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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.
111

Risk assessment: to surface water in Kallerstadsdiket and Stångån near the closed Kallerstad landfill, Linköping.

Karpestam, Einat January 2017 (has links)
Kallerstaddeponin användes aktivt för deponering av avfall mellan 1950 och 1973. Nedlagda deponier bör dock bedömas med avseende på den risk de utgör för miljö och hälsa. I denna studie, jämfördes nivåerna av zink, nickel, arsenik, koppar, ammoniak, TOT-N och TOC i deponins huvudrecipient, Kallerstadsdiket, med de gränsvärden som fastställts av Havs- och vattenmyndigheten. Därefter uppskattades Kallerstaddeponins direkta bidrag till föroreningsnivån. Slutligen, beräknades spridningsrisken, nämligen den föroreningsbelastning som flödar från Kallerstadsdiket till Stångån, som är en andra recipient. Zink, nickel och koppar visade låga nivåer och låg risk på alla provtagningsstationer. Ammoniak och arsenik visade högre nivåer och en potentiell risk för negativa effekter. Detta innebär att Kallerstadsdikets ytvatten inte klassificeras att uppnå "bra" status, även om den direkta rollen som Kallerstaddeponin spelar är tveksam i detta fall. Beräkningarna tyder på att Kallerstaddeponin tillför arsenik och TOC till föroreningsnivåerna, även om det är i små mängder. Risken för spridning av föroreningar till Stångån uppskattades vara låg. Utspädningsfaktorn uppskattades till att vara 1:320 och de ytterligare föroreningsnivåerna som härstammar från Kallerstadsdiket är låga i förhållande till de uppmätta nivåerna i Stångån. Den aktuella studien har många osäkerheter som huvudsakligen är relaterade till tillgängligheten av data. Det rekommenderas därför att tillämpa en mer fullständig provtagning med lämpliga parametrar (t.ex. pH, DOC, Ca och temperatur) i alla provtagningsstationer. Helst skulle det vara önskvärt med provtagning varje vecka under en period av ett år och sedan åter bedöma risken för att få en mer tillförlitlig uppskattning av deponins bidrag. / Kallerstad landfill was in use between 1950 and 1973. Nonetheless, assessment of closed landfills and their risk to the environment and health is required. Firstly, the levels of zinc, nickel, arsenic, copper, ammonia, TOT-N and TOC in the surface water of the main recipient Kallerstadsdiket, were compared to cut-off levels given by the Swedish Agency for Marine and Water Management. Then, the direct contribution of Kallerstad landfill to the contamination level was estimated. Finally, the contamination load that flows from Kallerstadsdiket to Stångån, which is a second recipient with high natural value, was estimated. Zinc, nickel and copper showed low levels and low risk at all sampling stations. Ammonia and arsenic showed higher levels and a potential risk of adverse effects. As a result, the surface water in Kallerstadsdiket could not be classified to reach ‘good’ status, although the direct role that Kallerstad landfill plays is doubtful. Calculations suggest that Kallerstad landfill does add arsenic and TOC to the contamination levels, although in small amounts. The risk of spread of contaminants to Stångån was estimated to be low. The additional contamination levels stemming from Kallerstadsdiket are lower than the levels measured in Stångån. The dilution factor was estimated to be 1:320. Nevertheless, the current study has many uncertainties that are mainly related to data availability. It is therefore recommended to apply a more complete sampling scheme with the appropriate parameters (e.g., pH, DOC, Ca, and temperature) in all sampling stations. Ideally it would be plausible to sample every week for a period of a year and then reassess the risk, as well as to get a more reliable approximation of the contribution of the landfill itself.
112

A conceptual understanding of groundwater recharge processes and surface-water/ groundwater interactions in the Kruger National Park

