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Soil solution - supramolecular architecture and stability of dissolved organic matter
Trubková, Eliška ; Doskočil, Leoš (referee) ; Enev, Vojtěch (advisor)
This final thesis is focused on the complex physico-chemical characterization of soil solutions, especially with a focus on the study of the stability and molecular architecture of dissolved organic matter. The subject of the study was six soil solutions obtained from lysimeters in the Závišín locality. Three soil solution samples were taken in December 2022 and the remaining three samples were taken one month later in January 2023, at horizons at 40, 60 and 80 cm below the soil surface. Characterization of soil solutions included measurements of their pH and conductivity. Mass and optical emission spectrometry with inductively coupled plasma was used to determine the concentration of cations. The determination of the total dissolved organic matter content was carried out according to the technical standard ČSN 75 7536 and the values of absorption coefficients were calculated using UV/Vis spectrometry. Functional groups and basic structures of soil solutions were identified based on the evaluated spectra from infrared spectrometry with Fourier transformation. The main contribution was fluorescence spectrometry, which was used to determine the fluorescence intensities of A–fulvic-like and C–humic-like fluorophores. Particle size was also measured using dynamic light scattering and zeta potential, which was a suitable indicator of the stability of selected soil solution samples. The obtained results very well characterized both individual soil solutions and dissolved organic matter.
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Development of Gel Techniques for in situ Measurement of Bioavailable Metals in Soils and Sediments
Kovaříková, Vladěna ; Sommer, Lumír (referee) ; Janoš, Pavel (referee) ; Dočekalová, Hana (advisor)
The doctoral thesis deals with usage of gel techniques for in situ measurement of bioavailable metals in soils and sediments. The DGT technique was applied to soil samples from the localities of Zlín, Tuřany and Chrlice for estimation of bioavailable metals in soils. These soils were amended by sewage sludges in years 1980-1987. The experiment using diffusive gels with different pore size, APA and RG gels, has shown that the DGT can be used for assessment of trace metal soil complexes - small inorganic and larger organic. The results obtained by DGT measurements were approximately up to two orders of magnitude lower than metal concentrations obtained by leaching with sodium nitrate. The leaching with sodium nitrate does not provide true reflection of metal availability to plant root system and soil microorganisms and the DGT technique seems to be a better predictor of metal bioavailability. Only small differences between undisturbed and homogenized soil samples were found out by application of DGT to soil samples from localities of Veverská Bítýška and Ostrovačice. The undisturbed soil is not homogenous and the DGT unit gives information only about the part of the soil which is in direct contact with the unit. The procedure with soil slurry can be recommended for the characterization of large soil areas and estimation of bioavailable metals in soils. Gel techniques were also used for the study of processes occuring in sediments. Mercury species and other metals were analysed in surface water, pore water and sediments collected from two sampling sites in the Dele River in northern France. This river had been polluted during the last century by the activity of Métaleurop factory, which dealt with metal ore treatment. The application of DGT technique using two specific ion-exchange resins, Chelex-100 and Duolite GT-73, provided assessment of mercury in sediment pore water. DGT and DET techniques together with centrifugation provided also high resolution depth profiles of Fe, Mn, Zn, Pb, Cr and Cd in pore water. It is not possible to determine which sampling site was more contaminated. Only small differences in mercury species and metal content were observed between sampling sites. The Dele River can be classified as contaminated river according to total mercury content in sediments and as slightly contaminated river from the point of view of methylmercury content. Correlations between mercury species and sulphide content confirm that total mercury and sulphide content count among factors influencing the mercury release to pore water and controlling processes of methylation and demethylation. Only low toxicity of sediment slurries was found out by the bioluminiscence test with Vibrio fischeri. The results of doctoral thesis demonstrate gel techniques as a very good tool in environmental analysis.
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Dynamics of dissolved organic matter depending on the activity of ants in coniferous temperate forest
Vacířová, Anna ; Jandová, Kateřina (advisor) ; Cepáková, Šárka (referee)
5 Abstrakt Soil organic matter is the largest reservoir of carbon in terrestrial ecosystems, and its functionally important component is dissolved organic matter. Its composition and changes in this composition during the vegetation season affect the vegetation, the activity of the organisms in the soil and the formation of soil organic matter. Local bio-hotspots such as anthills create spatial heterogeneity of the soil solution composition. In my work I analyzed cold water (CWE) and hot water (HWE) soil extracts, which I took in different distances from the anthill, in three soil horizons (O, A, B) three times during one vegetation season. I measured contents of carbon (C), nitrogen (N), C: N ratio and the parameter SUVA254 and SUVA280. The labile C and N content varied with the distance from the anthill. The C and N content with the distance from the anthill at O horizon increases, decreases in A and B. C: N ratio was the highest in the A horizon, but during the season the differences were not so significant. The smallest content of C and N was in April, the highest in July. The SUVA parameter in O and B decreases with distance from anthill, in A on the other hand it has risen. Ants have an effect not only on the quantity but also on the quality of the DOM, at the same time creating heterogeneity of DOM...
