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Stability of amorphous Mn oxide-based sorbent as a function of pH
Tomášová, Zdeňka ; Ettler, Vojtěch (advisor) ; Vítková, Martina (referee)
Soil systems contaminated by toxic metals and metalloids from anthropogenic sources present hazard for human health and other environmental compartments. Chemical stabilization using the Fe, Al and Mn oxides is one of the potential decontamination techniques. Manganese oxides exhibit a number of properties for being efficient sorbents of toxic metals, such as low point of zero charge, structure that allows ion acceptance and large specific surface. The focus of this thesis is to determine the stability of novel synthetic amorphous manganese oxide (AMO) as a function of pH using the pH-static leaching test. Manganese was released into the solution, with decreasing concentration in leachate as a function of pH: Mn concentration at pH 3 was 34 100 mg/L and at pH 8 only 90 mg/L. The data show that the solid phase mass loss is clearly dependent on the pH value, with the mass loss of 98,4 % and 11,2 % at pH 3 and 8, respectively. On the AMO surfaces, the newly formed crystals of rodochrosite (MnCO3) were observed; they partly control the Mn release at pH > 5. Based on the observed pH-dependent stability, it appears that the use of AMO as a sorbent of toxic metals could be a suitable method for neutral or alkaline soils, while its application for acidic soils seems to be unsuitable. Powered by TCPDF (www.tcpdf.org)
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Efficiency of chemical stabilization of a contaminated soil using amorphous manganese oxide
Tomášová, Zdeňka
Soil contamination by toxic metals and metalloids is currently one of the most discussed topics in the environmental sciences. Chemical stabilization of contaminated soils using amendments such as Fe, Mn and Al oxides belongs to one of the in situ remediation methods. Manganese oxides are naturally present in soils and they exhibit a number of properties for being efficient sorbents of toxic metal(loid)s, such as a low point of zero charge, a large specific surface and a structure that allows ion acceptance. The focus of this thesis is to determine efficiency of chemical stabilization of a smelter-contaminated soil using the amorphous manganese oxide (AMO) under various pH conditions. The agricultural soil polluted by emission from a Pb smelter (located in Příbram, Czech Republic; Pb 1 100 mg/kg, Zn 294 mg/kg, Cd 4.98 mg/kg, As 118 mg/kg and Sb 48.9 mg/kg) was amended with the AMO and incubated for 2 and 6 months. The soil was subsequently subjected to a pH-static leaching procedure in the pH range of 3-8. The presence of AMO in soil increased the soil natural pH from 5.77 to 6.59 and 6.23 after 2 and 6 months, respectively. The pH-static experiments indicated that no effect of the AMO treatment was observed for Cd and Zn, whereas the leaching of other contaminants (As, Cu, Pb, Sb) decreased...
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Efficiency of chemical stabilization of a contaminated soil using amorphous manganese oxide
Tomášová, Zdeňka
Soil contamination by toxic metals and metalloids is currently one of the most discussed topics in the environmental sciences. Chemical stabilization of contaminated soils using amendments such as Fe, Mn and Al oxides belongs to one of the in situ remediation methods. Manganese oxides are naturally present in soils and they exhibit a number of properties for being efficient sorbents of toxic metal(loid)s, such as a low point of zero charge, a large specific surface and a structure that allows ion acceptance. The focus of this thesis is to determine efficiency of chemical stabilization of a smelter-contaminated soil using the amorphous manganese oxide (AMO) under various pH conditions. The agricultural soil polluted by emission from a Pb smelter (located in Příbram, Czech Republic; Pb 1 100 mg/kg, Zn 294 mg/kg, Cd 4.98 mg/kg, As 118 mg/kg and Sb 48.9 mg/kg) was amended with the AMO and incubated for 2 and 6 months. The soil was subsequently subjected to a pH-static leaching procedure in the pH range of 3-8. The presence of AMO in soil increased the soil natural pH from 5.77 to 6.59 and 6.23 after 2 and 6 months, respectively. The pH-static experiments indicated that no effect of the AMO treatment was observed for Cd and Zn, whereas the leaching of other contaminants (As, Cu, Pb, Sb) decreased...
