National Repository of Grey Literature 26 records found  beginprevious17 - 26  jump to record: Search took 0.00 seconds. 
The use of alternative coagulants in water treatment
Hofmanová, Lucie ; Zelený, Zdeněk (referee) ; Kučera, Tomáš (advisor)
This bachelor's thesis deals with the use of alternative coagulants in water treatment. The first theoretical part mentions types of water treatment for the individual categories of raw water, related laws and ordinances. After that thesis describes the principle, mechanisms of coagulation and factors influencing the process. It analyses the jar test procedure performed within the experimental part of the bachelor's thesis. One chapter deals with polymers and metal coagulants based on aluminium and iron commonly used in water treatment. The chapter includes more detailed description of natural polymers moringa oleifera and chitosan. These two coagulating agents and aluminium sulfate were used in the second experimental part of the bachelor's thesis. Several sets of the jar test were performed in order to investigate the efficiency of chosen coagulants on the removal of turbidity from water. The thesis concludes with a comparison and evaluation of the results. Photos taken during the jar test can also be found at the end of the bachelor's thesis.
Drinking water contamination in water supply system
Černíková, Eva ; Třasoňová, Pavla (referee) ; Ručka, Jan (advisor)
The aim of this thesis is to consider the possible causes and consequences of contamination of drinking water in the water supply system. In the introduction are general information about the problems with water supply and some new approaches to water distribution system. In the next part there are described components of the water supply system and how they work. There are also described problems of drinking water contamination in water supply system. What are the mechanisms, what causes the turbidity and which microorganisms are the most common source of infections. In the final part there are described individual cases of drinking water contamination and what were the consequences. In the beginning there is a short form to every case which provides you a quick orientation in the problem.
Removal of Selected Components from the Aquatic Environment by Coagulation Process
Měřínská, Zuzana ; Márová, Ivana (referee) ; Janda, Václav (referee) ; Mergl, Václav (referee) ; Vávrová, Milada (advisor)
This thesis deals with coagulation treatment of surface water with content of humic matters, drug residues and turbidity. Commonly used coagulants (ferrous and aluminous sulphate) and natural biopolymer based on chitosan that not yet used in the Czech Republic had been studied. The aim of this work was to found the optimal application of chitosan in water treatment and comparison of its coagulation efficiency with standard inorganic coagulants. Theoretical part of the thesis contains occurrence, classification, composition, properties and importance of humic matters and drug residues and furthermore properties of chitosan and its using in water treatment. Experimental part summarizes the obtained results from the laboratory coagulation tests with inorganic coagulants and with chitosan leading to determination of its optimal dose. Other coagulation experiments were focused on finding the possibilities of combine the two coagulants (ferrous sulphate and chitosan) and to find their optimum doses and suitable ratio. The influence of pH on water treatment with using coagulation was also studied.
Discoloration events in the water-supply networks
Janča, Štěpán ; Kocůr, Pavel (referee) ; Ručka, Jan (advisor)
The aim of this thesis is to summarize the available knowledge on the occurrence and formation of turbidity in the water supply system and the design and application of methodology for measuring the potential occurrence of turbidity in the water supply. Problems of the current state of the quality of drinking water in public water supply systems, with a focus on the occurrence of cataract formation turbidity legislative change indicators of drinking water in the Czech Republic and abroad, and potential methods of measuring turbidity is discribed in the first part of the thesis. In the second part of the paper is a methodology for measuring the potential of turbidity in the water supply network. The methodology is applied in the case study Hrbová pressure zone, which is part of the distribution network of city Vsetin. The case study of the thesis is a statistical analysis and mathematical model of consumption of pressure zone Hrbová.
Treatibility of surface water
Fuks, Josef ; Palčík,, Jiří (referee) ; Kučera, Tomáš (advisor)
The aim of the master´s thesis is the topic of the treatability of surface water with the focus on the process of suspension formation. For this work I took water samples from five different places around the Brno Dam which has contended with water quality deterioration for a long period. With these water samples, the series of jar coagulation tests were done with the application of three different commonly used coagulants. In the theoretical part of the master´s thesis I deal with the composition and attributes of surface water and the technology of its treatment. Each process of treatment is briefly described here with the emphasis on the process of suspension formation. The experimental part of the master´s thesis summarizes and presents the results gained through the coagulation tests in the laboratory. I evaluate the influence of different parameters on final effectiveness of water treatment and I try to find an optimal amount of coagulant, pH and speed of fast or slow mixing. Finally I compare the suitability of each coagulant and the influence of the sampling site on the effectiveness of water treatment.