Petersen, Robin Marc January 2012 (has links)
>Magister Scientiae - MSc / In the Kruger National Park (KNP) which is the flagship conservation area in South Africa, the impact on groundwater should be kept to a minimum as groundwater plays a vital role in sustaining ecosystem functioning and sustaining baseflow to streams and rivers. For this reason groundwater has been recognized as one of the environmental indicators that need to be monitored. The KNP has adopted a Strategic Adaptive Management (SAM) approach with clear ecosystem management goals. The achievement of these goals is evaluated by using environmental indicators. These indicators are evaluated against thresholds of potential concern (TPC). TPCs are a set of boundaries that together define the spatiotemporal conditions for which the KNP ecosystem is managed. TPCs are essentially upper and lower limits along a continuum of change in selected environmental indicators. Historically, groundwater recharge and surface water interaction with rivers has tended to be overlooked in the KNP. This study proposes a conceptual model of groundwater recharge processes in the KNP, defining when and how groundwater recharge occurs. Two methods were used, the Cumulative Rainfall Departure (CRD) and stable isotopes of ²H and ¹⁸O. An adapted version of the CRD which incorporates a long and short term memory of the system was used to identify possible recharge processes. Further, using the CRD method a reliable reconstruction of the long term groundwater level trends are simulated using monthly rainfall totals with reference to the average rainfall over the entire time series 1936-2009. The stable isotope of ²H and ¹⁸O samples from cumulative rainfall samplers, surfacewater (streams and rivers) and groundwater from boreholes were collected monthly for approximately one year (May 2010 to July 2011). The isotope composition of the groundwater was used to establish whether recharge was immediate or delayed. Additionally, the isotopic composition of surface-water from rivers and streams were compared to that of groundwater to identify surface-water interactions. Groundwater recharge in KNP occurs during the rainy summer months (December to March) and very little to none during the dry winter season (April to September). Recharge takes place during rainfall sequences 100mm or more. The stable isotope records collected from cumulative rainfall, groundwater and surface water (streams and rivers) indicate that groundwater experiences evaporation prior to infiltration. As the KNP experiences high evaporation rates, insignificant rainfall sequences contribute little or zero to recharge. The CRD analysis of groundwater level fluctuations shows that recharge to the aquifers respond to dry and wet cycles that last for 6 to 14 years. The KNP experienced several periods of below-average rainfall and hence no significant recharge took place to the basement aquifers. During a normal rainy season the water levels rise somewhat then starts receding again. It is only during major rainfall events that may occur every 100yrs to 200yrs causing the aquifers to fully recharge. This was perfectly illustrated by the high groundwater levels after the 2000 major rainfall event that recharged the aquifers fully. During below average rainfall years the overall water level trend is drastically declining. The system experiences higher natural losses than gains due to outflow of groundwater to streams and rivers. The KNP is divided down the center by two geological formations, granites along the west and basalts along the east. The combination of the CRD model and the stable isotopic analysis suggest that the dominant recharge processes that occur in the southern region of the KNP are direct recharge via piston flow and indirect recharge via preferred pathways particularly streams and rivers. Along the eastern half of the KNP on the Basalts and Rhyolite direct recharge via piston flow are dominant. Groundwater is not recharged via small streams and rivers (Sweni and Mnondozi Rivers) as it was found that at these particular sites these rivers are detached and do not interact with groundwater. Along the western granitic areas the dominant recharge process are indirect recharge. Recharge takes place via preferred pathways particularly streams and rivers. It was found that ephemeral rivers (Nwatsisonto River) act as sinks for groundwater recharge and influent-effluent conditions are experienced along seasonal rivers (Mbyamiti River). The large perennial Sabie and its tributary the Sand River are consistently fed by groundwater, above all maintaining base flow during the dry season. These rivers act as basin sinks receiving groundwater discharge all year round. Using the stable isotope composition of rainfall, surface-water and groundwater to act as a natural tracer, in combination with the CRD method proved invaluable to confirm the plausible recharge processes. The study provided a conceptual understanding of the groundwater system in the KNP forming the foundation to developing acceptable limits (TPCs) of the groundwater levels in the KNP. The model will serve as a guide for the recharge processes and for deciding on the location and time frames for data collection to ultimately set TPCs for groundwater in the KNP to sustainably manage the resource.
113

Target and Non-target Techniques for the Quantitation of Drugs of Abuse, Identification of Transformation Products, and Characterization of Contaminants of Emergent Concern by High Resolution Mass Spectrometry

