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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
241

Designing a cell phone application to alert and report drinking water quality to South Africans /

Brown, Deana. January 2009 (has links)
Thesis (M.S.)--Rochester Institute of Technology, 2009. / Typescript. Includes bibliographical references (leaves 50-51).
242

Drinking water disinfection byproduct formation assessment using natural organic matter fractionation and excitation-emission matrices

Johnstone, David W. January 2009 (has links)
Dissertation (Ph. D.)--University of Akron, Dept. of Civil Engineering, 2009. / "August, 2009." Title from electronic dissertation title page (viewed 9/30/2009) Advisor, Christopher M. Miller; Committee members, William Brian Arbuckle, George G. Chase, Annabelle M. Foos, William H. Schneider IV; Department Chair, Wieslaw Binienda; Dean of the College, George K. Haritos; Dean of the Graduate School, George R. Newkome. Includes bibliographical references.
243

From science to policy practice and public discourse : claimsmaking and chlorinated drinking water /

Driedger, Suzanne Michelle. January 2001 (has links)
Thesis (Ph.D.) -- McMaster University, 2001. / Includes bibliographical references (leaves 237-281). Also available via World Wide Web.
244

Groundwater arsenic concentrations and cancer incidence rates : a regional comparison in Oregon /

Fleming, Harmony S. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 65-70). Also available on the World Wide Web.
245

An investigation of interactions between bacteria & soil

Tomlinson, Steven. January 2008 (has links)
Thesis (PhD) - Environment and Biotechnology Centre, Faculty of Life and Social Sciences, Swinburne University of Technology, 2008. / Submitted for the degree of Doctor of Philosophy, Environment and Biotechnology Centre, Faculty of Life and Social Sciences, Swinburne University of Technology, 2008. Typescript. Includes bibliographical references (p. 215-247)
246

Nturlig förekomst av arsenik, bly och kadmium i enskilda dricksvattenbrunnar i norr- och västerbotten : Samband med jordarter. identifiering av riskområden samt följder av klimatförändringar

Hanna, Åbrink January 2018 (has links)
Clean and healthy drinking water is fundamental to human health. If the water comes from household drinking water wells, the quality of the water should be ensured by the property owner. Arsenic, lead and cadmium are substances that can cause health problems in elevated drinking water levels, making it important to control its occurrence. Several municipalities around the Skelleftefältet area in Norr- and Västerbotten County have been identified with elevated levels of these elements and the source is assumed to be the sulfide rich bedrock that dominates the area. This report aimed to investigate whether there was a correlation between elevated levels of arsenic, lead, and cadmium and soils. There was also reason to investigate future risk areas with increased erosion due to climate changes. Data from a total of 435 drinking water wells were gathered from Skellefteå and Piteå municipality and then compared with the soil at the sampling point. Wells within a radius of 1 km from areas with ravines or landslides were identified as risk areas. The result showed that about 14 % of the identified drinking water wells had elevated levels of arsenic. The concentrations in the samples and the soil types at the sampling points varied, and a correlation between a certain soil and elevated level could not be ensured. A few sampling points were identified in erosion-sensitive areas which are at major risk of major risk of increased mobility of metals.
247

