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Effect of active ingredients to the activity of cementing compound with non-alkaline accelerator additive for sprayed concrete.
Závacký, Jakub ; Hela,, Vlastimil (referee) ; Hela, Rudolf (advisor)
The bachelor thesis deals with the problems of the sprayed concrete with the focus on usage of the active ingredients with non-alkaline accelerator additive. The theoretical part covers the current level of knowledge of how the active ingredients are used in the sprayed concrete and their influence on the process of hydration. In the experimental part the reactivity of cementing compound with non-alkaline accelerator on the basis of aluminium sulphate were compared in a laboratory when the active ingredients (such as slag, fly-ash and very fine limestone) were used. The cements CEM I 42,5 R, made by different producers were verified on the basis of the setting time and early strength gain using the Vicat needle to examine the mechanical properties after 6 and 24 hours.
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Influence of preoxidation by potassium permanganate on coagulation of nonproteinaceous compounds produced by alga Chlorella vulgaris
Přech, Jiří ; Pivokonský, Martin (advisor) ; Novotná, Kateřina (referee)
6 Abstract: The presence of phytoplankton and its products (AOM) in source water is a current challenge in water treatment processes. The production of AOM increases with anthropogenic eutrophication of ecosystems. AOM impair the water treatment processes and may form harmful disinfection by-products. The traditional water treatment process is a coagulation, which is very efficient in removing phytoplankton cells, but this is not the case when removing some kinds of AOM. Especially its nonproteinaceous fraction with low molecular weight, which can represent majority of total organic carbon, is removed with very low efficiency. The removal of AOM by coagulation can be enhanced by preoxidation. This thesis examines the influence of preoxidation by potassium permanganate of nonproteinaceous fraction of COM of algae Chlorella vulgaris on its coagulation by aluminium sulphate and polyaluminiumchloride. To compare, solutions with nonproteinaceous COM were coagulated with and without preoxidation by five different doses of permanganate (0,025; 0,05; 0,1; 0,15 a 0,2 mg KMnO4 mg-1 DOC). The doses of permanganate and time need for oxidation (30 minutes) were determined by decreased DOC and permanganate during preoxidation experiments. The maximal DOC removals achieved both with and without preoxidation were 17 %...
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Coagulation of non-protein algal organic matter
Lukeš, Jan ; Pivokonský, Martin (advisor) ; Novotná, Kateřina (referee)
The diploma thesis deals with characterizing properties of non-proteinaceous cellular organic matter (COM) of green alga Chlorella vulgaris in connection with its coagulation using aluminium sulphate and polyaluminiumchloride. As a part of this work, interaction mechanisms were also studied. It has been found out that non-proteinaceous COM of Chlorella vulgaris is made up by saccharides (25 % DOCNP, 21 % of dry biomass of non- protein matter) and other unspecified non-protein substances. It has been found out by fractionation of molecular weights that non-protein COM is formed primarily by substances with MW < 3 kDa and substances with MW > 100 kDa. Coagulation by aluminium sulphate taken place in interval pH 5 - 8,5 and coagulation by polyaluminiumchlorid taken place in interval pH 7 - 10 depending on coagulation agent dose. The maximum DOC removals were 17 - 22 % depending on selected coagulation agent, on its dose and pH. Polyaluminiumchloride showed higher DOC removal rates than aluminium sulphate. The highest effectiveness of coagulation was in the area of neutral pH for both agents. In all the coagulation tests the values of residual concentrations of aluminium were higher than the hygienic limit for drinking water (0.2 mg.L-1 ). Primarily high-molecular matter was removed by coagulation and...
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Effect of active ingredients to the activity of cementing compound with non-alkaline accelerator additive for sprayed concrete.
Závacký, Jakub ; Hela,, Vlastimil (referee) ; Hela, Rudolf (advisor)
The bachelor thesis deals with the problems of the sprayed concrete with the focus on usage of the active ingredients with non-alkaline accelerator additive. The theoretical part covers the current level of knowledge of how the active ingredients are used in the sprayed concrete and their influence on the process of hydration. In the experimental part the reactivity of cementing compound with non-alkaline accelerator on the basis of aluminium sulphate were compared in a laboratory when the active ingredients (such as slag, fly-ash and very fine limestone) were used. The cements CEM I 42,5 R, made by different producers were verified on the basis of the setting time and early strength gain using the Vicat needle to examine the mechanical properties after 6 and 24 hours.
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Optimization of the coagulation of water with higher concentration of aluminium
Tomášková, Hana ; Benešová, L.
High concentration of aluminium in water reservoirs can lead to higher concetration of residual aluminium in drinking water and then it can cause some health problems. For this reason is very important to optimalise the condition of water treatment, the main problem is inadvisable type and wrong dose of the coagulant and unsuitable intensity and duration of mixing. Optimalization with aluminium sulphate and ferric sulphate was made with raw water from two drinking water reservoirs Pilská and Lázská in Czech Republic
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