Heuett, Nubia Vanesa 29 June 2015 (has links)
Development and application of target and non-target techniques for routine analysis, identification of transformation products, and characterization of unknown compounds in water matrices using liquid-chromatography high-resolution mass spectrometry (HRMS) were explored in this dissertation. A novel analytical method based on online-SPE-LC-HRMS was developed for the detection of 18 drugs of abuse (DOAs) in raw sewage water from a college campus. Results showed the presence of 14 DOAs for which amphetamine and 11-nor-9-carcoxy-THC (THC metabolite) were the most prevalent and had the highest potential consumption rates. A second study dedicated to the identification of transformation products (TPs) generated from DOAs was conducted using a combination of HR-MS/MS and metabolic identification and structural elucidation software. Findings confirmed the presence of multiple phase I and II DOA TPs (n=35) in raw sewage influents. Concentrations of all TPs were estimated based on the parent DOAs response factors, and used to calculate the percent mole fraction contributions of each TP to the parent concentrations. High abundance and frequency (compared to the parent drug) was determined for 9 of the TPs coming from drugs like oxycodone, morphine, codeine, methadone, LSD, cocaine, and MDEA. Non-target analysis using HRMS was explored as a tool to characterize, and compare a series of interconnected water matrices along a river system. Several thousands of formulae were generated using automated heuristic rules from the full-scan acquisition at 140,000 resolution. Samples were part of a trajectory covering upstream, effluent, effluent mixing zone, downstream, drinking water intake, and treated drinking water locations. Graphical representations of the data were used to evaluate commonalities among the system. Using this approach, a total of 64 recalcitrant components were identified throughout the samples downstream of the effluent release point. Using a combination of MS/MS and computer-aid software techniques 4 out of the 64 compounds were tentatively confirmed. In addition, comparison of drinking water intake and finalized treated drinking water sites showed the presence of 1,152 chemical entities that were common to both locations; and 1,857 that were unique to the treated drinking water. Therefore, this non-target technique could be used to identify the potential formation of treatment byproducts.
114

Ecohydrology, Evapotranspiration and Hydrogeochemistry of Carbonate Mangrove Wetlands

Lagomasino, David 21 January 2014 (has links)
Coastal environments can be highly susceptible to environmental changes caused by anthropogenic pressures and natural events. Both anthropogenic and natural perturbations may directly affect the amount and the quality of water flowing through the ecosystem, both in the surface and subsurface and can subsequently, alter ecological communities and functions. The Florida Everglades and the Sian Ka’an Biosphere Reserve (Mexico) are two large ecosystems with an extensive coastal mangrove ecotone that represent a historically altered and pristine environment, respectively. Rising sea levels, climate change, increased water demand, and salt water intrusion are growing concerns in these regions and underlies the need for a better understanding of the present conditions. The goal of my research was to better understand various ecohydrological, environmental, and hydrogeochemical interactions and relationships in carbonate mangrove wetlands. A combination of aqueous geochemical analyses and visible and near-infrared reflectance data were employed to explore relationships between surface and subsurface water chemistry and spectral biophysical stress in mangroves. Optical satellite imagery and field collected meteorological data were used to estimate surface energy and evapotranspiration and measure variability associated with hurricanes and restoration efforts. Furthermore, major ionic and nutrient concentrations, and stable isotopes of hydrogen and oxygen were used to distinguish water sources and infer coastal groundwater discharge by applying the data to a combined principal component analysis-end member mixing model. Spectral reflectance measured at the field and satellite scales were successfully used to estimate surface and subsurface water chemistry and model chloride concentrations along the southern Everglades. Satellite imagery indicated that mangrove sites that have less tidal flushing and hydrogeomorphic heterogeneity tend to have more variable evapotranspiration and soil heat flux in response to storms and restoration. Lastly, water chemistry and multivariate analyses indicated two distinct fresh groundwater sources that discharge to the phosphorus-limited estuaries and bays of the Sian Ka’an Biopshere Reserve; and that coastal groundwater discharge was an important source for phosphorus. The results of the study give us a better understanding of the ecohydrological and hydrogeological processes in carbonate mangrove environments that can be then be extrapolated to similar coastal ecosystems in the Caribbean.
115

