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Study of seasonal changes of water quality in Vír reservoir
Navrátilová, Martina ; Dolejš, Petr (referee) ; Chocholáčová, Hana (advisor)
Thesis deals with measuring of chosen indicators of water quality in Vír reservoir (temperature, pH, colour, turbidity, fluorescence of fykocyanin, concentration of chlorofyl-a, pheopigments, microcystin-LR, orthophosphates, nitrates, etc.). Samples were taken from the sampling profiles 10, 30 a 50 metres from absolute level and in the season from May to October was direct in reservoir measured a vertical profile by a multifunction sonde YSI 6600.
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Problems of humic matters as precursor of trihalomethanes (THMs) in water
Jelínková, Zuzana ; Dolejš, Petr (referee) ; Doležalová Weissmannová, Helena (advisor)
The bachelor’s thesis deals with qualities of humic matters, their origins, structures and occurrence in aquatic environment. There are suitable methods for determination of humic substances and processes used for their removing from water. The thesis describes disinfection of water and related origin of trihalomethanes. The aim of the experimental part of the thesis is to coagulate model humic water on the laboratory mixing column including suggestion of optimal dose of selected coagulation agent and comparison of effectivity of floccules separation by membrane filtration and centrifugation. Effectivity of the removal of humic matters was determined by measuring water absorbance at wavelengths 245 nm in a silica cuvette with optical 1 cm trajectory and at 387 nm in a glass cuvette with optical 5 cm trajectory. For evaluation of quality suspension concentration of residual iron of coagulation agent in water was determined.
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Aggregation reactions of chitosan in drinking water treatment
Leskovjanová, Jana ; Mega, Jaroslav (referee) ; Dolejš, Petr (advisor)
The diploma thesis deals with treatment of surface waters containing humic substances. The most often used method of surface water treatment is coagulation with subsequent separation of aggregates. In this study, only perikinetic coagulation phase was studied. It is the phase when aggregates are formed by the Brownian motion only, i.e. without mixing. Separation of the formed aggregates was made by centrifugation. Coagulation tests were made under the laboratory conditions with model humic water. Humic substances were added from a concentrate, which was taken from a natural peatbog. The influence of temperature on the coagulation process was studied, ranging from 5 to 22 °C. Chitosan (natural biopolymer) was used as coagulant. In present, it is not used in Czech water treatment practice yet. No effect of temperature was observed when chitosan was used as coagulant. Influence of temperature was also studied with the use of aluminium and ferrous sulphates, which are used in common praxis as coagulation reagents. Influence of the temperature was observed and is in agreement with previously reported data of pilot-plant experiments by other researchers. Spectroscopic methods were used to evaluate the coagulation efficiency and determine residual concentration of aluminium and ferrous coagulant. Chemical oxygen demand (COD) was determined for optimal doses. At first, coagulation tests were made under the laboratory temperature. This tests determined optimal aggregation time and optimal coagulant dose under low temperature. Afterwards, all coagulants used were compared at given temperatures.
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Dissolved Air Flotation – From Pilot Plant to Full Scale Implementation
Dobiáš, Pavel ; Hlaváč, Jaroslav (referee) ; Janda,, Václav (referee) ; Vávrová, Milada (referee) ; Dolejš, Petr (advisor)
The thesis deals with the use of dissolved air flotation (DAF) in water treatment technology in the Czech Republic. It summarizes the knowledge gained at pilot plant studies as well as the experience with full-scale flotation units which have been built in potable water treatment plants in the Czech Republic in years 2006-2018. This thesis provides a broad background of experimental studies of a modern separation process, which does have great advantages in the removal of natural organic matter and microorganisms from water in the drinking water treatment industry. In this thesis, there are presented some examples of the excellent efficiency of the microorganisms removal, both under the experimental conditions as well as water treatment plants, which were improved by DAF units installation in full scale. In addition to the high separation efficiency, it is shown, how DAF units could influence the subsequent separation steps as for example filtration through the granular media. The negative influence of the pre-ozonization on the DAF separation efficiency in Hradec Králové WTP is demonstrated too. The results of the pilot experiments support the idea, that the key condition for high removal efficiency is the optimal coagulation process chemistry. Design of pilot experiments was based on the factorial planning theory and some results are discussed in this thesis. The very big portion of the pilot experiments was made for estimating of the full-scale DAF design parameters before the water treatment plants reconstruction phase
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Application of trihalomethane formation potential to evaluation of drinking water treatment efficiency
Halešová, Barbora ; Dolejš, Petr (referee) ; Mega, Jaroslav (advisor)
The aim of bachelor thesis was to develop a literature search for the potential creation of oftrihalomethanes (THMs FP) as indicators of water quality in surface water treatment. The THM FP test was monitorated to evaluate the effectiveness of current technological methods of treatment of natural water with special consideration of water with increased content of humic substances. The attention was focused on comparison of the THM FP values with the normally applicable water quality parameters; it means the concentration of dissoluble organic carbon (DOC), UV254, CODMn, CODCr. The obtained evidence suggests that THM FP test allows sensitively assess water quality in term of content of chemically and biologically easily biodegradable organic substances. The potential of THM formation has been proved as a valuable tool for quantify non-specific organic contaminants in treated water, which can usefully complete previously used criteria for assessing quality of treated water.
