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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Čistící účinnosti netradičních filtračních materiálů / Cleaning effect of unconventional filtration materials

Fialová, Tereza January 2014 (has links)
Constructed wetlands and the soil filters are water treatment devices using the filter material that in most cases consists of natural river gravel, coarse sand or crushed stone. Master´s thesis deals with the research of cleaning effect of unconventional filtration materials, or more precisely with examination to load real waste water in a filtration column, to prove their ability to be used as an alternative medium that can ensure better cleaning effect. For the research work following metallurgical industry materials were used: fine slag and coarse slag 8-16 mm, materials from the natural character: zeolite, keramzit, a plastic material: PUR-foam. Also the traditional materials of fine gravel and coarse gravel were tested to compare the cleaning efficiency. Both the hydraulic and the cleaning efficiency of all above mentioned materials were tested. The examined hydraulic parameters are particularly porosity, hydraulic conductivity and suspended solids, turbidity and oxidation-reduction potential of both the inflow and outflow of the filter columns were determined. Accredited laboratory set the inflow and outflow of the filter columns BOD5, CODCr, total phosphorus, total nitrogen, nitrite, nitrate, ammonia and dissolved oxygen. By evaluating the results of the measurements it is determined which materials are suitable to be applied in the constructed wetlands and the soil filters. This filtration column was modeled by program HYDRUS and the result was compared with real results.
12

Studium mikrostruktury autoklávovaného pórobetonu s využitím druhotných surovin / Study of microstructure of autoclaved aerated concrete with using of secondary raw materials

Martanová, Jana January 2018 (has links)
Autoclaved aerated concrete is a used building material, especially for its thermal insulating properties. During autoclaving, an aerated concrete microstructure produces crystalline CSH phases, primarily tobermorite. The ingoing substances are calcium oxide and silica. In addition to commonly used raw materials, secondary raw materials rich in silicon dioxide can be used for production. The use of secondary raw materials gives the opportunity for the construction industry to be more environmentally friendly. Another benefit is the reduction of financial costs. The work explores the influence of individual secondary raw materials on the microstructure. High-temperature fly ash, fluid fly ash, cinder, ground glass and zeolite were used The raw materials were mixed with unalloyed lime at a molar ratio of calcium oxide to silicon dioxide of 0.73 and 1.0. Autoclaving capsules were used to synthesize tobermorite under laboratory conditions. Autoclave was performed at 170 °C and 190 °C with hydrothermal durations of 4, 8 and 16 hours. The most important influence on the microstructure was high-temperature fly ash, on the contrary, the greatest influence on the mechanical properties is attributed to the ground glass.

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