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Bioremediation of persistent aromatic pollutants
Stella, Tatiana ; Cajthaml, Tomáš (advisor) ; Mihaljevič, Martin (referee) ; Tesařová, Eva (referee)
The remediation of persistent chlorinated aromatic compounds has become a priority of great relevance due to the teratogenic, carcinogenic and endocrine-disrupting properties of these xenobiotics. The use of biological methodologies for the clean-up of contaminated sites, collectively referred to as "bioremediation", has been gaining an increasing interest in recent years because it represents an effective, cost-competitive and environmentally friendly alternative to the physico-chemical and thermal treatments. In this respect, "white rot" fungi, an ecological subgroup of filamentous fungi, display features that make them excellent candidates to design an effective remediation technology ("mycoremediation"). In spite of this, fungi have not been widely exploited for their metabolic capabilities and the mechanism by which they are able to degrade the aforementioned pollutants has not been fully elucidated yet. Within this frame, the present Ph.D thesis was aimed at: i) assessing the efficiency of different mycoremediation strategies for the clean-up of a polychlorinated biphenyl (PCBs)-contaminated soil; ii) understanding the fungal degradation pathways of polychlorinated biphenyls and their major metabolites, namely chlorobenzoic acids (CBAs) and hydroxylated polychlorinated biphenyls (OH-PCBs). i)...
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Changes of ecosystem loads in longitudinal profile of anthropogenic polluted river
Kohušová, Kateřina ; Tonika, Jaroslav (advisor) ; Cajthaml, Tomáš (referee) ; Komínková, Dana (referee)
Disertační práce Změny zátěže ekosystému v podélném profilu antropogenně ovlivněného toku Kateřina Kohušová Changes of ecosystem load in longitudinal profile of antropogenically influenced river ABSTRACT To determine anthropogenic load of the Bílina river ecosystem we monitored concentrations of selected heavy metals (As, Cd, Hg, Pb, V, Zn) and specific organic substances (PAH, PCB, HCH, HCB, DDT) in three different matrices: surface water, biofilms and sediments. In the longitudinal profile of the river, four sampling profiles were determined (B1 - B4), mapping different parts of the river. The monitoring took place from 2005 to 2008. Concentrations of the substances monitored in surface water showed a decrease in load compared to the values from ten years ago. The concentrations found in surface water showed clear tendency of pollution in the longitudinal profile; the load increased downstream and profiles B3 and B4 mid- and downstream had the highest concentration. In the case of some concentrations of substances in surface water there is a trend of the majority of values being below the detection limit by the given methods of analysis. This shows a decrease of load in the river but the positive trend was invalidated by variations in maximum concentrations. Even though these variations were rare and...
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Study of main mycoremediation aspects - effect of bioavailability, biodegradation and toxicity of organic pollutants
Čvančarová, Monika ; Cajthaml, Tomáš (advisor) ; Kočí, Vladimír (referee) ; Bosáková, Zuzana (referee)
Many organic compounds are released to the environment and can be harmful to living organisms. These compounds are often persistent and toxic. Some are mutagens, carcinogens, endocrine disruptors or they can cause an increase in bacterial resistance. They tend to accumulate in nature and their transformation is a long-term process. Therefore, various remediation techniques are needed for decontamination. Remediation and bioremediation processes depend on many factors which should be critically evaluated. This dissertation thesis studies the relationship between bioavailability, biodegradation and toxicity of polychlorinated biphenyls, polycyclic aromatic hydrocarbons and fluoroquinolone antibiotics. These compounds of different origin, character and properties were degradated by ligninolytic fungi. Desorption behaviour of pollutants from historically contaminated sites, degradation potential of ligninolytic fungi, ongoing degradation mechanisms, transformation products and their toxicity were studied as important factors for evaluation of mycoremediation and its environmental impact. The results show that determination of bioaccessible fraction by sequential supercritical fluid extraction is very useful for precise prediction of biodegradability of pollutants. The evidence that ecotoxicity and...
