Determination of trace elements in the aquatic environment using diffusive gradients in thin films technique
Smolíková, V. (2022). Determination of trace elements in the aquatic environment using diffusive gradients in thin films technique. PhD Thesis. Mendel University in Brno/Vrije Universiteit Brussel: Brno. 215 pp.
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Document type: Dissertation
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| Abstract |
Water is an essential premise of life on Earthand thus the pollution of the aquatic environment nowadays receives increasing attention from researchers as well as the decision-makers and public. Besides other pollutants, monitoring of toxic metals and metalloids remain sat the centre of research interests due to their persistent and bioaccumulative nature in the environment as well as because of the need to understand their biogeochemical behaviour. The Diffusive Gradients in Thin Films (DGT) technique is a tool that can improve the knowledge about the processes that influence the bioavailability of trace elements. Thus, the main objective of this PhD study was the development and application of the DGT technique for the evaluation of selected trace elements (arsenic and uranium) in the aquatic environment. AnovelDGT resin gel utilizing the commercially available resin Lewatit FO 36 for an effective evaluation of arsenic contamination in aquatic ecosystems was developed. The technique was validated by in-situ application in the aquatic environments(e.g., water reservoir Záskalská and mineral springs Hronovka and Regnerka (Czech Republic), and Zenne River (Belgium)). The geochemistry and distribution of As species in water and sediments of the Zenne River were further investigated based on the research findings from the years 2010–2021.The combination of active and passive sampling of the water together with analysis of sediments brought new findings regarding the As pollution of the Zenne River. The DGT technique utilizing Lewatit FO 36resinwas also tested for the simultaneous determination of both elements-arsenic and uranium-that are studied in this work. For these purposes, a new elution protocol was optimized, and the technique was evaluated by in-situ application in the Scheldt estuary (Belgium). Here, an extensive comparative study investigating the influence of the salinity gradient on the performance of selected DGT techniques (utilizing Chelex-100, Dow-PIWBA, Diphonix, and Lewatit FO 36) for the determination of uranium was performed. The results demonstrated that the thorough testing of the DGT performance in a real environment and especially in complex matrices such as seawater is essential for the selection of the best DGT design for environmental applications. The results of this thesis provided a new DGT design for arsenic and uranium monitoring and at the same time brought valuable information about their geochemistry in the aquatic environment. |
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