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Dynamics of dissolved organic matter depending on the activity of ants in coniferous temperate forest
Vacířová, Anna ; Jandová, Kateřina (advisor) ; Cepáková, Šárka (referee)
5 Abstrakt Soil organic matter is the largest reservoir of carbon in terrestrial ecosystems, and its functionally important component is dissolved organic matter. Its composition and changes in this composition during the vegetation season affect the vegetation, the activity of the organisms in the soil and the formation of soil organic matter. Local bio-hotspots such as anthills create spatial heterogeneity of the soil solution composition. In my work I analyzed cold water (CWE) and hot water (HWE) soil extracts, which I took in different distances from the anthill, in three soil horizons (O, A, B) three times during one vegetation season. I measured contents of carbon (C), nitrogen (N), C: N ratio and the parameter SUVA254 and SUVA280. The labile C and N content varied with the distance from the anthill. The C and N content with the distance from the anthill at O horizon increases, decreases in A and B. C: N ratio was the highest in the A horizon, but during the season the differences were not so significant. The smallest content of C and N was in April, the highest in July. The SUVA parameter in O and B decreases with distance from anthill, in A on the other hand it has risen. Ants have an effect not only on the quantity but also on the quality of the DOM, at the same time creating heterogeneity of DOM...
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Development of Gel Techniques for in situ Measurement of Bioavailable Metals in Soils and Sediments
Kovaříková, Vladěna ; Sommer, Lumír (referee) ; Janoš, Pavel (referee) ; Dočekalová, Hana (advisor)
The doctoral thesis deals with usage of gel techniques for in situ measurement of bioavailable metals in soils and sediments. The DGT technique was applied to soil samples from the localities of Zlín, Tuřany and Chrlice for estimation of bioavailable metals in soils. These soils were amended by sewage sludges in years 1980-1987. The experiment using diffusive gels with different pore size, APA and RG gels, has shown that the DGT can be used for assessment of trace metal soil complexes - small inorganic and larger organic. The results obtained by DGT measurements were approximately up to two orders of magnitude lower than metal concentrations obtained by leaching with sodium nitrate. The leaching with sodium nitrate does not provide true reflection of metal availability to plant root system and soil microorganisms and the DGT technique seems to be a better predictor of metal bioavailability. Only small differences between undisturbed and homogenized soil samples were found out by application of DGT to soil samples from localities of Veverská Bítýška and Ostrovačice. The undisturbed soil is not homogenous and the DGT unit gives information only about the part of the soil which is in direct contact with the unit. The procedure with soil slurry can be recommended for the characterization of large soil areas and estimation of bioavailable metals in soils. Gel techniques were also used for the study of processes occuring in sediments. Mercury species and other metals were analysed in surface water, pore water and sediments collected from two sampling sites in the Dele River in northern France. This river had been polluted during the last century by the activity of Métaleurop factory, which dealt with metal ore treatment. The application of DGT technique using two specific ion-exchange resins, Chelex-100 and Duolite GT-73, provided assessment of mercury in sediment pore water. DGT and DET techniques together with centrifugation provided also high resolution depth profiles of Fe, Mn, Zn, Pb, Cr and Cd in pore water. It is not possible to determine which sampling site was more contaminated. Only small differences in mercury species and metal content were observed between sampling sites. The Dele River can be classified as contaminated river according to total mercury content in sediments and as slightly contaminated river from the point of view of methylmercury content. Correlations between mercury species and sulphide content confirm that total mercury and sulphide content count among factors influencing the mercury release to pore water and controlling processes of methylation and demethylation. Only low toxicity of sediment slurries was found out by the bioluminiscence test with Vibrio fischeri. The results of doctoral thesis demonstrate gel techniques as a very good tool in environmental analysis.
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The innovation of methods to control phosphorus status of agricultural soils from consensus of agricultural and environmental apsects of frugal using natural resources
Matula, Jiří
Methodology solves efficient phosphorus supply levels of agricultural soils from agricultural and environmental consensus trough recognition of maximum and minimal concentration of soluble phosphorus fraction in soil solution which is really needed to keep reasonable crop production of agricultural fields. The limitation and do not crossing of necessary maximum P-concentration in soil solution also helps to minimize possible P-losses by surface runoff and subsurface flow. The basic step of solution is standardized laboratory technique extraction of soil solution from soil sample including also the terminal-analytical P determination. And then the estimation range of convenient P concentration in soil solution. The last step is regression between multi-nutrient soil tests (water extraction, ammonium acetate extraction with addition ammonium fluoride and Mehlich 3 soil test) and P-concentration in soil solution. In the case of close regression is then used for recalibration soil tests from agricultural-environmental consensus.
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