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Efficiency of chemical stabilization of a contaminated soil using amorphous manganese oxide
Tomášová, Zdeňka ; Ettler, Vojtěch (advisor) ; Trakal, Lukáš (referee)
Soil contamination by toxic metals and metalloids is currently one of the most discussed topics in the environmental sciences. Chemical stabilization of contaminated soils using amendments such as Fe, Mn and Al oxides belongs to one of the in situ remediation methods. Manganese oxides are naturally present in soils and they exhibit a number of properties for being efficient sorbents of toxic metal(loid)s, such as a low point of zero charge, a large specific surface and a structure that allows ion acceptance. The focus of this thesis is to determine efficiency of chemical stabilization of a smelter-contaminated soil using the amorphous manganese oxide (AMO) under various pH conditions. The agricultural soil polluted by emission from a Pb smelter (located in Příbram, Czech Republic; Pb 1 100 mg/kg, Zn 294 mg/kg, Cd 4.98 mg/kg, As 118 mg/kg and Sb 48.9 mg/kg) was amended with the AMO and incubated for 2 and 6 months. The soil was subsequently subjected to a pH-static leaching procedure in the pH range of 3-8. The presence of AMO in soil increased the soil natural pH from 5.77 to 6.59 and 6.23 after 2 and 6 months, respectively. The pH-static experiments indicated that no effect of the AMO treatment was observed for Cd and Zn, whereas the leaching of other contaminants (As, Cu, Pb, Sb) decreased...
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Stability of amorphous Mn oxide-based sorbent as a function of pH
Tomášová, Zdeňka ; Ettler, Vojtěch (advisor) ; Vítková, Martina (referee)
Soil systems contaminated by toxic metals and metalloids from anthropogenic sources present hazard for human health and other environmental compartments. Chemical stabilization using the Fe, Al and Mn oxides is one of the potential decontamination techniques. Manganese oxides exhibit a number of properties for being efficient sorbents of toxic metals, such as low point of zero charge, structure that allows ion acceptance and large specific surface. The focus of this thesis is to determine the stability of novel synthetic amorphous manganese oxide (AMO) as a function of pH using the pH-static leaching test. Manganese was released into the solution, with decreasing concentration in leachate as a function of pH: Mn concentration at pH 3 was 34 100 mg/L and at pH 8 only 90 mg/L. The data show that the solid phase mass loss is clearly dependent on the pH value, with the mass loss of 98,4 % and 11,2 % at pH 3 and 8, respectively. On the AMO surfaces, the newly formed crystals of rodochrosite (MnCO3) were observed; they partly control the Mn release at pH > 5. Based on the observed pH-dependent stability, it appears that the use of AMO as a sorbent of toxic metals could be a suitable method for neutral or alkaline soils, while its application for acidic soils seems to be unsuitable. Powered by TCPDF (www.tcpdf.org)
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Základní registry veřejné správy, problémy veřejných rejstříků
Vašák, Michal ; Rieger, Pavel (advisor) ; Tomášová, Zdeňka (referee)
Práce si dává za cíl přiblížit problematiku veřejných registrů, databází, seznamů, informačních systémů (dále jen "registry") ve veřejné správě. Uvádí demonstrativní výčet registrů, které jsou zakotveny v právním řádu ČR, a jejichž užívání platná právní úprava upravuje. Vymezeny a popsány jsou registry veřejné správy, orgány veřejné správy, které tyto registry spravují a způsob nakládání s informacemi z těchto registrů. Pozornost je věnována těm registrům, které obsahují osobní údaje. Jejich provozováním může docházet k zásahu do práva na soukromí a práva na ochranu osobních údajů. V této souvislosti je zvláště podrobně popsán katastr nemovitostí, dále matriky, evidence obyvatel, živnostenský rejstřík, informační systémy vedené správci daní a jiné registry. Zmíněny jsou také ostatní registry, jako například centrální registr řidičů, evidence občanských průkazů a cestovních dokladů, databáze účastníků veřejné telefonní služby, dále některé speciální registry jako je seznam advokátů, ústřední seznam znalců a tlumočníků a jiné. Práce se zmíní o provázanosti jednotlivých informačních systémů, spolupráci orgánů, které jejich informace využívají. Všímá si také zákonných podkladů, na základě kterých mohou správci konkrétních registrů některé údaje poskytovat. Práce se zabývá přístupem občanů k informacím z rejstříků, porovnává rejstříky z hlediska dostupnosti informací, zmiňuje nové trendy usnadňující přístup k informacím z veřejných rejstříků.
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