National Repository of Grey Literature 103 records found  beginprevious94 - 103  jump to record: Search took 0.00 seconds. 
Determination of eutrophication potential of particles in rivers and waterbody sediments
JAN, Jiří
Extraction solutions were assessed to find the most appropriate method for characterisation of particles in the context of release or uptake phosphorus in non-calcareous regions. Advantages and limitations of methods for determination of different phosphorus (P) forms and its important binding components iron and aluminium (hydr)oxides, were pointed out. Characterisations of these forms, that show highly different behaviour under changing environmental conditions, were used for the assessment of particles saturation with respect to P. Sorption/desorption behaviour of soil particles susceptible to erosion and their content of plant available P was tested. Strong correlation, which is dependent on P saturation ratio, was used to propose a method for the determination of soil erosion impact to supply dissolved P in stream waters of variable dissolved P concentration.
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.
Investigation of the sediment washing processes
Borovec, Jakub ; Jan, Jiří ; Hubáček, Tomáš
Sediment finding and the assessment of sediment amount and the characterization of sediment physico-chemical properties were performed. A methodology for the collection of large volumes of sediment samples and their subsequent washing was designed, tested, and optimized for use in the management of reservoir sediments and their further utilization. The extent of sediment contamination and its stability (phosphorus release, sediment behaviour in collection bags, the leaching of contaminants) were also determined and their influence on the reservoir functioning assessed.
Sediments of the Orlík resevoir
Borovec, Jakub ; Hejzlar, Josef ; Jan, Jiří ; Mošnerová, P.
Cílem příspěvku je shrnutí informací o vlastnostech a živinovém režimu sedimentů v podélném profilu nádrže v průběhu vegetační sezóny. Jsou ukázány rozdíly v jejich základním složení a ovlivňování vodního sloupce. Zejména je věnována pozornost rozdílu složení sedimentujících částic a sedimentu, teoretickému uvolňování živin ze sedimentů a jejich potenciálu zadržovat fosfor.
New methods for sediment description – how to their "metabolism"
Jan, Jiří ; Borovec, Jakub
Volume of reservoir sediments is usually small comparing to volume of water, but there are i) important place of nutrient recycling of water ecosystems and, ii) there are a dynamic part of the ecosystem. Large number of tightly coupled processes in the sediments is dependent on seasonal development and changes of physical, chemical and biological conditions (temperature, DO concentration, microbial activity, current conditions, amount and quality of settling material). Modern methods for nutrient balance in sediments, rates of release/uptake of nutrients and pore-water profiles were shown.

National Repository of Grey Literature : 103 records found   beginprevious94 - 103  jump to record:
See also: similar author names
10 JAN, Jiří
1 Jan, J.
2 Jan, Jaroslav
2 Ján, Jakub
2 Ján, Jan
10 Ján, Jiří
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