National Repository of Grey Literature 126 records found  beginprevious81 - 90nextend  jump to record: Search took 0.01 seconds. 
Modelling dependence of chlorinated hydrocarbons biodegradation on changes of temperature and redox conditions in ATES sytems
Havlíková, Barbora ; Mls, Jiří (advisor) ; Datel, Josef (referee)
The Aquifer Thermal energy Storage (ATES) system is one of the most important techniques, that use the aquifer as an energy storage for heating and cooling the buildings. The operation of the ATES system is based on pumping the cold ground water into the buildings during the summer and then injecting the warmer water back into the aquifer. During the winter, the direction is reversed. Warm water is pumped to the buildings, where it serves for the heating system and then it is injected back into the aquifer. The ATES system has a main effect on the chemical composition of ground water, because of changes in the temperature of ground water, mixing of water from different redox zone and increasing of ground water flow in the neighbourhood of the wells of the ATES system. The modification in chemical composition and temperature could influence the behaviour of contaminants. If we want to install the ATES system into a contaminated aquifer, we have to know, if the ATES system would influence the behaviour of the contaminant plume positively or negatively. This study was made to increase the understanding of the dependence between changes of temperature and oxidation-reduction conditions in the ATES system and biodegradation of chlorinated hydrocarbons. In the first part, several scenarios were modelled...
Screening of possibilities of deep subsurface microflora to decompose selected organic compounds
Kuanysheva, Assel ; Frouz, Jan (advisor) ; Kryštůfek, Václav (referee)
Screening of possibilities of deep subsurface microflora to decompose selected organic compounds Abstract The aim of the study is to test the deep microflora bacterial strains for their ability to grow in oily environment, aliphatic hydrocarbons and toluene were taken as examples of aromatic hydrocarbons and where the cultivation of selected strain, were produced for testing its growth and microbial activity of selected strains in conditions simulating soil conditions; assess the usability these strains in practical remediation of contamination by oil. This thesis deals with the evaluation of possible use of selected strains of deep microflora for oil decomposition. It is evident, that some groups of microorganisms living in the Tertiary claystones at depths of 30-450 m below the surface are the biodegradable fossil organic matter type of kerogen. Chemical findings indicate that, this organic matter consists of various lengths of aliphatic chains, and thus the assumption that microorganisms decomposing kerogen might be able to disassemble oil and petroleum products. The findings of our experiment indicate that benzene and toluene, as well as kerogen are highly resistant to organic compounds and evidence of microbial degradation are rare. Utilization of oil as representative aliphatic compounds is better...
Vliv technologie kompostování v městské kompostárně na kvalitu produktu
BARTUNĚK, David
The thesis is about the processing of biological waste in the Czech composting plants with focus on the quality of the final compost. In 2016, there was more than 160 composting plants in the Czech Republic. The thesis is focused on the most widely used technologies in small composting plants in terms of their impact to the quality of the final product, including the follow-up of individual indicators during composting. The best technology in my work is based on a higher decomposition temperature (85 ° C) at the first stage of composting. The practical part of thesis is focused on the measurement of ion-exchange capacity according to Sandhof as a main material for the overall evaluation of the functionality of composting. The final value shows the compost quality of the individual composting plants in terms of ion exchange flexibility of the produced substrate. The best result was achieved with the combination of composting boxes and composting in the belt heaps. The value of the ion-exchange capacity with the best technology was 52.8 mval .100 g of the soil, with 77.9% of the distributed biowaste. You have to expect with an average annual costs of composting about 1,696,000 crounds in the Czech republic, when you are designing small functional composting plant with production of 2000 tons of the compost per year.
Biodegradable plastics
Schifferová, Zuzana ; Jan, Vít (referee) ; Molliková, Eva (advisor)
The aim of this bachelor theses is to discuss the process of biodegradation occurring with biodegradable polymers including factors affecting this process. The theses also introduces some types of biodegradable plastics including their properties. At last it discusses waste management of these plastics and their ecological impact.
Utilization of PHA producing bacteria in bioremediation technologies
Šuráňová, Zuzana ; Sedláček, Petr (referee) ; Obruča, Stanislav (advisor)
The aim of this work is study of utilization of PHA producing bacteria in bioremediation technologies. For this study were used bacteria Pseudomonas putida KT2440 and two isolates from soil contaminated by petroleum - Pseudomonas gessardii (D2) a Pseudomonas fulva (D3). The experimental part describes especially study of feather biodegradation using selected microbial strains. All the tested bacterial strains were capable of feather degradation and utilization as the sole carbon source. During biodegradation experiment, we monitored weight loss of feather, protease and keratinase activity, concentration of bacterial biomass and PHA content as well as pH. The highest biodegradation ability and keratinase activity was observed in Pseudomonas putida. None of tested bacteria accumulated detectable amount of PHA during growth on waste feather, nevertheless, bacterial biomass grown during feather degradation can be used as an inoculum for PHA production on waste frying oil and octanoic acid. Using this experimental setup, high PHA content (54% of cell dry weight) was achiaved in Pseudomonas putida. Another part of the thesis deals with biodegradation of petroleum oil. The highest capability of growth on this carbon source were determined in Pseudomonas fulva.
