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Thorium in environment
Adam, Rostislav ; Soudek, Petr (advisor) ; Petrová, Šárka (referee)
All known isotopes of thorium are radioactive, 6 of them occur in nature decay chains. Thorium forms mainly cation Th4+ . Because thorium behaves like REE, Ce, Zr, Hf, Sc and U, it is a problem with thorium separation. There is requested leach thorium from ore for production of thorium. Monazite is mostly used for industrial production of Thorium. Electrolysis or chemical reduction are the most spread technologies for metal thorium production. For determination of thorium can be used many methods. Currently there is are usualy used radio-spectrometry or mass-spectrometry for determination of Thorium. Thorium occurs in small amounts in all parts of environment. Most of naturally occuring thorium are in the solid part of environment. Radioactive decay of thorium are using in geochronology. Thorium could be use in future as nuclear reactors fuel. Some other usage of thorium are catalyst in organic synthesis, Welsbach lamps or non-silicate glass. Thorium have also some chemical toxic efects for all organism, but more serious problem is its radioactivity. Final product of radioactive decay is lead. Non-stable products are radium, radon, bismuth, thalium and polonium. All products of radioactive decay have some specific chemical toxicity. 1
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How do plants manage to survive on toxic spoil-mining sites? Physiological and structural properties of plants on substrates with high As and Hg contents
Kovářová, Monika ; Albrechtová, Jana (advisor) ; Soudek, Petr (referee)
The heavy metals contamination of environment represents a worldwide problem lately. Heavy metals cause harmful effects not only to plants, but also to other organisms. Throught their acumulation in plant biomass, heavy metals enter a food chain and could negatively influence the human health. The impact of heavy metals on plants and their defence mechanisms against toxicity of heavy metals have been in focus of plant physiology and ecology research for decades. Importance of this topic arises from plant role in environment, ecosystem services and in human nutrition. Investigation in proces and mechanisms of heavy metal hyperacumulation in plants offer progress in fytoremediation and genetic engineering. The experiments on agricultural crops show how heavy metals enter the food chain and how they affect the crop yield. The aim of this thesis is to summarize information about heavy metals' effects on plants. The thesis is focused on arsenic and mercury, because the Czech Republic have also problem with heavy metals contamination and these two metals occur in high concentration in the spoil banks and soils adjacent to the lignite mining areas of Sokolovsko. The spoil banks with heavy metal content have to be revegatated, thus, the topic of their effect on plants is of high importance. In the first part of the...
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Accumulation of uranium by plants cultivated under laboratory conditions
Buzek, Martin ; Soudek, Petr (advisor) ; Petrová, Šárka (referee)
The ability to accumulate uranium was tested on 20 different cultivars and GMOs of Nicotiana spp. grown in Hoagland's hydroponic medium indoors. Apart from the accumulation and translocation of uranium in plants, the effects of genetic modifications and adaptations of hydroponic medium on the ability of plants to accumulate uranium were tested. N. glauca, N. tabacum cv. M 51 and GMO M 51 Pro seemed to be the best plants for accumulation of uranium. Concentrations of uranium in these plants grown in medium with 0,5 mM of uranium were as high as 31.28 mg/g dry weight in roots and 0.21 mg/g in upper parts. N. tabacum cv. La Burley 21 and GMOs TRI2 - T1 and TRI2 - T2 were tested for accumulation and translocation of uranium. Highest concentration was 72.49 mg/g in roots, 4 mg/g in stems and 1.1 mg/g in highest leaves for plants cultivated in medium with 1 mM of uranium. Absence of phosphate in the hydroponic medium resulted in increased accumulation of uranium.
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Mechanism of uptake of heavy metals and organic compounds by plants
Berkyová, Petra ; Soudek, Petr (advisor) ; Petrová, Šárka (referee)
Heavy metals and organic compounds represent a great problem for environment. Therefore, attention is paid to the development of techniques for removing these pollutants from the sites of pollution. One of the possibilities is that heavy metals and organic compounds are removed from soil by using fytoremediation. Fytoremediation uses the ability of some plant species to uptake toxic compounds from soil and accumulate these compounds in its tissues. These plants are able to tolerate higher amounts of toxic compounds than it's usual because of the broad range of detoxification mechanisms, which are taking place in these plants. After the root uptake, heavy metals may be chelated by phytochelatins, metallothioneins or other chelators and subsequently stored in vacuoles. Transport of metal ions and metal complexes between cells compartments is mediated by many specific transport proteins. Detoxification mechanisms of organic compounds involve transfomation, conjugation and store of these compounds in plant tissues.
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APPUCATION OF A SHORT-TIME HYDROPONICS FOR SELECTION OF APPROPRIATE DECIDUOUS WOODY PLANTS SPECIES FOR REMEDIATION PURPOSES
Malá, J. ; Cvrčková, H. ; Máchová, P. ; Dostál, J. ; Soudek, Petr ; Šíma, P.
A rapid trial of accumulation capacities for heavy metals Pb, Cd, and Cr of selected fast-growing deciduous woody plant species is presented. The Sorbus aucuparia, Populus tremula x P. tremuloides, Salix x blanda, S. viminalis, S. miyabeana, and S. elbursensiswere clonally micropropagated by induction of organogenesis. Samples of roots and aboveground parts from plantlets grown in aseptic conditions in agar semisolid substrate and hydroponics media supplemented by the heavy metal salts were taken at 2, 4, and 8 days of cultivation.The concentrations and distributions of the accumulated metals were determined using the ICP-OES method and verified by autoradiography. Practically, amounts of accumulated heavy metals increased linearly up to the end of the experiment and were higher in the roots than in aboveground parts in both, the agar cultures and hydroponics. It could be concluded that all tested species displayed a high efficacy of metal uptake and could represent prospective trees for phytoremediation of polluted soils.
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Phytoremediation of air - plans and reality
Vaněk, Tomáš ; Maršík, Petr ; Soudek, Petr
Results obtained so far indicate that selected plants can be effectively used to remove contaminants from the air, both horizontally and especially near sources of contamination, such as roads. When choosing plants, it is necessary to pay attention to their sorption capacities, as well as their ability to survive in contaminated sites, which are also exposed to other stresses such as lack of moisture and salinity.
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EVALUATION OF EFFECTIVITY OF PHYTOREMEDIATION METHODS
Soudek, Petr ; Petrová, Šárka ; Podlipná, Radka ; Fialová, Zuzana ; Malá, J. ; Benešová, Dagmar ; Kočí, V. ; Kafka, Z. ; Vaněk, Tomáš
Phytoremediation methods are very dynamically booming segment of remediation technologies in present time. These methods used plants and microorganisms for extraction, and in case of organics for degradation, of xenobiotics. Ability of plants involved in these detoxification reactions is depend not only on ability to uptake of xenobiotics and on enzymatic aparatus of tested plant species, but also on toxicity of accumulated contaminant and on toxicity of potential byproducts.
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