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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.
1

Advancing Bioaccumulation Modeling and Water Sampling of Ionogenic Organic Chemicals

Cao, Xiaoshu 24 June 2014 (has links)
Although many commercial chemicals can dissociate, the study of the biological and environmental fate of ionogenic organic chemicals (IOCs) is still in its infancy. Uptake of the veterinary drug diclofenac in vultures and cattle was successfully simulated with a newly developed physiologically-based pharmacokinetic model for IOCs, lending credence to diclofenac’s proposed role in South Asian vulture population declines. Proteins and phospholipids rather than total lipids control the tissue distribution of diclofenac. A method was developed to simultaneously extract neutral and acidic pesticides and benzotriazoles from water samples with recoveries ranging 70-100%. This method was applied to samples from a laboratory calibration experiment of the Polar Organic Chemical Integrative Sampler. The sampler had higher uptake for neutral and acidic pesticides when filled with triphasic sorbent admixture and OASIS MAS sorbent, respectively. While either sorbent can also be applied for methylated benzotriazoles, neither is capable of quantitatively sampling all three compound groups.
2

Advancing Bioaccumulation Modeling and Water Sampling of Ionogenic Organic Chemicals

Cao, Xiaoshu 24 June 2014 (has links)
Although many commercial chemicals can dissociate, the study of the biological and environmental fate of ionogenic organic chemicals (IOCs) is still in its infancy. Uptake of the veterinary drug diclofenac in vultures and cattle was successfully simulated with a newly developed physiologically-based pharmacokinetic model for IOCs, lending credence to diclofenac’s proposed role in South Asian vulture population declines. Proteins and phospholipids rather than total lipids control the tissue distribution of diclofenac. A method was developed to simultaneously extract neutral and acidic pesticides and benzotriazoles from water samples with recoveries ranging 70-100%. This method was applied to samples from a laboratory calibration experiment of the Polar Organic Chemical Integrative Sampler. The sampler had higher uptake for neutral and acidic pesticides when filled with triphasic sorbent admixture and OASIS MAS sorbent, respectively. While either sorbent can also be applied for methylated benzotriazoles, neither is capable of quantitatively sampling all three compound groups.
3

Nitrate Contamination Potential in Arizona Groundwater: Implications for Drinking Water Wells

Uhlman, Kristine, Artiola, Janick 07 1900 (has links)
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.
4

DEVELOPMENT AND APPLICATION OF METHODS FOR STABLE WATER ISOTOPE SAMPLING FROM A LOW GRADIENT CANAL

Unknown Date (has links)
Stable isotopes of water are used as tracers for characterizing surface water/groundwater interactions. Gaps in sampling protocol for these tracers in low gradient canals limits their use in studies of canal-groundwater exchanges. Several sampling methods were developed to determine the temporal and spatial isotopic variation in a canal. The influence of a flow control gate on isotopic composition and the sensitivity of isotope mixing calculations to choice of sampling method were also evaluated. There was little variability in the isotopic composition of the canal along a cross section perpendicular flow. Some variation occurred monthly and seasonally. The greatest variability occurred between the upstream and downstream side of the flow control gates when the gates were closed. Mixing calculations were not sensitive to the choice of sampling method. This study shed light on isotope sampling methods in canals for canal-groundwater interactions studies. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2019. / FAU Electronic Theses and Dissertations Collection
5

The Small Volume Autonomous Water Sampler (SVAWS): An Innovative, Cost- Effective, Adaptable Protocol

Fitzgerald, Nicholas B 16 January 2014 (has links)
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.
6

An Analysis of Heavy Metals in Sediment and Water of Southwestern Costa Rican Watersheds Using ICP-MS

Lerner, Moriah I. 01 January 2015 (has links)
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.
7

Estudo da macrófita Typha sp como material adsorvente na remoção das espécies metálicas Cd (II), Cu (II), Cr (III) e Zn (II) em meio aquoso / Study of the Typha sp macrophyte as adsorbent material in the removal of Cd (II), Cu (II), Cr (III) and Zn (II) metal species in aqueous medium