Utvärdering av en sjö- och borrhålsbaserad värmepumpsanläggning i Stockholm

Lomrén, Erik January 2017 (has links)
Lågtempererade värmekällor som ytvatten och borrhålslager kan i samverkan med en värmepump ses som outnyttjade energikällor. En sjö- och borrhålsbaserad anläggning kan ha en hög total effektivitet om både värme och kylbehov finns och en stor fördel är att frikyla kan användas från sjö och borrhål under delar av året. Kungsbrohuset byggdes 2008 - 2010 med målsättningen att bli världens mest energieffektiva kontorsbyggnad. Mer specifikt var målsättningen att köpt energi skulle vara hälften av boverkets regler. Av den totala bruksarean på 27 000 m2 utgörs ca 19 500 m2 av kontorsyta. Anläggningen värms och kyls huvudsakligen av en värmepump med en värmeeffekt på 350 kW. Vintertid används värmepumpen för både värme och kyla då ett stort kylbehov även finns under uppvärmningssäsongen till serverrum mm. När värmepumpen inte räcker till så används fjärrvärme och fjärrkyla/sjökyla för att täcka behovet. Vid byggnationen installerades en ledning mellan kungsbrohuset och centralstationen för att på centralstationen utnyttja frikyla från sjön samtidigt som kungsbrohuset fick möjligheten att utnyttja värmen i köldbärarreturen. Målet med studien var att utvärdera anläggningen med fokus på tre huvudsakliga frågor. Att undersöka om värmepumpen har högsta möjliga temperatur på förångningssidan vintertid var den första. Den andra frågan var om frikyla från sjön utnyttjades optimalt. Den tredje frågan var att jämföra den projekterade energianvändningen med det verkliga utfallet. Studien utfördes genom besiktningar på plats, insamling av energistatistik samt att studera anläggningen genom driftdator, driftkort, flödesscheman etc. Vintertid så har den egna köldbärarreturen använts nästan uteslutande som värmekälla till värmepumpen då dess temperatur är högre än borrhålslagrets. Utnyttjandet av frikyla från sjön har inte fungerat optimalt då fjärrkyla har använts under vintermånaderna trots att sjöns temperatur är låg. Detta kan åtgärdas genom omprogrammering av villkor för aktivering av frikylan. Jämförelsen mellan projekterad köpt fastighetsenergi på 47 kWh/m2, år med det verkliga utfallet visade att användningen är något högre i verkligheten och hamnade på 55 kWh/m2, år efter att processkylan räknats bort då den inte räknas som fastighetsenergi. Anläggningen är totalt sett väldigt effektiv och har en mycket låg användning av köpt energi. Att kylbehov finns även vintertid gör att värmepumpens effektivitet blir maximal då nyttig energi utnyttjas på båda sidorna.
116

Assessment of Submerged Vegetation as Indicators of Irgarol Contamination

Fernandez, Melissa V 13 September 2010 (has links)
Irgarol 1051 is a common antifoulant toxic to certain marine organisms. Submerged aquatic vegetation (SAV) are exposed to this herbicide when it leaches into the marine environment from painted structures, making SAVs ideal candidates to function as sentinel indicator of contamination. In the initial stage of this study, Coconut Grove and Key Largo Harbor were assessed for environmental exposure to Irgarol. Water, sediment and SAVs were collected, the latter two subject to automated solid phase extraction, and all samples analyzed by GC/MS-SIM for Irgarol and its metabolite, M1. Of the vegetation analyzed, Halodule and Syringodium had the highest capacity to bioaccumulate Irgarol and M1. The root system and leaf contributed negligibly and significantly, respectively, to Irgarol uptake. In the final stage, a transplant between Coconut Grove and Chicken Key showed that the biota Thalassia and Halodule were able to uptake and depurate Irgarol, respectively, over a period of 30 days.
117

Development of an Integrated Surface and Subsurface Model of Everglades National Park

Cook, Amy 28 March 2012 (has links)
An integrated surface-subsurface hydrological model of Everglades National Park (ENP) was developed using MIKE SHE and MIKE 11 modeling software. The model has a resolution of 400 meters, covers approximately 1050 square miles of ENP, includes 110 miles of drainage canals with a variety of hydraulic structures, and processes hydrological information, such as evapotranspiration, precipitation, groundwater levels, canal discharges and levels, and operational schedules. Calibration was based on time series and probability of exceedance for water levels and discharges in the years 1987 through 1997. Model verification was then completed for the period of 1998 through 2005. Parameter sensitivity in uncertainty analysis showed that the model was most sensitive to the hydraulic conductivity of the regional Surficial Aquifer System, the Manning's roughness coefficient, and the leakage coefficient, which defines the canal-subsurface interaction. The model offers an enhanced predictive capability, compared to other models currently available, to simulate the flow regime in ENP and to forecast the impact of topography, water flows, and modifying operation schedules.
118

Analysis of the bio-physicochemical quality of surface and ground water in the Tubatse Municipality