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Effects of microplastics on earthworm gut microbiome, their immunity system and metabolome
Flohrová, Tereza ; Cajthaml, Tomáš (advisor) ; Lišková, Petra (referee)
Microplastics are widespread pollutants found in aquatic, atmospheric, and soil environments. They are released directly into the soil, for example, from mulch films and textiles. Microplastics accumulate in the soil and can have a negative impact on soil microfauna and macrofauna. Earthworms, acting as ecosystem engineers, and soil and gut bacteria play a significant role in biogeochemical cycles of biogenic elements. Disruption of earthworm function, their gut bacteria, or soil bacteria could have an impact on the entire ecosystem. In the context of this thesis, earthworms of the species Apporectodea sp. were exposed to microplastics from polypropylene black nonwoven textile at concentrations of 1 g/kg soil and 0.0265 g/kg soil for 14, 28, and 56 days. DNA was sequenced to identify bacteria from the earthworm gut, gut contents, and rearing soil. Additionally, untargeted analysis of metabolites from the earthworm body and extraction of immune cells from earthworms using three different methods were conducted. No significant changes caused by the presence of microplastics were found in the representation of bacteria from the gut, gut contents, and soil, but statistically significant changes in the metabolome were detected. A sufficient number of immune cells could not be isolated from the...
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Microplastics in deep-sea fish
Fürychová, Barbora ; Cajthaml, Tomáš (advisor) ; Innemanová, Petra (referee)
Microplastics have become a significant problem in marine ecosystems, posing a serious threat to the biodiversity and stability of these environments. This bachelor's thesis focuses on investigating the presence of microplastics in the digestive tracts of deep-sea fish in the Indian Ocean. These fish represent interesting model organisms that can aid in understanding the distribution of microplastics in the marine water column. The introductory part of the paper summarizes the existing knowledge on microplastics, their occurrence, methods of analysis and the presence of microplastics in the aquatic environment. Particular attention is paid to deep- sea fishes, whose role in marine ecosystems is crucial. In the experimental part, detailed analyses of fish digestive tract samples were performed to detect and identify microplastics. The study confirmed the presence of microplastics in the digestive tracts of deep-sea fish, and various types of polymers were identified, including polystyrene, nylon, polyethylene terephthalate, polyvinyl chloride and polyester. This undergraduate thesis is the first study ever to demonstrate that microplastics are found in deep- sea fish in the western Indian Ocean. The conclusions of this thesis underscore the urgency of the situation regarding contamination of the...
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Fate of micropollutants during vermicomposting
Grasserová, Alena ; Cajthaml, Tomáš (advisor) ; Macek, Tomáš (referee) ; Lhotský, Ondřej (referee)
Vermicomposting is recently becoming a rather popular environmentally friendly technique for stabilizing biowaste, including sewage sludge. There is an effort to utilize the sewage sludge as fertilizer on agricultural land. But apart from nutrients, the sludge also contains harmful pollutants, which subsequently after its deposition on fields can be taken up by plants and organisms contaminating the food chains. Micropollutants, the substances that can be found throughout the environment in trace concentrations, are one of the pollutants occurring in sludge. It is for example pharmaceuticals and personal care products, per- and polyfluoroalkyl substances, or pesticides. Their negative effects are known - they can be for instance endocrine disruption, antibiotic resistance, or the development of cancer. Although the deposition of sewage sludge on fields as a fertilizer is one of the main introduction routes of micropollutants to the environment, the content of micropollutants before deposition is not monitored nor regulated. This dissertation focuses on the fate of micropollutants during vermicomposting, especially in sewage sludge substrates. The vermicomposting method was applied to stabilize coffee spent grounds and sewage sludge obtained from distinct wastewater treatment plants mixed with...
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Methods of sewage sludge treatment for agricultural applications with respect to micropollutants
Vítková, M. ; Komárek, M. ; Wickramasinghe, N. ; Pohořelý, Michael ; Moško, Jaroslav ; Hušek, Matěj ; Cajthaml, Tomáš ; Grasserová, Alena ; Čechmánková, J. ; Vácha, R. ; Zimová, M.