Rabelo, Joseane 31 July 2018 (has links)
Submitted by Joseane Rabelo (josyrabb@gmail.com) on 2018-08-18T17:55:00Z No. of bitstreams: 1 RABELO, J_ME.pdf: 3506789 bytes, checksum: 945c66fa4447e66037b3f637d1c9a0c8 (MD5) / Approved for entry into archive by Ana Carolina Gonçalves Bet null (abet@iq.unesp.br) on 2018-08-20T13:46:21Z (GMT) No. of bitstreams: 1 rabelo_j_me_araiq_int.pdf: 3348948 bytes, checksum: 2b3987dc3b3fc2f4ef2a5f330e2b95c0 (MD5) / Made available in DSpace on 2018-08-20T13:46:21Z (GMT). No. of bitstreams: 1 rabelo_j_me_araiq_int.pdf: 3348948 bytes, checksum: 2b3987dc3b3fc2f4ef2a5f330e2b95c0 (MD5) Previous issue date: 2018-07-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Os biossorventes provenientes de materiais lignocelulósicos são alternativas de baixo custo e mais sustentável para o meio ambiente na remoção das espécies metálicas. Neste caminho, o presente trabalho descreve o uso da macrófita, Typha sp, também conhecida como taboa, para remover as espécies metálicas Cu (II), Cr (III), Cd (II) e Zn (II) em amostras aquosas. Caracterizou-se inicialmente a macrófita Typha sp utilizando as técnicas analíticas como: espectroscopia na região do infravermelho (FT-IR), análise elementar de N e Ressonância magnética nuclear (RMN) de 13C, microscopia eletrônica de varredura (MEV), espectroscopia de energia dispersiva de raio X (EDS) e análise de área superficial utilizando adsorção de N2. As características adsortivas da Typha sp foram estabelecidas através de experimentos em batelada em função do pH, o tempo de contato e a concentração. As micrografias da Typha sp apresentou-se partículas com morfologia heterogênea, irregular em formato de bastão. O FT-IR e o RMN 13C confirmaram a presença de grupos funcionais como COOH, NH2 e S=C=N, que possuem pares de elétrons não ligantes e que coordenam com as espécies metálicas. A área superficial específica da Typha sp foi menor que 1 m2/g, característico de materiais não porosos. Os experimentos de adsorção mostraram que o pH 5,5 favorece a adsorção das espécies metálicas em estudo. A cinética de adsorção é rápida, sendo menor que 15 min, ajustando aos dados experimentais do modelo cinético de pseudo-segunda ordem. A capacidade máxima de adsorção determinada experimentalmente foi de 9,48, 6,55, 3,01 e 9,52 mg/g para Cr (III), Cu (II), Zn (II) e Cd (II). Respectivamente, os dados obtidos nas isotermas foram aplicados ao modelo Langmuir, cujos valores do coeficiente linear foi maior que 0,95, comprovando o bom ajuste dos dados a este modelo. A adsorção na presença de um segundo íon teve maior interferência para as espécies metálicas de Cu (II) e Zn (II) diminuindo a adsorção em 30 %. Após a determinação das caracteristica adsortivas da Typha sp, essa foi utilizada como suporte sólida na estração em fase sólida. Os parâmetros otimizados no sistema em fluxo para utilizar a Typha sp na extração em fase sólida (SPE) foram: vazão, massa, volume da amostra, concentração do ácido e o volume do eluato, obtendo uma recuperação acima de 78 %. A aplicação nas amostra do Rio Tietê e Paranapanema foram satisfatórias para as espécies Cu (II), Cd (II) e Zn (II), porém a recuperação do Cr (III) foi nula, devido a interferência da matriz. A Typha sp possui grande potencial para ser utilizada como biossorvente na adsorção das espécies metálicas em estudo, devido ao baixo custo do material e a elevada capacidade de adsorção das espécies metálicas. / Biosorbents from lignocellulosic materials are low cost alternatives and more environmentally sustainable in the removal of metal species. In this way, the present work describes the use of the macrophyte, Typha sp, also known as Taboa, to remove the Cu (II), Cr (III), Cd (II) and Zn (II) metal species in aqueous samples. Typha sp macrophyte was initially characterized using analytical techniques such as infrared spectroscopy (FT-IR), elemental analysis of N and 13C nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), energy spectroscopy dispersive X-ray diffraction (EDS) and surface area analysis using N2 adsorption. The adsorptive characteristics of Typha sp were established through batch experiments as a function of pH, contact time and concentration. The micrographs of the Typha sp presented particles with heterogeneous morphology, irregular in stick format. FT-IR and 13C NMR confirmed the presence of functional groups such as COOH, NH2 and S = C = N, which have non-binding electron pairs and coordinate with the metallic species. The specific surface area of Typha sp was less than 1 m2/g, characteristic of non-porous materials. The adsorption experiments showed that pH 5.5 favors adsorption of the metal species under study. The kinetics of adsorption is fast, being less than 15 min, adjusting to the experimental data of the kinetic model of pseudo-second order. The maximum adsorption capacity determined experimentally was 9.48, 6.55, 3.01 and 9.52 mg/g for Cr (III), Cu (II), Zn (II) and Cd (II). The data obtained in the isotherms were applied to the Langmuir model, whose linear coefficient values were greater than 0.95, confirming the good fit of the data to this model. The adsorption in the presence of a second ion had greater interference for the Cu (II) and Zn (II) metal species, reducing the adsorption by 30%. After the determination of the adsorptive characteristics of Typha sp, this was used as solid support in the solid phase separation. The optimized parameters in the flow system to use Typha sp in the solid phase extraction (SPE) were: flow, mass, sample volume, acid concentration and eluate volume, obtaining a recovery above 78%. The Cu (II), Cd (II) and Zn (II) species were satisfactory for the Tietê and Paranapanema samples, but the Cr (III) recovery was null due to matrix interference. Typha sp has great potential to be used as a biosorbent in the adsorption of the metal species under study, due to the low cost of the material and the high adsorption capacity of the metallic species. / CAPES
8