Mathipa, Morongwa Mary January 2016 (has links)
Thesis (M. Sc. (Microbiology)) -- University of limpopo, 2016 / Human activities are known to be the major contributors to contamination of natural water sources. This becomes a serious health risk when the communities rely on the same water sources for their household water needs. The current study investigated the bio-physicochemical quality of surface and ground waters found in a mining area in the Tubatse locality, for their suitability for drinking and other household use. The bacteriological analyses of surface waters showed dominance by genera of the phylum Proteobacteria, followed by Actinobacteria and Firmicutes. The isolates included the genera Aeromonas, Pseudomonas, Cronobacter, Acinetobacter, Enterobacter, Pantoea, Serratia, Bordetella, Kocuria and Streptococcus. This dominance pattern is proportionately similar to the pattern reported on human skin and of gut biota. Enterobacter spp. were the predominant species in the surface waters, followed by Bordetella spp. With regard to ground water, one sample was laden with coliforms whereas the other sample was free of coliforms. Physical quality parameters such as turbidity, colour and (total suspended solids) TSS of the surface and ground water samples were compliant with the set standards for drinking water according to South African water quality guidelines (2005). The concentrations of Zn, [SCN-], Cr, Co, Fe, Ni, Cu, H2O2, Cl2 were determined in the surface and ground waters in dry and wet seasons as well. A non-significant decrease in the levels of Cl2 and [SCN-] and an increase in TDS and Cr were observed in the wet season. All metal and chemical levels in surface and ground water, except Cr, were lower than permitted concentration for drinking water. However the concentrations of Zn, Fe and Co exceeded the normal expected concentrations of < 3.5 μg/L, 0.5 mg/L, < 0.01 mg/L and < 5 μg/L respectively. The sediments and soil samples were digested with aqua regia for Cu, Cr, Fe, Co and Zn analyses. An increase in the levels of Zn, Cr and Co in the wet season was observed. The concentrations of the heavy metals such as Co, Cu and Cr were higher in sediments at the sampling points closer to the mining sites. Cytotoxicity assay was performed with different concentrations, as detected in the water and sediment samples, of Zn, [SCN-], Cr, Co, and Fe on C2C12 (mammalian) cells. An increase in viable cells was observed after treatment with Cr (0.2, 0.45 and 0.9 mg/L), Zn and Fe (1.0 and 2 mg/L), Co (2, 5 and 10 mg/L). Only cells treated with SCN- (3.3, 5.4 and 7.2 mg/L) exhibited a significant decrease in viability. These results demonstrate that the water in the Tubatse municipality is not suitable for drinking and other household purposes without prior treatment which will remove contaminating microorganisms and chemicals and heavy metals.
119

EVALUATION OF PERFLUOROALKYL ACIDS (PFAAs) IN WATER ENVIRONMENT, FOOD, AND HUMAN BODY IN KLANG VALLEY, MALAYSIA / マレーシア、クラン渓谷における水環境、食品、人体中ペルフルオロアルキル酸(PFAAs)の評価

MOHD, REDZUAN BIN RAMLI 24 September 2019 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22058号 / 工博第4639号 / 新制||工||1723(附属図書館) / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 米田 稔, 教授 清水 芳久, 教授 高野 裕久 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
120

Microplastics in the Gulf of Bothnia, SwedenA comparison between Österfjärden and Örefjärden.

Overgaard, Emma January 2021 (has links)
Microplastics are emerging pollutants in the marine environment, including a range of polymers modified by varying quantities of additives and sorbed pollutants, differing in size, colour, and shape. This study focuses on characterization and quantification through visual characterization of microplastics &gt;300 μm in surface water and at 5-meter depth in the Gulf of Bothnia. A comparison between a reference area and an urban impact area was made to estimate if the water is more polluted near rural or industrial areas. The visual characterization was based on general guidelines provided by GESAMP to minimize the risks of identifying false positives. The concentrations of microplastics were found to be similar in the current study in comparison to other studies in the Baltic Sea. There was insufficient evidence to conclude a difference between the reference area and the urban impact area. A key finding in this study was that fragments, i.e. irregular shaped hard particles having appearance of being broken down from a larger piece of litter were the most abundant type of microplastics particles found. The vast majority of the identified polymers by ATR-FTIR (Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy) consisted of Polyethylene (PE) and Polystyrene (PS)

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