National Repository of Grey Literature 76 records found  beginprevious25 - 34nextend  jump to record: Search took 0.00 seconds. 
Determination of organic tin compounds in the environment
Fojt, Jakub ; Mravcová, Ludmila (referee) ; Řezáčová, Veronika (advisor)
Organotin compounds are one of the most produced and most used organometallic compounds. Some of these substances are endocrine disruptors, persistent organic polutants and their high toxic effects are observed. That’s why their presence in the environment caused by human activity could endanger many organisms. The aim of this thesis is summarize their properties and their occurrence in the environment. Then the quick, easy and relatively cheap method for determination of trialkyltin compounds in heavily poluted aquatic sediments using capillary zone electrophoresis is developed.
Preparation of water course revitalization study
ŠINDELÁŘ, Jiří
This diploma thesis deals with the design of ox-bow lake revitalization measures, located southwest to the city Strakonice. Due to its charakteristics, ox-bow lake represents high-value biodiversity area. Recently, due to a disturbation in the aquatic regime, this area is threatened in sediment issue. Practical part of the diploma thesis is focused on the sediment and water level research and monitoring of plant and animal species. Obtained data result in particular revitalization measures.
Effect of terminal electron acceptors on biogeochemical processess and phosphorus cycle in sediment
Jan, Jiří ; Borovec, Jakub ; Petráš, D. ; Osafo, Nana O. A. ; Tomková, Iva ; Hubáček, Tomáš
This study focuses on the phosphorus (P) release from sediment of inflow part of Vranov reservoir under different availability of terminal electron acceptors, mainly dissolved O2 and NO3-. To understand the cycling of P in sediments, sediment cores were incubated for five weeks in three parallel variations that simulated: i) anoxia with depleted NO3-, ii) O2 saturated water column and iii) O2 saturated water column in the presence of high concentrations of NO3-. Evaluating the release of P and the impact of Iron (Fe) and its metabolism in sediment under the different conditions, water above the sediments was monitored, porewater composition and different P fractions in the sediment were analyzed.
Anthropogenic pollutioin of the Elbe River sediments
Haismanová, Pavla ; Chalupová, Dagmar (advisor) ; Bernsteinová, Jana (referee)
The thesis focuses on contamination of sediments in fluvial lakes of the Elbe river. The research was conducted in Kluk Lake near Poděbrady which has been artificially isolated from the river and its connection to the Elbe is now limited. The thesis concentrates on chemical composition of old sediments in vertical profile which documents an old anthropogenic pollution of Elbe's floodplain. The individual layers of sediment were analyzed separately. Besides grain size, the research also determined concentration of heavy metals and arsenic (Ag, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb and Zn). The sediment samples taken near the river contained higher content of elements compared to the more distant sampling site. This finding points out to the various distribution of elements and different settling velocity in the lake. Application of the geoaccumulation index showed that the sediments were very strongly polluted by silver and moderately to strongly polluted by arsenic, cadmium, mercury, lead and zinc. Last, the sediments were unpolluted to moderately polluted by cobalt, chromium, copper, manganese and nickel. According to the methodology of the International Commission for the Protection of the Elbe River (MKOL), the concentrations of silver, mercury, nickel and lead exceeded the upper limit value. Finally,...
Stoichiometric patterns in cold oligotrophic aquatic systems
Jaroměřská, Tereza ; Žárský, Jakub (advisor) ; Vymazal, Jan (referee)
Ecological stoichiometry is a conceptual framework which helps us to describe an ecosystem through its elemental composition, fluxes of matter and balance of energy. In glacier habitats, ecological patterns are different than in the terrestrial environment, and the research has been done mostly in the last decade. The result is that stoichiometric data only exists in small amounts, and are influenced by searching area and preference of the researcher. Stoichiometry of glacial hydrological systems has patterns which are specific for these habitats, and the knowledge about invertebrate stoichiometry living in those waters is still in its early days. Powered by TCPDF (www.tcpdf.org)
The load of sediments and bentic organisms with trace metals in urban stream Botič
Hanzlíková, Lenka ; Dočkalová, Kateřina (advisor) ; Stuchlík, Evžen (referee)
Trace element bioaccumulation in benthic organisms is important part of aquatic environment pollution research, since water and sediment analysis itselfs do not provide significant information about bioavailability of contaminants and the results mostly shows just current pollution at the time of sampling. This study focuses on urban streams contamination which are currently significant source of trace elements. Botic stream was chosen as exemplary, because it is affected by many combined sewer system overflows which are sources of contamination in times of heavy rain and flood. Load several sampling took place on 10 stream sites during the year of 2012. This thesis deals with 11 trace elements concretelly Cd, Co, Cr, Cu, Hg, Ni, Zn, As, Fe, Pb and Al. Trace elements were assessed in both benthic organisms and sediment. As well taxons were selected from benthic organisms, which are widely found at any time of the reference year: caddisflies of family Hydropsychidae, leeches Erpobdella sp. and mayflies of Baetidae family. Sediment analysis included sequential extraction which divided trace elements into 4 fractions according to mobility. Based on the results, bioavailability was assessed on observed elements and correlation between concentration in bethos and sediment was tested. Finally, impact of...