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Karyotype evolution of cobweb spiders (Araneae: Theridiidae)
Večeřová, Hana ; Forman, Martin (advisor) ; Dolejš, Petr (referee)
Spiders (Araneae) are diversified order of the subphylum Chelicerata. Majority of the order belongs to group Entelegynae, as well as representatives of cobweb spider family (Theridiidae). Their noteworthy genus is Latrodectus, also known as "black widows". This thesis summarizes basic information about the genus, it's biology, phylogenetics and cytogenetics, with an overlap to genomics of cobweb spiders and their related species. Even though spiders' cytogenetics is an interesting field, particularly due to the occurance of unusual systems of sex chromosomes, some of the questions remain unanswered. A leading trend in entelegyne spiders is the reduction of diploid counts, where most mechanisms of the process remains unclear. Main aim of the thesis was to verify a potential of cobweb spiders as a model system for future studies of these changes. The genus Latrodectus may have potential because of showing suprisingly diverse karyotypes, which is unusual in Entelegynae. Despite their popularity, quality of karyotype data is poor and deserves to be revised. Nevertheless, the cosmopolitan L. geometricus is purposed as a keypart of promising model system for comparison of genome with modern cytogenomic approaches. Establishment of such model system could adress the questions about mechanism of karyotype...
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The Role of Spinneret Glands and Specific Features of Silk Production in Tarantulas (Araneae: Mygalomorphae)
Sýkorová, Barbora ; Říhová, Dagmar (advisor) ; Dolejš, Petr (referee)
This bachelor thesis is a review of scientific papers, monographs and internet sources, which focus mainly on the spinning apparatus and silk production in Mygalomorphae. The thesis is enriched with pictures that could help the reader to better navigate the topic. Spiders belong to arthropods. They are divided into the infraorders Araneomorphae, Mesothelae and Mygalomorphae. Spiders have a body divided into a cephalothorax and an opisthosoma, connected by a pedicel. The digestive system of spiders is specific in that it only allows them to take in liquid food. Almost all spiders have developed venom glands. Spinning activity is a very important feature of spiders. An important part of the spinning apparatus in the spinning nipples varies from family to family, but usually there is a reduction in their number. The basic functional and structural units of the spinning apparatus are the spinning glands, which transform on the surface of the spinning nipples into spigots, through which the silk is expelled to the surface. The silk is used by spiders to form snare or to form protective egg cases- cocoons. In the Czech Republic we can see three species of the family Atypidae (genus Atypus): Atypus affinis, Atypus piceus and Atypus muralis. KEYWORDS Spiders, silk glands, spigot, spidroin, family Atypidae,...
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Spider diversity research in relation to habitat conservation management.
Krajíčková, Kateřina ; Opatová, Věra (advisor) ; Dolejš, Petr (referee)
Spiders are a cosmopolitan and highly diversified group of invertebrates that play a very important role in the ecosystem. Thanks to their ubiquity in anthropogenic and economic ecosystems, we can consider them a suitable group that can be used for biological protection needs. Spider venoms and their silks also have potential uses in biotechnology in the future. Today, however, spiders face many threatening factors, including climate change, habitat loss, pesticides, acid rain, and other introduced invertebrate species. Spider conservation is currently addressed in several ways, using regional instruments such as the Bern Convention, the Habitat Directive and the IUCN Red List of Endangered Species. However, in the EU in particular, there is a lack of efforts to protect them not only in terms of evaluation but also in terms of regional and national legislation. However, the fact that they may be located in protected areas, such as national parks or protected landscape areas, also helps to protect them, which greatly helps to maintain their diversity. The biggest obstacle to spider protection is the lack of public support, which can be linked to ignorance and concern. These concerns could theoretically be addressed by pointing out that very few spider species pose a threat to humans and by educating...
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Aphidophagy among polyphagous predators
Valdecká, Miriam ; Řezáč, Milan (advisor) ; Dolejš, Petr (referee)
Aphids are among the most widespread insect pests in agroecosystems. So far, significant attention has been paid to their natural enemies, especially to specialized predators and parasitoids. There is less information about the influence of polyphagous predators, especially spiders and ground beetles. Therefore, the aim of this thesis is to summarize the knowledge about this topic. And focus on the advantages and disadvantages of aphidophagy in polyphagous predators. Key words: Aphid, aphidophagy, polyphagous, spider, carabid, predator
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