|
|
The content of mercury in sediments washed out from the Jordán reservoir
JAHODOVÁ, Jana
The aim of this study was to examine if the sediments were washed out from the Jordán reservoir due to the rupture of the temporary dam to the Tismenický brook and then to the Lužnice river. The aim of the work was to assess the degree of their contamination with mercury and the possible environmental risk as well. The detailed literature research focused on determination of mercury in sediments was conducted at first. Then, the characteristics of the analytical method serving for mercury determination using an AMA 254 spectrometer were calculated. After that, the contents of mercury in individual samples of sediments were determinedand the degree of the environmental contamination was evaluated. Analytical andecological aspects of this study were taken into account. The measurements were related to samples taken from eight sampling sites during the six months from November 2013 to June 2014. The sediments were taken from four depths. Localities upstream the reservoir contained very low content of mercury. Its concentration corresponded to the natural background observed in sediments (the natural occurrence of Hg in the environment). The higher concentrations of Hg were determined in samples taken from sampling sites downstream the reservoir. However,these values corresponded to the natural occurrence of this element as well. The increased mercury concentrations (1.0365 mg/kg ? 0.0398) were obtained for samples taken from the site lying close ahead of the confluence of the Tismenický brook and the Lužnice river. This value exceeded the legislative limit (regulation No. 13/1994 Sb. The higher concentrations of mercury were determined for samples taken from the Lužnice river downstream the confluence compared to samples taken upstream the confluence. It is due to the rupture of the temporary dam (in December 2012 and June 2013) that resulted in washing out the sediments from the Jordán reservoir. This ecological disaster led to the change in natural mercury occurrence in localities downstream the reservoir.
|
|
|
Effect of intensive cage fish farming on water quality in the Nechranice reservoir
Hejzlar, Josef ; Borovec, Jakub
Effect of cage fish farming on water quality in the eutrophic Nechranice reservoir was assessed through its contribution to the balance of eutrophication-effective forms of phosphorus (PO4-P) entering the reservoir and through measuring impacts on sediment around farming cages. The study showed that although the contribution of cage fish farming is relatively small (max. in tenths to a few percents of the total PO4-P load), its effect on water quality can not be neglected, because it causes direct pollution and, under certain hydrologic and climatic situations, contributes significantly to the eutrophication and to critical deterioration of water quality for recreation and bathing. On the other hand, it is indisputable that the main source of eutrophication of the Nechranice reservoir are discharges of municipal wastewater in the catchment.
|
|
|
Revitalization of ponds and biodiversity conservation - Jordán pond case study.
ŘEŽÁBEK, Pavel
The work is conceived as a literature review. Attention is devoted to a summary of basic knowledge revitalization tanks in general, focusing on removing sediment and draining the tank. The main objective is to describe the current state of the revitalization of Jordan Reservoir and problems caused by technical procedures. It also describes the biodiversity of the major groups of organisms (fish, selected groups of invertebrates and higher plants), particularly in terms of protected species under the Act. Time describes the first three years of restoration, which is currently before completion (half year to end work).
|
|
|
The influence of a control measure GAEC 2 on the sediment denuding reduction in chosen basins
HUMPÁL, David
This diploma thesis deals with the issue of sediments (undissolved substances) and with the possibilities of reducing sediment denudation in an agricultural landscape, especially my means of GAEC 2. The principal object of the thesis is to assess the effect of GAEC 2 on sediment denudation and to propose complementary erosion control measures in a landscape of interest. The research basin of the Jenínský Brook with permanent graminaceous vegetation on its soil blocks (without GAEC 2 application) and the basin of the Budský Brook in the soil blocks of which the GEAC 2 standard is applied were chosen for this thesis. The data series of concentrations of undissolved substances and flow-rates were processed to obtain the required data. The data series were gathered from themonitoring of collection cross-sections J1, J2 (Jenínský Brook micro - basin) and collection cross-section B1 (Budský Brook micro - basin) in the hydrological years 2011 and 2012. The results obtained were compared and the causes of the resulting values including the GAEC 2 effect were established. Appropriate measures to be taken to reduce sediment denudation were proposed based on the detailed research of the basins in question.
