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The mechanisms and efficiency of uptake of selected micropollutants by crops irrigated with reclaimed wastewater
Šrédlová, Kamila ; Semerád, Jaroslav ; Šereš, M. ; Mrvová, M. ; Rozkošný, M. ; Cajthaml, Tomáš
Water scarcity and the quality of fresh water are important global issues, which relate to all areas of human activity. One of the possible ways of reducing water consumption in agriculture is using treated (recycled) wastewater for irrigation. However, when applying recycled wastewater or biosolids to crops, it is necessary to monitor the content of micropollutants. The Summary research report describes the mechanisms of uptake of selected micropollutants (perfluorinated alkyl compounds and pharmaceuticals) by crops during automated irrigation with recycled wastewater. A detailed literature review complemented by experimental data describes micropollutant bioaccumulation in the fruits of several plants, which represent an exposure pathway for humans. Furthermore, the risk of human intake of micropollutants from crops potentially contaminated when grown using this technology is outlined
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Biodegradation of a new type of polyurethane using various soil substrates
Valešová, Kateřina ; Innemanová, Petra (advisor) ; Cajthaml, Tomáš (referee)
Newly developed fully aliphatic polyurethane (PUR) for agriculture applications was exposed to aerobic biodegradation in soil (ASTM D5988-18) and in modification of this method also in standardized soil which is commonly used for ecotoxicological tests. Biodegradability was assessed by measuring released CO2 during the mineralization of the test material. PUR in the natural soil (according to D5988-18) reached 43 ± 15,0% mineralization and in the standardized soil 28 ± 9,9 %. Leachates of both types of soils containing PUR (and leachates of positive controls containing cellulose and negative controls containing pure soil) were tested for ecotoxicity with a marine bacteria Vibrio fischeri after the half-year biodegradation test. The biotest was performed because of the suspicion of toxic effect of dibutyltin dilaurate, which was used as a catalyst within the PUR production. Furthermore, a reduced biodegradation experiment in two variants was carried out (with higher amount of PUR and a corresponding amount of the pure catalyst) in the standardized soil and then the leachates were tested for the ecotoxicity as well. None of the leachates showed ecotoxic effects. A PLFA analysis was performed in addition to the biotest to examine a potential impact of PUR on a microbial diversity (compared to the...
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Endocrine disrupting compounds in the environment
Ezechiáš, Martin ; Cajthaml, Tomáš (advisor) ; Kočí, Vladimír (referee) ; Bláha, Luděk (referee)
A great variety of chemical compounds are released into the environment on a daily basis. Some of these compounds might be dangerous for human health or wildlife and might persist in the environment. In recent years, there has been a growing interest regarding chemical substances which could interfere with hormone biosynthesis and metabolism, cause a deviation from normal homeostatic control or negatively influence reproductive system. These chemicals are called endocrine disruptors. This dissertation thesis studied novel brominated flame retardants and selected pharmaceutical drugs as potential endocrine disruptors, based on their effect on hormonal receptors. Assays for estrogenic activities were also used for the evaluation of biodegradation experiments and for the validation of a novel mathematical model that could predict the effects of a mixture of toxic compounds. The results indicated that some of the tested chemicals were able to inhibit hormonal response of estradiol and testosterone and act as an anti-estrogens or anti-androgens. In the case of biodegradation experiments, the measured estrogenic activities were in agreement with the analytical concentrations of applied estrogens. Suggested mathematical model for mixture toxicity yielded a good fit with the experimental data from...
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Impact of litter quality on decomposition
Vicena, Jakub ; Frouz, Jan (advisor) ; Cajthaml, Tomáš (referee)
The text of the thesis is divided into two parts. The literature overview discusses the importance of decomposition to carbon cycling in soils and evaluation of biological, physical and chemical factors that affect decomposition. To understand the factors affecting the soil respiration is essential to improve the global carbon balance. Decomposition affects also the release of nutrients, soil fertility and other soil processes and properties. The very project aims at the impact of leaf litter quality assessment (specifically, the C: N: P ratio) on the rate of decomposition. The assumption is that the low C:N ratio initially accelerates the decomposition which quickly reaches its minimum. Conversely, at a high C: N ratio the rate of decomposition is initially slower and subsequently reaches its minimum, and the average value of decomposition will be higher than in samples with low C:N ratio. For litter which has undergone leaching phase none of the significant differences in respiration of the individual samples with different C:N were statistically proved.
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Optimization of endocrine disruptors determination in wastewater treatment plant sludge and application of the method in environmental samples.
Medková, Jaroslava ; Cajthaml, Tomáš (advisor) ; Tesařová, Eva (referee)
Hormonaly active compounds in wastewaters represent nowdays a serious problem. Proceses currently used in watewater treatment plants (WWTP) are unefficient in removing these compounds from contaminated wastewaters. The compounds are supposed to sorb onto solid sludge elements and sediments. In this work seven endocrine disruptors were detected in the sludge samples from WWTPs. A new sensitive method for detection of seven selected endocrine disruptors (4-nonylphenol, bisphenol A, estriol, 17β-estradiol, estrone, 17α- ethynylestradiol, irgasan) was developed. The method is based on accelerated solvent extraction (ASE), gel permeation chromatography (GPC) and solid phased extraction. For final extract analysis, gas chromatography coupled with mass spectrometry (GC/MS) was used. The efficiency of this method was tested using artificially contaminated sludge and the method was used to analyse real samples from several WWTPs in Czech Republic. The effect of sludge age on detection of individual analytes was assessed as well. The concentrations of endocrine disruptors measured in the samples reached up to 1 µg/g. The results are comparable or higher then those reported in other works and they show the necessity of further research on endocrine disruptors in the environment.
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Determination of white rot fungi Biomass during cultivation using analytical techniques
Vlasenkova, Tatiana ; Cajthaml, Tomáš (advisor) ; Frouz, Jan (referee)
The role of fungi in the soil ecosystems is well known. Exact determination of the fungal biomass is necessary for the understanding of their role in the cycle of soil nutrients, in the existing food chains of various animal types and in the soil aggregation. Bachelor's thesis is aimed at determination of white rot fungal (L. tigrinus, P. osteratus, I. lacteus, T. versicicolor) phospholipid-fatty acids and ergosterol (free and total) quantitative content with the subsequent comparison of the research results among themselves. Straw pellets were used as a sterile substrate for mushrooms. Their period of cultivation was 5, 8, 12, 16 and 20 days. The theoretical part describes methods for determining the microbial biomass, properties of ergosterol biosynthesis, lipids and fatty acids. Tools of gas and liquid chromatography, their use in determining the phospholipid-fatty acids and ergosterol in real samples are summarized. The experimental part of the procedure describes preparation of methylesters of fungi freeze-dried specimens that had previously been used in a biodegradation experiment. It just describes a method of determining fatty acids by gas chromatography, the extraction of ergosterol (free and total) and its subsequent determination using liquid chromatography. Based on the definition of...
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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...
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