The aim of the methodology is to describe the possibilities of sewage sludge treatment by composting and pyrolysis for the application in agriculture, with particular respect to the so-called micropollutants, but also to conventional pollutants, and to assess the risks of treated sludge for the soil environment and the uptake of (micro)pollutants by cultivated crops. The methodology is based on the results from laboratory and field experiments of a three-year project and on a critical approach to sludge as a potentially hazardous waste on the one hand and a recyclable source of nutrients on the other.
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Microplastics in solid matrices of the environment
Pospíchalová, Eliška ; Cajthaml, Tomáš (advisor) ; Innemanová, Petra (referee)
Microplastics, plastic particles of 5 mm-1 nm in size, are now widespread across different ecosystems. The increasing amount of microplastic contamination of aquatic and terrestrial environments requires the development of standardized methods for their separation and analysis. One of the main vectors of microplastic input to terrestrial ecosystems is through sewage sludge. The sludge is recycled for fertilization and reclamation due to its high organic matter content. Scientists have already been able to quantify and identify a range of microplastics in sewage sludge of different sizes, polymer types, shapes, etc. This thesis focuses on the optimization of existing methodologies to extract microplastics from solid environmental samples and their subsequent qualitative and quantitative analysis. The steps required for sample pre-treatment prior to analysis, namely reduction in organic matter content by the Fenton reaction process and density-based separation of microplastics by flotation in saturated NaI solution (1.8 g/cm3 ) using centrifugation, were optimized. Microplastics in size fractions of 20-40 μm and 150-300 μm were fabricated and introduced into flotation and total recovery experiments of the methodology to determine the recovery. Fluorescence microscopy was chosen for quantitative...
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Low-energy recycling of poly(ethylen terephthalate) waste
Slabá, Jitka ; Beneš, Hynek (advisor) ; Cajthaml, Tomáš (referee)
This thesis deals with a new low-energy method of chemical recycling of poly(ethylene terephthalate) (PET) using natural oils as reagents and microwave irradiation to accelerate depolymerization. The results of experiments with PET waste and castor oil, when the reaction mixture was heated in microwave reactor, showed that a complete depolymerization of PET chain has occured. Optimal conditions for the depolymerization PET were established: wt. ratio of PET / castor oil = 1 / 9.7, when the molar ratio of ester bonds of PET / hydroxyl groups of castor oil = 1 / 2.7, catalyst : zinc acetate at wt 1% from the PET mass, reaction temperature ranging from 235 to 245řC and the reaction time 60 min. Decomposition experiments also showed, that microwave irradiation accelerated decomposition of PET. Depolymerization reactionin MW reactor was complete at 6x shorter reaction time than the decomposition in the classically heated reactor. The results of analysis showed that the resulting product,the recyclate, was composed of unreacted castor oil and polyol products, that contained partially or fully esterified structural unit of PET, which were ended by ester-linked units of castor oil.
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Community vermicomposting within student dormitories
Lipan, Andrej ; Innemanová, Petra (advisor) ; Cajthaml, Tomáš (referee)
Through the Green Study Room pilot project, the thesis explores the integration of a circular bio-waste management model at the Otava College under the administration of Charles University. The thesis describes the circular economy as an essential method for the efficient management of bio-waste, which is supported in particular by legislation and strategic goals for sustainable development of states, cities and institutions. A questionnaire survey was conducted to assess the awareness and interest of students in establishing a community vermicomposting site. The reconstruction of the study room creates a space to prevent the generation of biodegradable waste on the dormitory premises. Vermicomposting was used as an eco-friendly approach that takes advantage of earthworm's natural ability to convert organic waste into nutrient-rich compost. The establishment of a community shared study room sets the stage for ongoing projects in the areas of centralized bio-waste management, student education, and social-psychological phenomena associated with the transition to a more sustainable society. It also creates an ideal space for seminars, workshops and activities of the university in the field of improving the living standards of students staying at Otava College. The incorporation of the community...
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