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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.
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Methodology for identification and quantification of sediments in water reservoirs
Borovec, Jakub ; Jan, Jiří ; Vrzák, J. ; Knotek, J.
The study was designed to find methodical procedures for effective and accurate detection and quantification of bottom sediments in water reservoirs, including an assessment of their impact on the quality of water in the reservoirs. The study summarizes the overall problem of sediments in the water bodies. Advantages and disadvantages of methods and equipment widely used for sediment sampling procedures for their quantification are assessed. The result is a developed optimal methodical procedure for proper spatial localization of sediments and determination of their volumes in given zones. The methodology also includes a precise procedure for the evaluation of its chemical parameters and the P cycle with further determination of the sediment potential to deteriorate water quality in the reservoirs.
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A new tool for improvement the quality of water ecosystems
Blabolil, Petr ; Říha, Milan ; Peterka, Jiří ; Prchalová, Marie ; Vašek, Mojmír ; Frouzová, Jaroslava ; Jůza, Tomáš ; Muška, Milan ; Tušer, Michal ; Draštík, Vladislav ; Ricard, Daniel ; Sajdlová, Zuzana ; Šmejkal, Marek ; Vejřík, Lukáš ; Matěna, Josef ; Borovec, Jakub ; Kubečka, Jan
The Czech multimetric fish based index (CZ-FBI) was developed recently. The aim of CZ-FBI is to assess the ecological potential of heavily modified and artificial water bodies and to detect ecosystems, particularly their specific components, in unsatisfactory conditions. This article describes steps of CZ-FBI development. Since the philosophy used, particular events presenting the results, to recent stage. CZ-FBI is a part of certified methodology of the Ministry of the Environment of the Czech Republic and the comparison with other assessment methodologies within a geographical intercalibration group is in process.
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Erosion of agricultural land and its importance for siltation and eutrophication of reservoirs in the Czech Republic
Krása, J. ; Jáchymová, B. ; Bauer, M. ; Dostál, T. ; Rosendorf, P. ; Hejzlar, Josef ; Borovec, Jakub ; Bečička, M.
In 58 large catchments of the Czech Republic (covering ca 35000 km2) the sediment transport processes were assessed. Amount of sediment flux into the streams and reservoirs from agricultural land was estimated. Sediment retention in all reservoirs was considered based on reservoirs‘ outflow. For thousands of small ponds the volumes and outflow had to be estimated based on reservoir areas and specific flow rates in catchments. The distributed approach allowed considering importance of particular agricultural fields for stream silting. The maps of annual sediment flow in all streams were derived. The sediment fluxes cause serious problems not only concerning eutrophication. For example Vltava river watershed up to Slapy dam (12 965 km2) exports 2.34 million tons of sediment by water erosion annually. 626 thousand ton is exported into the streams, and 615 500 t is then deposited in the reservoirs.
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Management of reservoir sediments, sediment washing and reuse
Vrzák, J. ; Knotek, J. ; Borovec, Jakub ; Dadejík, M. ; Krist, P.
This article is primarily intended to introduce to the expert public, especially the operators of waterworks, the new procedures for the management of sediments in water reservoirs. These include the identification of sediments, their localization, extraction, and transformation, as well as options for the sediment washing and their possible subsequent use. Presented techniques aim to find an economically feasible management solution for reservoirs affected by deteriorated water quality - cyanobacteria./nIn the years 2012 – 2014, a research project entitled “VVIF/nResearch of washing processes in dam sediments” has been conducted. One of the objectives of the project was to find suitable methods for locating the dam sediment, sampling and identification of its material composition, which is an essential prerequisite for the selection of environmentally friendly and economically efficient processes and procedures, from preparation/nto implementation of the project. Another of the key objectives was the design and test of the process of sediment washing into primary components, with/nthe option of their reuse, or the transformation process of the whole sediment inside or outside of the reservoir.
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What can we say about sediments, evaluation of reservoir sediments and their link to eutrophication
Jan, Jiří ; Borovec, Jakub ; Hubáček, Tomáš
This work is focused on a detailed sediment evaluation and potential sediment impact on the eutrophication of reservoirs. Two methods for this purpose are presented: i) fractionation for sediment particles characterization and ii) an application of gel minipeepers (DET probes) for sediment pore water sampling. By combining these methods we are able to determine the potential of P release from selected sediment. Examples of using/nthis approach on various sediment types are given to highlight the importance of determining not only the concentrations of total P in the sediment, but also, especially, the following: i) P concentrations in different forms, ii) concentrations of main binding partners for P in noncalcareous sediments – Fe and Al (hydr)oxides, iii) concentrations of dissolved P and Fe in sediment pore water, iv) concentrations of ions influencing redox/nconditions (NO3-) both in the water above the sediment and especially in the sediment pore water.
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Influence of cage fish farming on water quality in the eutrophic Nechranice Reservoir
Hejzlar, Josef ; Borovec, Jakub ; Zahrádka, V. ; Rosendorf, P.
Influence 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 Nechranice Reservoir are discharges of municipal wastewater in the catchment.
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