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Production, Characterization and Design of Applications of Regenerated Humic Acids
David, Jan ; Grasset, Laurent (oponent) ; Taraba, Boleslav (oponent) ; Novotná, Miroslava (oponent) ; Kučerík, Jiří (vedoucí práce)
Submitted thesis deals with the humic substances, namely the humic acids and their salts, i.e. potassium humates. A literature review about humic substances is presented, the brief history of their research, their structure issues, supramolecular arrangement and applications. A special attempt is paid to review methods of extractions of humic acids from various sources. Further, the papers concerning biological, hormone-like properties are listed and discussed. From the environmental chemistry point of view mainly sorption properties are overviewed. Industrial applications of humics are covered by a wide range of patents and published works such as for instance dyes, polymer additives, etc. In experimental part, the regeneration of lignite and preparation of humic acids and their salts is described. The regeneration principle lies in the oxidation of parental lignite with a range of concentrations of nitric acid and hydrogen peroxide. Novel approach is presented in the characterization humic substances, where the chemical characteristics like Elemental Analysis, Fourier Transform Infra-red Spectroscopy and Thermogravimetry are followed by physico-chemical assessments (Dynamic Light Scattering, Fast Field Cycling Nuclear Magnetic Resonance Relaxometry, High Performace Size Exclusion Chromatography and Fluorescence Spectroscopy in combination with research of humates hydration by means of High Resolution Ultrasonic Spectrometry and Densitometry). These chemical and physico-chemical characteristics are put into the correlation with the biological characteristics, i.e. biological activity of humates, which is assessed by a slightly modified method based on the determination of maize roots weight, length and number of lateral roots. Finally, the statistical approach is applied via Pearson’s correlation coefficient and as a pilot studies, two environmental applications of regenerated humic materials are designed, in the field of sorption of tetracycline antimicrobial and researching of regenerated lignited as a potential source of fermentable sugars.
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Molecular study of lipids in humic acids by sequential chemical degradation
Bachratá, Radka ; Grasset, Laurent (oponent) ; Klučáková, Martina (vedoucí práce)
Soil lipids were shown to have relatively high resistance to biodegradation and therefore could provide information on organic matter sources and diagenetic processes. Soil organic matter is highly heterogeneous and different dynamic pools have been evidenced. However the links between these pools and molecular structure have not yet been established. Lipid and bitumen analyses were performed for two samples (i.e. peat and lignite). Numerous compound classes (free hydrocarbons and free ketones, bound alkanols, bound fatty acids, bound -hydroxy acid, bound diacids and polycyclic compounds) were identified in both samples and their different distribution was determined. GC/MS analysis of the free and bound lipids has revealed different main sources depending on the differential degradation. Some similarities could be a strong sign of the preservation of a part of waxes and suberins from higher plants (long chained bound fatty acids.) Large differences in lipid molecular composition were observed between the samples, illustrating the importance of studying lipids from a young sediment (peat) and an older one (lignite).
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Production, Characterization and Design of Applications of Regenerated Humic Acids
David, Jan ; Grasset, Laurent (oponent) ; Taraba, Boleslav (oponent) ; Novotná, Miroslava (oponent) ; Kučerík, Jiří (vedoucí práce)
Submitted thesis deals with the humic substances, namely the humic acids and their salts, i.e. potassium humates. A literature review about humic substances is presented, the brief history of their research, their structure issues, supramolecular arrangement and applications. A special attempt is paid to review methods of extractions of humic acids from various sources. Further, the papers concerning biological, hormone-like properties are listed and discussed. From the environmental chemistry point of view mainly sorption properties are overviewed. Industrial applications of humics are covered by a wide range of patents and published works such as for instance dyes, polymer additives, etc. In experimental part, the regeneration of lignite and preparation of humic acids and their salts is described. The regeneration principle lies in the oxidation of parental lignite with a range of concentrations of nitric acid and hydrogen peroxide. Novel approach is presented in the characterization humic substances, where the chemical characteristics like Elemental Analysis, Fourier Transform Infra-red Spectroscopy and Thermogravimetry are followed by physico-chemical assessments (Dynamic Light Scattering, Fast Field Cycling Nuclear Magnetic Resonance Relaxometry, High Performace Size Exclusion Chromatography and Fluorescence Spectroscopy in combination with research of humates hydration by means of High Resolution Ultrasonic Spectrometry and Densitometry). These chemical and physico-chemical characteristics are put into the correlation with the biological characteristics, i.e. biological activity of humates, which is assessed by a slightly modified method based on the determination of maize roots weight, length and number of lateral roots. Finally, the statistical approach is applied via Pearson’s correlation coefficient and as a pilot studies, two environmental applications of regenerated humic materials are designed, in the field of sorption of tetracycline antimicrobial and researching of regenerated lignited as a potential source of fermentable sugars.
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Molecular study of lipids in humic acids by sequential chemical degradation
Bachratá, Radka ; Grasset, Laurent (oponent) ; Klučáková, Martina (vedoucí práce)
Soil lipids were shown to have relatively high resistance to biodegradation and therefore could provide information on organic matter sources and diagenetic processes. Soil organic matter is highly heterogeneous and different dynamic pools have been evidenced. However the links between these pools and molecular structure have not yet been established. Lipid and bitumen analyses were performed for two samples (i.e. peat and lignite). Numerous compound classes (free hydrocarbons and free ketones, bound alkanols, bound fatty acids, bound -hydroxy acid, bound diacids and polycyclic compounds) were identified in both samples and their different distribution was determined. GC/MS analysis of the free and bound lipids has revealed different main sources depending on the differential degradation. Some similarities could be a strong sign of the preservation of a part of waxes and suberins from higher plants (long chained bound fatty acids.) Large differences in lipid molecular composition were observed between the samples, illustrating the importance of studying lipids from a young sediment (peat) and an older one (lignite).
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