The efficiency of water treatment separation processes – model research
Vašalovská, Petra ; Slavíčková,, Kateřina (referee) ; Kučera, Tomáš (advisor)
Goal of this research was to recognize dissolved air flotation efficiency by the help of turbidity and UV absorbance removal for different conditions. As different conditions are meant the efficiency for different baffle position, different detention time in separation zone and checking results with adding chemicals compared to results without adding chemicals.
Hyaluronan ion complexes
Cimalová, Jana ; Sedlařík, Vladimír (referee) ; Pekař, Miloslav (advisor)
This diploma thesis is focused on the study of physical and chemical properties of hyaluronan and cationic surfactant. As the cationic surfactant Septonex was used. The influence of the environment on the system, the effect of molecular weight of hyaluronan, and its concentration was studied. Then, the study of the influence and the effects of concentration of Septonex on the interaction of hyaluronan-surfactant followed. Different methods of measurement were chosen to characterize these ionokomplexes. The critical micelle concentration of the surfactant itself was measured, and then also with the addition of hyaluronan by spectrofluorimetry with fluorescent probe pyren. It was found, that hyaluronan forms gel with Septonex. On this basis, gels were prepared for three different molecular weights of hyaluronan – 300 kDa, 806 kDa and 1697 kDa. Gels were prepared in a ratio of hyaluronan – surfactant 1:1. In gels prepared in this way, the influence of environmental water and 0.15 M NaCl was studied and it was found that at 0.15 M NaCl clear gels are formed. Selected samples of the gels were then measured with oscillatory testing and the rheological behavior of gels of Septonex was studied. As the last method the turbidimetric measurement was chosen, which characterized the turbidity point in the gradual addition of Septonex to sodium hyaluronate solution. Again, the effect of the molecular weight of hyaluronan and its concentration in two environments - water and 0.15 M NaCl was evaluated. It was found that 0,15 M NaCl suppresses formation of turbidity and formation of precipitates.
Monitoring of changes of drinking water quality during accumulation and distribution
Vaňková, Jitka ; Dolejš, Petr (referee) ; Mega, Jaroslav (advisor)
Theoretical part of the diploma thesis purveys information on drinking water and quality requirements, changes of drinking water quality during distribution and accumulation caused by disinfection, chemical processes, corrosion of constructional materials, incrusting solids, biofilms, nitrification of ammonia nitrogen, sediments in pipelines, elution of harmful matter. Attention was given to drinking water quality indicators which are associated with changes in drinking water distribution systems. In experimental part are studied changes of drinking water quality during distribution on the basis of selected drinking water quality indicators. There is specifically chemical oxygen demand, concentration of iron, manganese, ammonia ions, nitrites, nitrates, chloroform and chlorine. For periodical monitoring were selected suitable locality within the framework of Brno distribution system; for illustration were taken water samples from distribution systems of drinking water treatment plants Švařec, Vír, Štítary and Mostiště. For selected methods of analytical determination of above mentioned drinking water quality indicators are presented their characteristics. Obtained information on drinking water quality is mentioned in tabular and graphical form.
Removal of different species of phytoplankton by dissolved air flotation
Sukopová, Martina ; Mega, Jaroslav (referee) ; Dolejš, Petr (advisor)
The work evaluates the efficiency of dissolved air flotation (DAF) in removal of various kinds of phytoplankton. As absolutely necessary in the process of water treatment proved the agglomeration phase, or coagulation and floculation. This phase neutralizes the particles so that they can fasten air bubbles. The efficiency of this process depends on several variables, though: the kind of coagulant used, dose, coagulation pH, duration of floculation and its intensity, recycle ratio and the polymer use in coagulation. The particle size volume distribution and the volume of organic matter in raw water also have certain influence on phytoplankton removal. Dissolved air flotation is currently the most suitable method of phytoplankton removal. It can remove 93-98 % of blue-green algae and even 99-99.9 % of algae. The efficiency of flotation was also compared to sedimentation for the economic reason. In the process of water treatment, the sedimentation is now being replaced by flotation.
Influence of visibility in water column on predation pressure in predatory aquatic insects
PODHRADSKÁ, Eliška
The influence of abiotic factors on predation behaviour in predatory aquatic animals is reviewed. The most important factors are turbidity, light intensity and complexity of the environment. These abiotic factors are often combined with biotic factors. The second important part of thesis is the description of functional responses and influence of changes of visibility on individual components of predation behaviour. The review is complemented by laboratory experiments on two selected species of aquatic insects.

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