New flame retardants in the environment
Ezechiáš, Martin ; Cajthaml, Tomáš (advisor) ; Kočí, Vladimír (referee)
In the recent years, many research articles focused on endocrine disrupting compounds in the environment. Some of these compounds are listed in a group named brominated flame retardants. However, only few articles investigated endocrine activity of several "new" brominated flame retardants. These chemicals such as 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) or bis(2-ethylhexyl) tetrabromophthalate (TBPH) are newly used due to ban of some previously most produced brominated flame retardant mixes. In this study, we used two recombinant yeast screens to measure estrogenic, androgenic, antiestrognic and antiandrogenic activities of some alternative brominated flame retardants. We also used ligninolytic fungi to investigate biodegradation of these compounds. Our results suggest, that 2,4,6-tribromophenol (TBP) may be a new environmental endocrine disruptor. This substance showed antiestrogenic and antiandrogenic activity in our tests. 1,2-bis(2,4,6- tribromophenoxy)ethane (BTBPE) had certain antagonistic activity too. In the biodegradation experiment, only three compounds showed significant degradation during the test period. No biodegradation have been observed for other compounds. In this study, we applied gas chromatography with mass spectrometry to analyze these "new" flame retardants. Method for gas...
Isolation and characterization of microsomal fraction of fungus Pleurotus ostreatus and its role in the degradation of 17α-ethinylestradiol
Valášková, Petra ; Černá, Věra (advisor) ; Hodek, Petr (referee)
A synthetic hormone 17α-ethinylestradiol (EE2) which is a component of hormonal contraception pills has been identified as a main component of the endocrine-disrupting compounds (EDc). EDc are substances that mimic natural hormones in their action. Recently their amount especially in the groundwater and the surface water has been increased, which results in a negative impact on the hormonal system especially of aquatic organisms. Since it is not easy to replace these substances from the environment by conventional techniques other possibilities of their biodegradation are examined. White rot fungi, which are able to degrade lignin in nature, have promising biodegradation abilities towards many pollutants. These fungi contain a wide range of non-specific extracellular and intracellular enzymes that play an important role in the degradation. This bachelor thesis was targeted on the study of a white rot fungus, Pleurotus ostreatus, and especially on the degradation potential of its intracellular enzymes in the biodegradation of EE2. Initially, the ability of fungi Pleurotus ostreatus to degrade EE2 in vivo was tested. During the 48 hour incubation there was replaced 95,5 % of EE2. However, the role of cytochromes P450 (CYPs) in a metabolism of EE2 was not confirmed in this experiment by reason that an...
Isolation and characterization of catechol 1,2-dioxygenase of Candida tropicalis
Jechová, Jana ; Stiborová, Marie (advisor) ; Martínková, Markéta (referee)
Candida tropicalis yeast is a microorganism that possesses high tolerance for phenol and strong phenol degrading activity. This yeast is capable of utilizing phenol as the sole source of carbon and energy without formation of any secondary waste product. Catechol-1,2- dioxygenase was isolated from cytosolic fraction of this yeast by the procedure consisting of chromatography on DEAE-Sepharose and gel permeation chromatography on Sephadex G- 100. The catechol-1,2-dioxygenase was purified to homogeneity. The enzyme activity was followed by HPLC (catechol consumption and/or cis,cis-muconic acid formation). The activity profiles at different temperatures showed temperature optimum of 30řC. Kinetic characterizations were studying in different values of pH. The values of Km and Vmax of 0,52 mM and 17,2 nM/min for consumption of catechol, respectively, and 0,34 mM and 12,6 nM/min for formation of cis,cis-muconic acid, respectively, were found at optimum pH of the reaction, pH 7,6.
Characterization of bacterial genes encoding DbtC-like extradiol dioxygenase with bioremediation potential for aromatic compounds in locality Hradčany
Šnajdrová, Renata ; Bořek Dohalská, Lucie (advisor) ; Nešvera, Jan (referee)
Aromatic pollutants pose a serious environmental problem. Petroleum and its derivates belong to the most abundant contaminants in the Czech Republic and their sanation is a priority objective for improving the life quality of the population. Bioremediation is a technology taking advantage of the natural capacity of soil and water microbial community to degrade environmental pollutants. Deeper understanding and detailed knowledge on specialized bacterial species, pathways and genes is required for selection, optimization and application of targeted bioremediation approach and for monitoring of its results. Recent analysis of a metagenomic library constructed from highly contaminated soil of the former military air-base Hradčany has identified a novel group of catabolic genes encoding extradiol dioxygenase similar to DbtC of Burkholderia sp. DBT1. The DbtC-like enzymes are among the three priority groups of extradiol dioxygenases with biodegradation relevance for the locality. The present study of soil bacterial isolates and metagenomic fosmid clones harboring the genes of interest gained evidence about the dbtC-like genes as a part of highly mobile gene cassette. Transposon insertion mutagenesis identified the genes joined with the expression of the extradiol dioxygenase activity. The dbtC-like genes were...

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