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Glycerolipids and carotenoids in microalgae: the implications in ecophysiology and applied phycology
Střížek, Antonín ; Nedbalová, Linda (advisor) ; Brányiková, Irena (referee) ; Barreira, Luísa (referee)
Lipids are basic biomolecules found in all organisms. They have a key function as structural molecules forming cell membranes, and, in the form of fats and oils, energy is also stored. There are a huge number of lipid types that have other functions, for example, in cell signaling, enzyme support, protection against stress, and others. Microscopic algae are the main primary producers in both freshwater and marine ecosystems. Therefore, algal biosynthesis has a fundamental effect on the trophic networks of aquatic ecosystems and ultimately on humans. The environment affects the ecophysiology of algae, which is reflected in their biochemical composition, i.e. in the composition of their lipids. This work is focused on two groups of lipids, namely glycerolipids, which consist of fatty acids, and carotenoids, which are photosynthetic pigments with antioxidant and photoprotective properties. In these groups of lipids, the target substances were further selected, namely polyunsaturated fatty acids and the carotenoid fucoxanthin belonging to xanthophylls. These substances are important not only in the ecophysiology of algae, but they are valuable substances that have positive effects on the human organism and, with the help of optimized cultivation, could be obtained from algae for industrial production...
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Occurrence and removal of polluting organic substances during drinking water treatment
Prokopová, Michaela ; Pivokonský, Martin (advisor) ; Brányiková, Irena (referee) ; Kříženecká, Sylvie (referee)
Water sources pollution by natural organic substances and anthropogenic micropollutants is a global problem with a significant impact on water treatability and drinking water quality. One of the current topics is the proliferation of algal and cyanobacterial cells and the associated release of algal organic matter (AOM). The presence of AOM in drinking water sources can deteriorate the water's taste and odour or serve as precursors of disinfection by-products., especially in the case of a high proportion of the non-proteinaceous AOM, which is difficult to remove by conventional coagulation/flocculation. A part of this thesis is devoted to the composition and characterization of AOM, its chemical coagulation and electrocoagulation, and the assessment of the ozonation of the non-proteinaceous AOM during drinking water treatment. The second part of this thesis deals with the occurrence, characterization and removal of persistent anthropogenic substances, namely microplastics (MPs) and per- and polyfluoroalkyl substances (PFAS), during the drinking water treatment. Based on the results of ozonation of the non-proteinaceous AOM fraction (NP), it was found that ozonation caused a change in the surface charge, molecular weight or partial mineralization of NP, depending on ozonation conditions (O3 dose, pH...
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Experimental Report, Period 9-12/2017, Project: Electrocoagulation Unit for Microalgal Biomass Separation.
Brányiková, Irena ; Vojtěchovský, R. ; Čermáková, Lenka
Production of microalgae in the world is increasing every year, but their use in food, cosmetics, feed and biofuel production is still limited by the high production price and high energy input. The substantial part of the energy costs lies in the separation of algal biomass from the medium, which is most often performed on plate centrifuges. The harvest concentration of algal suspensions in most cultivation systems ranges between just 1-5 g/L. Therefore, to obtain 1 kg of dry biomass, it is necessary to remove 200 to 1000 liters of water (by centrifuging and then drying). This amount of water and thus the energy input can be reduced via flocculation added as a pre-step prior to centrifugation. Electrofloculation is type of floculation, where the flocculant is directly formed by dissolving the electrodes. Suitable electrode material and parameter set enable obtaining of biomass, which is not contaminated by chemical flocculants and meets requirements for food stuff. The main objective of this project is to develop a continuous electroflocculation device suitable for these purposes.\n
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Experimental Plan for the Project: Electrocoagulation Unit for Microalgal Biomass Separation.
Brányiková, Irena ; Vojtěchovský, R. ; Čermáková, Lenka
Electrofloculation (electrocoagulation) of microalgae is a highly complex process involving a number of very complex transport, electrochemical, hydrodynamic and surface phenomena. The description of this process at the level of single mechanisms involved is too complicated and experimentally demanding, fortunately it is not absolutely necessary for the practical application. The electrofloculation was therefore approached by an engineering method that identified the criteria (range) of the desired variables and the main factors that affect them. For these factors, partial factorial experimental plans were designed.
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