|
|
| |
|
|
Influence of common sources of communal pollution on aquatic environments
ŠATRA, Václav
The aim of the thesis was to assess the impact of current sources of sewage treatment plant (STP) located upstream on the contamination of the aquatic environment. In 2009 contamination assessment was carried out at three selected sites located within the municipal sewage treatment plant and at three sites located above these potential sources of pollution. Brown trout (Salmo trutta m.fario L.) was the indicated species. The presence of MUSK materials , brominated flame retardants (BFRs) and organochlorinated persistent pollutants (POPs) was being detected within the selected samples of fish muscles and sediments.
|
|
|
Manipulation with flow rates in water bodies - the possibilities for inhibition of cyanobacterial blooms development
Maršálek, Blahoslav ; Šejnohová, Lenka ; Vinklárková, Darina ; Plotěný, Miroslav ; Jančula, Daniel
If we compare the sediment capping by active barriers to protect the phosphorus release from sediments with other technologies of manipulation with methods of water discharge, it is clear, that by well-considered manipulations with water discharge, it is possible to reach the same (comparable) results with lower costs and with lower ecotoxicological and limnological risks. By the manipulation of water level, it is possible to reduce cyanobacterial bloom development as supplemental or supporting measure, but the effects may differ in different water bodies and thus it must be consulted always with specialists.
|
|
|
The effect of delimitation of land on the reduction of sediment transport
HUMPÁL, David
This Bachelor´s Thesis deals with sediment denuding and with its possible reduction in the agricultural landscape by means of delimitation and other erosion control measures. The introductory part is devoted to general characteristics of the sediment, and indicates the amount of sediment in each element of hydrological network in the Czech Republic and in the world. The following two parts describe causes and consequences of higher concentration of sediment in the water environment. Factors affecting sediment denuding into surface waters and the description of these factors are determined in the following part. The last two parts, which are the most comprehensive, deal with means serving to reduction of sediment denuding in the agricultural landscape in term of erosion protection, and possibilities of delimitation application to limit sediment denuding. The aim of this work is to identify and describe protective measures, especially delimitation measures, which are used to reduce sediment denuding in the agricultural landscape, while pointing out the consequences that are caused by sediment in the water environment, coming mainly from poorly protected farmland.
|
|
|
Indirect speciation of mercury in soils and sediments with cold vapor atomic absorption spectrometry.
ŠPAČKOVÁ, Jitka
In the diploma thesis have been tested four extraction techniques for isolation of organic forms of mercury from sediments (liquid liquid extraction, microwave extraction in liquid liquid extraction, solid phase extraction and extraction with use of ionic exchange) followed by determination of mercury by atomic absorption spectrometer AMA?254. It has been achieved great results during liquid liquid extraction likewise ionic exchange extraction. Reached percents of orgHg were in accord with certified reference material for sediments CRM-580 and corresponded to 86,44 ? 16,63 %, resp. 87,01 ? 29,22 %. Thanks to a simple procedure, extraction speed and ease of determination of organic forms of mercury contain was first of all (in the first instance) verified a method with use of ionic exchange, whose principle and procedure is very elementary. This technique was applied to a number of real sediment samples collected from water tanks Jordan and Skalka. It was approved that this method has been presenting a suitable alternative to chromatographic methods or methods of electro?migration.
|
|
|
Study of properties DET, a method for pore water for sediment sampling
JAROLÍMOVÁ, Zuzana
The aim of this thesis was find out chosen properties of DET (diffusive equilibration in thin films), method for pore water for sediment sampling. This properties were: 1)the time require for equilibration between: a)distilled water in gel within DET and pore water b)sample of pore water within DET and distilled water 2)the comparison of samples pore water sampling with DET and other method 3)determination of DET properties in practice
|
guest ::
