are strongly influenced by the proximity of existing mine waste piles sourced from an abandoned copper mine, and unnatural anthropogenic flows from the three BC Hydro dams present in the Jordan River system. The final stage of the research project focuses on assessing the adaptive capacity in the watershed to address the issues of concern outlined in the WUP. There is a current movement to create watershed organizations that are formally supported through new legislation in British Columbia, but questions remain about the capacities of these watershed communities to sustain such a formal institution and if these watershed communities are ready to successfully implement a local watershed governance model. The Gupta et al. (2010) six adaptive capacity dimensions provide a logical framework to explore if these capacities are present such that it could be expected that local watershed organizations would be effective as society adapts to more watershed-based governance approaches. Thirteen semi-structured interviews were conducted from October 2016 to February 2017. Interviews and observational data focused on the WUP process and prospective and current members of the Jordan Watershed Round Table (JWRT). The research evaluated whether these six adaptive capacity dimensions are present in watershed communities that have been subjected to water management processes, specifically the WUP program. Overall, the research concluded that the WUP has contributed to some adaptive capacity for watershed governance in the Jordan River, specifically on building the adaptive capacity dimensions: variety, learning capacity, room for autonomous change, leadership, and resources within the JWRT.Graduate