National Repository of Grey Literature 97 records found  beginprevious21 - 30nextend  jump to record: Search took 0.00 seconds. 
Redukcia organických látok v sedimentoch za využitia bakteriálne - enzymatických zmesí
Voltemar, Erik
Accumulation of sediments in fishponds is a serious problem for today's aquaculture. High economical, organizational and time-consuming requirements are often the limit factor for many fish farmers. One of the available solutions has recently emerged bacterial-enzymatic mixtures, which thanks to modified bacteria cultures, have been able to reduce organic matter from sediment and improve overall physical and chemical water parameters. The aim of this diploma thesis was to verify the effect of the bacterial - enzymatic mixture PTP plus in laboratory and field conditions. For the laboratory experiment, was chosen a method with different concentrations of the PTP plus, under the controlled conditions of the glass containers. However, the results of the laboratory test did not confirmed significant effect of this bioenzymatic mixture on the reduction of the organic component of the sediment nor on the changes in the physical and chemical parameters of the water. But the influence at the visual properties of the water was confirmed in container with several times higher dose. Three small ponds near Bohuslavice near Konice, with a total area of approximately 2.5 hectares were chosen for the field experiment. The results of the field experiment also did not confirm the significant effect of the bio-enzymatic blend on the physical and chemical parameters of the water in the monitored localities. However, in the lowest location of the fishpond cascade, BOH I, was recorded slight reduction of sediment organic component.
The impact of eutrophication on fish in running waters
Jeníšová, Karolína ; Horká, Petra (advisor) ; Frouzová, Jaroslava (referee)
Eutrophication belongs among be the most serious factors threatening freshwater ecosystems. Eutrophication is a result of excessive nutrient loading which comes mostly from both the point-source and diffuse pollution and agriculture, increased sediment loading from soil erosion, but also due to a presence of various types of impoundments, which, particularly in some areas, represent a significat part of nutrient supply. Although the effect of eutrophication on freshwater fish communities has been thoroughly studied in standing waters, very little attention has been paid to running water ecosystems. Among the processes with the most pronounced impacts on fish communities are increased phytoplankton growth and loss of macrophytes, low oxygen levels or anoxia, occurrence of toxic forms of nitrit and ammonia and elevated turbidity and subsequent light reduction. Whilst the diversity of fish communities is not usually affected, changes in structure of fish communities and decreased ecological quality has been detected with the increasing level of eutrophication. The most sensitive fishes are salmonids as they have high oxygen demands and are very sensitive to a toxic forms of nitrogen. Moreover they are visual predators highly affected by the increased turbidity of water environment. Percids are mainly...
Sediment impact on river hydrology
Winkler, Stanislav ; Šelepa, Milan (referee) ; Marton, Daniel (advisor)
The bachelor’s thesis analyze sediments and their impact on hydrology in rivers. This thesis can be used as guide providing necessary theoretic knowledge about methods of measuring sediments and monitoring strategy. As default material have been used methodology for measurement from university BOKU Wien. Their long – standing experience and knowledge in sediment measurement sphere are inestimable and going to be used in project SEDECO – Sediments, ecosystem services and interrelation with floods and droughts in the AT – CZ border region financed through INTERREG AT – CZ.
Obnova vegetace revitalizovaného úseku řeky Stropnice
HEROVÁ, Zdenka
Three seasons of initial succession were followed in the frame of this thesis after a restoration project in a section of the Stropnice River and its floodplain. The succession tends towards formation of community of alluvial meadows, which is prevailing biotope in the neighborhood of the restored part. Strong factor influencing the course of succession is wetness of the substrate, which is partially given by distance of a site from the water-course and by the difference in the altitude of a site and of the river water table. Synantrophic species were most abundant in the first year (2014), followed by meadow and wetland species (2015, 2016).
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...

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