Methods and Devices for Assessment of Fiprole Pesticides in Engineered Waterways

January 2015 (has links)
abstract: This dissertation focused on the development and application of state-of-the-art monitoring tools and analysis methods for tracking the fate of trace level contaminants in the natural and built water environments, using fipronil as a model; fipronil and its primary degradates (known collectively as fiproles) are among a group of trace level emerging environmental contaminants that are extremely potent arthropodic neurotoxins. The work further aimed to fill in data gaps regarding the presence and fate of fipronil in engineered water systems, specifically in a wastewater treatment plant (WWTP), and in an engineered wetland. A review of manual and automated “active” water sampling technologies motivated the development of two new automated samplers capable of in situ biphasic extraction of water samples across the bulk water/sediment interface of surface water systems. Combined with an optimized method for the quantification of fiproles, the newly developed In Situ Sampler for Biphasic water monitoring (IS2B) was deployed along with conventional automated water samplers, to study the fate and occurrence of fiproles in engineered water environments; continuous sampling over two days and subsequent analysis yielded average total fiprole concentrations in wetland surface water (9.9 ± 4.6 to 18.1 ± 4.6 ng/L) and wetland sediment pore water (9.1 ± 3.0 to 12.6 ± 2.1 ng/L). A mass balance of the WWTP located immediately upstream demonstrated unattenuated breakthrough of total fiproles through the WWTP with 25 ± 3 % of fipronil conversion to degradates, and only limited removal of total fiproles in the wetland (47 ± 13%). Extrapolation of local emissions (5–7 g/d) suggests nationwide annual fiprole loadings from WWTPs to U.S. surface waters on the order of about one half to three quarters of a metric tonne. The qualitative and quantitative data collected in this work have regulatory implications, and the sampling tools and analysis strategies described in this thesis have broad applicability in the assessment of risks posed by trace level environmental contaminants. / Dissertation/Thesis / Doctoral Dissertation Civil and Environmental Engineering 2015
9

