National Repository of Grey Literature 61 records found  beginprevious42 - 51next  jump to record: Search took 0.01 seconds. 
Improvement of Manganese Separation in Drinking Water Treatment
Bartoš, Ladislav ; Janda, Václav (referee) ; Hlaváč, Jaroslav (referee) ; Dolejš, Petr (advisor)
The submitted paper covers manganese comprehensively. The introduction provides an overview of its basic physical and chemical properties. Its compounds are discussed individually, including their preparation, production, and practical uses. Furthermore, a list of analytical methods in which manganese is involved in the form of its compounds as reagents is included. The same section includes an overview of analytical methods whereby manganese and its compounds are detected, primarily in water industry processes. Attention is paid to manganese as a non-negligible constituent of the various parts of the environment. The section on manganese’s biogenic properties is interesting from the viewpoint of its toxicity as well as its role as an important biogenic element, indispensable primarily for mammals. The subsequent chapters discuss the various methods which are suitable, under specific conditions, for separation in the treatment of surface and underground water aimed at producing drinking, process, or industrial water, where a minimal concentration of this metal is required. The impact of the physical/chemical conditions which influence the efficiency of separation in a manner ranging from non-negligible to principal, is discussed further on. Given the specifics of treatment of surface [and] underground water, the chapters provide more details on the processes suitable for specific types of matrix and specific conditions. Next chapters sum up many years of the author’s observations and experiences in the various parts of the water management system, from the raw water source to treatment to distribution, focusing on surface and underground water separately. Last chapter describes the construction of a water treatment plant model, its launch and calibration, and the tests focused on separating manganese by way of coagulation using aluminium and iron sulphate.
Influence of the various incubation time on the value of BOD
Debnárová, Andrea ; Dolejš, Petr (referee) ; Rozkošný, Miloš (advisor)
Biochemical Oxygen Demand (BOD) is commonly used for determining how fast biological organisms use up oxygen in a body of water. It is one of the essential methods used in water quality management and assessment. BOD could be considered as a quality level indicator of biologically treated water. This process is very time-dependent but most common period of incubation is five days - BOD(5). In this thesis different periods of incubation are compared - for BOD(5) with five days incubation period and BOD(2+5) with five days incubation period but also placed for two days to lowered temperature environment. These comparative tests were made for different types of water (surface water, waste water - water from mechanical level and biological level of treatment) For all kinds of determination of BOD the dilution method was used (ČSN EN 1899).
Optimization of chloramination based on raw water quality and operational conditions of a water treatment plant
Švec, Pavel ; Látal,, Milan (referee) ; Dolejš, Petr (advisor)
The most difficult part of water treatment is to ensure that water will be delivered to consumer in unchanged form and hygienic unexceptionable. To hygienic safety is using doses of chlor, whiches are deadly for organisms and inhibite their proliferation in pipeline. Modern way how to clear water from organism is called chloramination. By the help of ammonium salts chlor is released in sequence. So large single-shot doses of chlor aren´t necessary. Due the big dose was THM and another dangerous compounds formed.
Adsorption of natural organic matter (NOM) on granular activated carbon in the treatment of drinking water
Le Duc, Duy ; Mega, Jaroslav (referee) ; Dolejš, Petr (advisor)
In the first part of this thesis the methodic of lab trial was studied, which will be useful for studying adsorption of natural organic matter by activated carbon. As an optimal method of testing adsorption characters jar testing was chosen. Again as an indicator of organic contamination, it was decided to use permanganate chemical oxygen demand (in Czech CHSKMn) will be used. In the second part of this thesis the adsorption characters of eight types of granular activated carbon were studied. Those granular activated carbon came from two world produces, from company NORIT five type of granular activated carbon were tested: NORIT GAC 1020, NORIT PK 1-3, NORIT GAC 1240, NORIT ROW 0.8 SUPRA a TOD NORIT ROX 0.8 and from company Chemviron Carbon three types of granular activated carbon were tested: F100 FE11120A, F400 FE11210A a TL830 FE2028B. Batch kinetic tests of natural organic matter adsorption were conducted with all types of granular activated carbon at first. For description of sorption not only the batch kinetic tests and duration needed for setting equilibrium were observed, but also the process decreasing of concentration of natural organic matters to the value of equilibrium concentration known as adsorption equilibrium was followed.
Comparison of various modifications of coagulating tests
Vymazalová, Kamila ; Dolejš, Petr (referee) ; Mega, Jaroslav (advisor)
In the theoretical part of diploma thesis is elaboreted literary search relating to problems with using of various modifications of coagulation tests. The experimental part of diploma thesis is focused on comparison of three types of coagulation tests during treatment of model water with increased content of humic matter. Concretly was compared classic jar test, modified jar test and centrifugation test. As a coagulant was used ferric sulphate. The efficiency of treatment was tested under various conditions (temperature, time of fast mixing and intensity of slow mixing). Information capability of results was evalueted on the basis of absorbance by 254 nm and 387 nm, residual concentration of iron and dichromate value. Obtained results were numerically processed and they are presented in the form of tables and graphs.
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.
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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