DEVELOPING STATISTICAL CORRELATION OF VARIOUS TYPES OF BIRTH DEFECTS AND SPECIFIC CONTAMINANTS IN DRINKING WATER

Yang, Fan 01 December 2012 (has links)
Our research investigated the correlations of five key contaminants in drinking water in the State of Illinois with the incidence rates of three different categories of negative reproductive outcomes: birth defects, adverse pregnancy outcomes and preterm births. The five water contaminants included three agrichemical-based contaminants (atrazine, nitrate and nitrite) and two disinfectant byproducts (total trihalomethanes and haloacetic acids). We obtained nearly 38,000 measurements of the individual concentrations of these five contaminants from the Illinois Environmental Protection Agency (IEPA). These data, spanning over a five-year period (1998-2002), were collected from nearly 1,800 community water supplies (CWS) located in all 102 Illinois counties. The county-specific incidence rate data for the same time period for preterm births, seven groups of birth defects and seven groups of adverse pregnancy outcomes were collected from the Illinois Department of Public Health (IDPH). The traditional approach of establishing correlation of one explanatory variable at a time indicated that nitrate concentration in drinking water was statistically correlated to the incidence rate of only one category of negative reproductive outcome, i.e., birth defects. However, multiple regression analysis, which took into consideration all water contaminant data simultaneously, established statistical significance of the correlation between nitrate and all three categories of negative reproductive outcomes. Total trihalomethanes (TTHM) and haloacetic acids (HAA5) were also found to be the statistically significant explanatory variables for all three types of negative reproductive outcomes. Nitrite was found to be associated with adverse pregnancy outcomes and preterm births only; its correlation with birth defect rates could not be established at 80% confidence level. Atrazine was found to be among the significant explanatory variables for all three negative reproductive outcomes. However, its correlations with birth defect model developed using censored data and preterm birth model developed based on observed data were not statistically significant. Nearly 21.5%, 35.8% and 16.6% of the variabilities in incidence rates of different types of birth defects, adverse pregnancy outcomes and preterm births, respectively, were correlated to average concentrations of above mentioned five contaminants in community drinking water supplies. The monthly average concentrations of two of three agrichemical-based contaminants, i.e., atrazine and nitrate were significantly higher in SW(surface water)-based than GW(ground water)-based community water supplies. On the other hand, concentrations of both disinfectant byproducts and the other agrichemical-based contaminant, i.e., nitrite were significantly higher in GW-based water supplies. Further correlation analysis based on the actual observed concentration (excluding all 0 detections) was conducted utilizing SW-based atrazine and nitrate data and GW-based nitrite, TTHM and HAA5 data. All categories of negative reproductive outcomes were found significantly correlated with at least one type of water contaminants. The overall negative reproductive outcomes were correlated with nitrate, nitrite and atrazine. Birth defects specifically correlated with nitrate and TTHM, whereas adverse pregnancy outcomes were correlated with nitrate, nitrite and HAA5; preterm birth was correlated with the concentrations of nitrite, atrazine and TTHM. Further investigation indicated significant correlations among the explanatory variables (drinking water contaminants data), which is referred as multicollinearity. In such case, multiple linear regression based analysis may not provide reliable results. Partial least squares (PLS) approach of regression analysis was introduced into our study to overcome the multicollinearity problem. As much as 65.5% of the variability in the county-wide average concentrations of five contaminants in public drinking water supplies was explained by the 4 component PLS regression model, whereas only 7.7% of the incidence rates of different types of birth defects, adverse pregnancy outcomes and preterm births in various Illinois counties, were explained by PLS regression. Although, individual negative reproductive outcome model could be generated, the low R2 values indicated the poor reliability of these models. We attempted to corroborate our statistical analysis findings with the physiological effects of various water contaminants reported in the literature. It is well known that excessive exposure to any of the five key water contaminants may cause malfunction of organism or the immune system, reproduction, nervous and endocrine system and others, which may further result in potential risk of developing adverse effects. Nitrate and nitrite in drinking water associate to a certain extent with congenital malformations, such as central nervous system abnormalities, in human offsprings. Excessive exposure to atrazine is known to increase the risk of potential cardiovascular or reproductive system problems. A certain type of TTHM, i.e., BDCM are known to be associated with an increased risk of spontaneous miscarriage in pregnant women. It also may result in an increased risk of reproductive problem, such as fetal growth restriction.
248

Determinação de bisfenol A em água : uma investigação na cidade de Campo Grande - MS