Verktyg för effektiviserad provtagning på råvatten : Ett arbete utfört i samarbete med Laholmsbuktens VA & miljöförvaltningen i Halmstad

Johansson, Frida, Larsen-Spasojevic, Nina January 2018 (has links)
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).
10

Estudo da macrófita Typha sp como material adsorvente na remoção das espécies metálicas Cd (II), Cu (II), Cr (III) e Zn (II) em meio aquoso /

Rabelo, Joseane. January 2018 (has links)
Orientador: Gustavo Rocha de Castro / Banca: Margarida Juri Saeki / Banca: Nelson Consolin Filho / Resumo: Os biossorventes provenientes de materiais lignocelulósicos são alternativas de baixo custo e mais sustentável para o meio ambiente na remoção das espécies metálicas. Neste caminho, o presente trabalho descreve o uso da macrófita, Typha sp, também conhecida como taboa, para remover as espécies metálicas Cu (II), Cr (III), Cd (II) e Zn (II) em amostras aquosas. Caracterizou-se inicialmente a macrófita Typha sp utilizando as técnicas analíticas como: espectroscopia na região do infravermelho (FT-IR), análise elementar de N e Ressonância magnética nuclear (RMN) de 13C, microscopia eletrônica de varredura (MEV), espectroscopia de energia dispersiva de raio X (EDS) e análise de área superficial utilizando adsorção de N2. As características adsortivas da Typha sp foram estabelecidas através de experimentos em batelada em função do pH, o tempo de contato e a concentração. As micrografias da Typha sp apresentou-se partículas com morfologia heterogênea, irregular em formato de bastão. O FT-IR e o RMN 13C confirmaram a presença de grupos funcionais como COOH, NH2 e S=C=N, que possuem pares de elétrons não ligantes e que coordenam com as espécies metálicas. A área superficial específica da Typha sp foi menor que 1 m2/g, característico de materiais não porosos. Os experimentos de adsorção mostraram que o pH 5,5 favorece a adsorção das espécies metálicas em estudo. A cinética de adsorção é rápida, sendo menor que 15 min, ajustando aos dados experimentais do modelo cinético de pseudo-segun... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Biosorbents from lignocellulosic materials are low cost alternatives and more environmentally sustainable in the removal of metal species. In this way, the present work describes the use of the macrophyte, Typha sp, also known as Taboa, to remove the Cu (II), Cr (III), Cd (II) and Zn (II) metal species in aqueous samples. Typha sp macrophyte was initially characterized using analytical techniques such as infrared spectroscopy (FT-IR), elemental analysis of N and 13C nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), energy spectroscopy dispersive X-ray diffraction (EDS) and surface area analysis using N2 adsorption. The adsorptive characteristics of Typha sp were established through batch experiments as a function of pH, contact time and concentration. The micrographs of the Typha sp presented particles with heterogeneous morphology, irregular in stick format. FT-IR and 13C NMR confirmed the presence of functional groups such as COOH, NH2 and S = C = N, which have non-binding electron pairs and coordinate with the metallic species. The specific surface area of Typha sp was less than 1 m2/g, characteristic of non-porous materials. The adsorption experiments showed that pH 5.5 favors adsorption of the metal species under study. The kinetics of adsorption is fast, being less than 15 min, adjusting to the experimental data of the kinetic model of pseudo-second order. The maximum adsorption capacity determined experimentally was 9.48, 6.55, 3.01 and 9.52 mg/g fo... (Complete abstract click electronic access below) / Mestre

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