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Development of the electrophoretic method for determination of phosphates and borates in cooling mixtures
Listakhava, Iryna ; Křížek, Tomáš (advisor) ; Kubíčková, Anna (referee)
In this diploma thesis, a method of routine analysis of commercial coolants was developed, focused on the simultaneous determination of inorganic anions - phosphates and borates - as corrosion inhibitors in fresh mixtures and the markers of recycling quality. The method was developed for the instrumental technique of capillary zone electrophoresis with indirect detection at 254 nm. The following were optimized: background electrolyte (its composition, concentration, pH), measured samples (coolant dilution, suitable internal standard) and measurement conditions (capillary length, sample dosing). The influence of the sample matrix on the measurement results, the robustness of the calibration line (or the agreement of the response with the actual analyte concentration) and also the repeatability of the method were tested. Optimizations and tests resulted in a method based on a standard addition with the following parameters: background electrolyte of pH = 11.50 containing sodium chromate at 10 mmol l-1 concentration and CTAB at 1 mmol l-1 concentration; dilution of the coolant sample 20-50×, addition of internal standard MES at 0,1 mmol l-1 concentration, electrokinetic sample injection at -5 kV for 10 s, capillary length 50.0 cm, inner diameter 75 μm. The repeatability of the method expressed as a...
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Analýza korozní odolnosti strojního zařízení v čistírnách odpadních vod
Dobrocká, Iva
The thesis deals with the analysis of corrosion resistance of machinery used in wastewater treatment plants. The theoretical part of the thesis deals with the composition of waste water in terms of corrosion aggressiveness and describes the corrosive en-vironment in the WWTP. Furthermore, the types of corrosion are characterized and the exposed machinery of the WWTP with the highest level of corrosion is determined. The experimental part of the work is devoted to the analysis of corrosion resistance of corrosion-resistant austenitic steels and structural non-alloyed steels with duplex zinc coating and acrylate paint. Furthermore, structural low-alloyed steels with chemical-heat treatment by nitriding and ferritic nitrocarburizing in gas and structural non-alloyed steel with duplex system of phosphate + epoxy coating and zinc + epoxy coating are analysed as a possible replacement for stainless steels. The steels with duplex system of zinc + acrylate coating used in practice show little corrosion resistance (the first signs of corrosion after 12 h and 24 h). some chemical-heat treated steels and steel with duplex sys-tem of zinc + epoxy coating achieved the same corrosion resistance as stainless steels (264 h test time) and can be used in technical practice.
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The influence of the surrounding landscape , fishery management , external and internal factors on water quality in ponds
Janáček, Štěpán ; Vach, Marek (advisor)
The thesis deals with the influences that affect water quality in the ponds . It focuses on selected factors which define water quality . These include e.g. the amount of dissolved oxygen in the water , ammonia, etc. To determine the change in water quality in a fish breeding tank, measured quality of water at the inlet of the tank and at its drain. I enter into the analysis and facts about the amount of fish stocking in ponds , basin shape , location of the pond in the countryside , farming in the watershed .
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