Montagner, Émerson [UNESP] 15 October 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:35:07Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-10-15Bitstream added on 2014-06-13T19:05:18Z : No. of bitstreams: 1 montagner_e_dr_araiq.pdf: 2830486 bytes, checksum: 76237dd3b48ac6739011b71ca2d09a40 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O Bisfenol A (BFA) é um monômero formado por dois anéis fenólicos e empregado na produção de plástico policarbonato e resinas epóxi. O policarbonato é amplamente empregado na fabricação de vários produtos dos meios digitais (CD e DVD), recipientes reusáveis de alimentos e bebidas e muitos outros produtos. As resinas epóxi são usadas em circuitos elétricos, pinturas, adesivos, revestimentos protetores de latas de alimentos e bebidas e complexos dentários para obturações. Estudos revelaram que o BFA age nos organismos vivos com efeitos de desregulação endócrina, como um xenobiótico com ação estrogênica, provocando aumento da incidência de câncer de mama, queda da quantidade de esperma, diminuição da fertilidade, defeitos congênitos secundários à exposição fetal e outras alterações. O BFA chega ao ambiente aquático por inúmeras vias distintas como, por exemplo, vindo do lodo proveniente de esgoto, da descarga de esgotos domésticos e industriais, dos lixões e aterros sanitários não controlados. Neste trabalho, desenvolveu-se e validou-se um método para a determinação de BFA em águas superficiais e de abastecimento à população de Campo Grande - MS, utilizando-se extração em fase sólida EFS (cartuchos de fase polimérica Strata-X), derivação com N O-Bis-(trimetilsilil) trifluroacetamida (BSTFA) e detecção por cromatografia a gás acoplada à espectrometria de massas. A precisão e a exatidão do método foram avaliadas em de ensaios de recuperação. Recuperações variando de 91 a 113% com coeficientes de variação percentuais inferiores a 8,9% foram obtidos com limites de detecção e quantificação do método de 2,4 e 10 ng L-1, respectivamente. Também foi avaliada a conservação do BFA nos próprios cartuchos de EFS onde se observou que este analito pode ser armazenado por até 90 dias sem diferenças significativas entre o valor... / Bisphenol A (BPA) is a monomer consisting of two phenolic rings and employed in the production of polycarbonate plastic and epoxy resins. The polycarbonate is widely used in many manufactured products from digital media (CD and DVD), reusable containers food and beverages and many other products. Epoxy resins are used in electrical circuits, paints, adhesives, protective coatings for cans of food, drinks and complex dental fillings. Studies have shown that BPA acts in living organisms with the purpose of endocrine disrupting as a xenobiotic with estrogenic action, causing an increased incidence of breast cancer, decrease the amount sperm, fertility decreased, birth defects secondary to fetal exposure and other changes. BPA reaches the aquatic environment by several distinct pathways, for example, coming from the sludge sewage, discharge of domestic sewage and industrial waste dumps and the landfills. In this work, we developed and validated a method for the determination of BPA in surface water and supply population of Campo Grande – MS was developmente ande validated using solid phase extraction SPE (polymeric phase cartridges Strata-X), derivatized with N-O-Bis (trimethylsilyl) trifluroacetamide (BSTFA) and detection by gas chromatography coupled to mass spectrometry. The precision and accuracy of method were evaluated through recovery experiments. Recoveries ranging from 91-113% with coefficients of variation lower to 8.9% were obtained with limits of detection and quantification of 2.4 and 10 ng L-1, respectively. We also analyzed the estability of BPA in individual cartridges SPE where it was observed that the analyte can be stored for up to 90 days without significant differences between the determined and the value taken as true. The leaching of BPA from PVC pipes was investigated coming to conclusions that this is a source contamination of water by this important endocrine... (Complete abstract click electronic access below)
249

Treatment of saline solutions using air gap membrane distillation (AGMD)

Alkhudhiri, Abdullah Ibrahim January 2013 (has links)
No description available.
250

Monitoring heavy metals in private drinking water near industrial activity in Kosovo

Jansson, Victoria January 2018 (has links)
Exposure to heavy metals around the world is practically unavoidable due to their extensive use and spread in the environment. This is especially critical due to the metals’ toxicity and detrimental effects on human health. Rural inhabitants in less developed countries in Europe near industrial local polluters are especially exposed. Leachates from industrial wastes may add heavy metal pollution to surrounding groundwater aquifers. Both industrial pollution and rain runoff poses extensive risks for private wells. These wells provide a large part of the drinking water supplies for Kosovo’s inhabitants. The aim of this study is to investigate how a nickel (Ni) refining industry’s slag hill is affecting the drinking water quality in surrounding neighbours private drinking water supplies. To do this 10 samples with increasing distance from the industrial slag hill were collected and analysed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Chromium (Cr), Ni and lead (Pb) were below guideline and limit values in the well water drinking supplies. Rain runoffs increased the concentrations of aluminium (Al), Ni and Pb, in wells where rainwater leaked in. This was however not the case for Cr. Highest Cr concentrations were found in clear (unpolluted by rain runoff) well waters, southeast of a local open pit mining area. This study shows that the Ni refinery and slag hill do not currently risk contaminating local drinking water wells above guideline and limit values. However, there are indications that local mining activity may pose a larger risk concerning Cr leakage to the private wells. Further groundwater monitoring is needed focusing on this area to investigate potential and actual sources of pollution.

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