Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 16 of 16 for “"sediment chemistry"”.
-
Modelling water and sediment chemistry in urban canals using chironomid pupal exuviae
… to classify canals in terms of water and sediment chemistry. The fourth was to analyze potential boundaries between Water Framework Directive (WFD) classes and develop a method to calculate ecological quality ratios that will support the objectives of the WFD. Calibrated chironomid-based …
-
Sediment chemistry as an archive of provenance and weathering in the Mekong River Basin
… oxyhydroxide pool. In conjunction with the river sediments, new data on major elements and lithium isotopes in the dissolved load and from a sediment core of Tonle Sap, a lake connected to the Mekong, are also presented for comparison. The major conclusions from these data are: 1) The exchangeable …
-
THE IMPORTANCE OF PHYSICAL MIXING AND SEDIMENT CHEMISTRY IN MERCURY AND METHYLMERCURY BIOGEOCHEMICAL CYCLING AND BIOACCUMULATION WITHIN SHALLOW ESTUARIES
… mesocosm experiments, the long-term effects of sediment resuspension on the fate, transport, and bioaccumulation of Hg and MeHg in shallow ecosystems. A bioenergetic-based model including sediment resuspension was developed to assess MeHg bioaccumulation into benthic and pelagic organisms under …
-
The Paleolimnology of Irondequoit Bay: Trophic History Inferred from Sedimentary Diatom Assemblages
… include diatom analysis, radiometric dating and sediment chemistry. Using these three tests the author was able to determine the condition of diatoms, the time period tested, and the water quality respectively. The research suggests that the diversity of diatoms found within the bay coincide with …
-
Mineralogy, Chemistry & Flux of Suspended Sediments in Himalayan Rivers
The flux and composition of river suspended sediments contain valuable information on processes including erosion rates, the composition of the eroded bed rocks, chemical weathering and sediment storage and sorting within river channels. In this thesis, samples from the Kosi River in Nepal (a major …
-
Improving the applicability of metabarcoding to monitor salmon farming impacts on benthic environments
… the seabed (benthic environment) which affects sediment chemistry and fauna. The current method of impact monitoring, through morphological identification of macrofauna, is time-consuming and expensive. These limitations can be overcome with environmental DNA (eDNA) metabarcoding. To utilise …
-
The geochemistry of groundwater and sediments governing tungsten concentration in the basin-fill aquifers, Fallon, Nevada
… the mineralogical phase association(s) of W in sediments of the basin-fill alluvial aquifer near Fallon, NV, were identified in this study. These sediment characteristics were then compared to groundwater concentrations of W in an attempt to understand the geochemical controls on W in the …
-
Effects of drift macroalgae on sediment nitrogen cycling in Thalassia testudinum beds of St. Joseph Bay, FL
… in N cycling pathways because they can alter sediment chemistry. Previous research has associated drift macroalgae blooms with elevated dissolved inorganic N concentrations in sediments as a result of increased remineralization of organic matter, but drift macroalgae effects on microbial N …
-
The Fate and Mobility of Heavy Metals in East Anglian Salt Marsh Sediments
… in Earth Sciences. Geochemical proxies in sedimentary rocks used to reconstruct past redox conditions—such as the speciation of iron mineralogy, δ98Mo, and δ53Cr—rely on the assumption that the geochemical signature acquired at the sediment surface is translated directly into the geologic …
-
Ecotoxicological Evaluation of Hollow Fill Drainages in Low Order Streams in the Appalachian Mountains of Virginia and West Virginia
… of hollow fill drainages included water/sediment chemistry, acute water column toxicity testing using <i>Ceriodaphnia dubia</i>, chronic sediment toxicity testing using <i>Daphnia magna</i>, benthic macroinvertebrate surveys, and <i>in situ</i> Asian clam (<i>Corbicula fluminea</i>) …
-
Investigating the cause(s) of benthic macroinvertebrate community impairment downstream of two Saskatchewan uranium operations
… using a weight-of-evidence approach. Given that sediments generally accumulate contaminants that are related to metal mining activities (such as metals and radionuclides), the initial hypothesis for this research was that contaminated sediments were the primary cause of benthic community …
-
Evaluation of approaches for the derivation of defensible sediment quality guidelines for application at Saskatchewan uranium operations
Sediment quality guidelines (SQGs) or values (SQVs) are used to assess the potential risk of contaminants in sediment to aquatic organisms, specifically benthic invertebrates. The objectives of this research were to evaluate SQGs derived specifically for use by the uranium industry in Canada, …
-
Silicate weathering in the Himalayas: Constraints from the Li isotopic composition of river systems
… with cations, thereby controlling both seawater chemistry and climate. The rate of CO2 consumption is closely linked to the rate of CO2 outgassing from the planetary interior, providing a negative feedback loop essential to maintaining an equable climate on Earth. Reconstruction of past global …
-
The influence of sediment nutrient dynamics on the response of lake ecosystems to restoration and climate change
… nutrient loads, phytoplankton abundance and chemistry. However, little is known about the potential effects of future climate change on lake water quality. Understanding the dynamics, abundance and availability of nutrient pools in lake bottom sediments is fundamentally important for …
-
Sedimentary lipids as indicators of depositional conditions in the coastal Peruvian upwelling regime
This thesis assesses the utility of various sedimentary lipids as indicators of short-term changes in depositional conditions and sedimentary organic matter sources in the coastal upwelling regime off of Peru. A variety of lipids (n-alkanes, n-alkanols, C37 alkenones, hopanoids, keto-ols, lycopane, …
-
Impacts of artisanal and large scale gold mining on tropical rivers in West Africa: A case study from the Brong Ahafo Region of Ghana
… LSM impacted the respective river’s water and sediment quality, macroinvertebrate and microbial (Archaea and Bacteria) community structures and resulted in mercury biomagnification in fish. ASGM impact on river water and sediment quality was determined using a reversed BACI (Before/After and …