Optimization of conditions for determination of bottom sediment sorption characteristics
Ramešová, Lucie ; Hanslík, Eduard (advisor) ; Pivokonský, Martin (referee)
Univerzita Karlova v Praze Lucie Ramešová Přírodovědecká fakulta Květen 2014 Ústav pro životní prostředí a VÚV T.G.M. v.v.i. OPTIMIZATION OF CONDITIONS FOR DETERMINATION OF BOTTOM SEDIMENT SORPTION CHARACTERISTICS ABSTRACT An option of this study was to optimize conditions of distribution coefficients determination in the water-sediment system. The study results will be applied in the task A research on influence of Temelín Nuclear Power Plant accident on the Vltava and Labe water environment contamination to the border profile Labe - Hřensko. After finding optimal conditions for sorption experiments, these will be applied on the experiments using real sediment samples and corresponding surface water extracted from different localities of Vltava River, Labe River respectively. A goal of the whole project is to contribute to creation of a crisis scenario of potential accident of Temelin Nuclear Power Plant and its impact on Vltava and Labe water environments. Above all, the aim is to answer the question which processes would take place in dams and basins during the contamination by fission and activation products, whether and which products would be preferably adsorbed and would consequently settle down and which would supposedly be transported to the lower parts of the watershed. The practical part of the...
Impact of urban drainage on heavy metal concentration in aquatic ecosystems
Darmovzalová, Marie ; Komínková, Dana (advisor) ; Hořická, Zuzana (referee)
Urban streams are influenced by number of human activities. Diploma thesis discusses the impact of urban drainage (specifically storm water drains) on toxic metal concentrations, of, in one of Prague's minor creeks - Zátišský Creek. Zátišský Creek flows from the right side to the Vltava River. The creek is 3080 m long with a natural flow 1.9 m3 /s. The creek is affected by seven storm water drains and three rain settling tanks. The creek was monitored from April 2009 to June 2010 during this period six sampling campaign was conducted. The samples were collected from seven remote sampling points, located both upstream and downstream from the storm water drains and rain settling tanks. The impact of storm water drains was assessed based on monitoring of toxic metals content in different parts of the aquatic environments, samples of water, sediment and aquatic biota (benthic organisms and attached algae) were collected and analyzed. The sediment samples and organisms were dried by lyophilisation (freeze dry), and digested in a microwave oven using a solution of nitric acid and hydrogen peroxide. Metal concentrations were determined by Atomic Absorption Spectrometry utilizing instrument Solaar S. Overall nine metals were identified: cadmium, lead, nickel, chromium, copper, zinc, aluminum, manganese...
Growth of aquatic vegetation in fish ponds used for recreation - Bolevecká soustava near Plzeň.
Pták, Martin ; Duras, Jindřich (advisor) ; Potužák, Jan (referee)
The aim of this diploma thesis was to clarify the differences among three different ponds (Bolevecký, Třemošenský, Šídlovský) situated in Pilsen. All of the above mentioned ponds are recreational areas where Bolevecký pond is best known for his water quality improvements since 2006 (after application of Fe and Al - colagulants and also fish - stock changes). The main difference was based on the growth of submersed water plants. The macrophytes were growing slowly or not at all in Bolevecký pond. There was a huge expansion of macrophytes (mainly Myriophyllum spicatum species) in Třemošenský and Šídlovský ponds therefore the water plants must be regulated during summer seasons by mechanical harvesting. The water in all three ponds proves the same qualities but the differences may be found in the nutrient composition of sediments. The fractionation analysis (the founders Psenner and Puczsko) confirmed the fact that all localities are poor in phosphorus however the differences were found in content of iron. The increased content of iron was observed in sediments of Šídlovksý and Třemošenský ponds (mainly in BD fraction - the iron was unstable under redox potential changes). The result of this analysis proves that phosphorus is potentially more available for macrophytes in sediments of Třemošenský and Šídlovský...

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