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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

Vliv organických látek produkovaných fytoplanktonem na koagulaci dalších znečišťujících příměsí přítomných v povrchových vodách / The impact of algal organic matter on coagulation of other impurities present in surface waters

Barešová, Magdalena January 2017 (has links)
Drinking water treatment is facing an adverse impact of algae especially when they extensively decay and release cellular organic matter (COM). As the character and consequently the removal efficacy of COM depends on the individual species, the thesis compares algal organic matter (AOM) derived from four common phytoplankton species: green alga Chlamydomonas geitleri, diatom Fragilaria crotonensis, and cyanobacteria Microcystis aeruginosa and Merismopedia tenuissima. To evaluate the differences between extracellular and cellular organic matter, we monitored the growth of those organisms and compared AOM obtained at different growth phases. As COM is not only difficult to coagulate, but also hinders the coagulation of other substances, the thesis investigates the effect of simultaneous coagulation of COM with other impurities present in surface waters: kaolin, humic substances (HS) or cyanobacterial cells of M. tenuissima. Coagulation behaviour was studied by the jar tests performed with single components and their mixtures with and without a coagulant (ferric or aluminium sulphate). Special emphasis was paid to proteinaceous COM of M. aeruginosa; to enhance the removability of proteinaceous matter we implemented pre-oxidation. Coagulation effectively removed turbidity (up to 99%) either of clay or...
12

Užití trombelastografie při hodnocení koagulace u žen s fyziologicky a patologicky probíhajícím těhotenstvím / The Use of Thromboelastography in Evaluation of Coagulation in Fenmales with Physiologial or Pathological Pregnancy

Polák, Ferdinand January 2011 (has links)
The Use of Thromboelastography in Evaluation of Coagulation in Females with Physiological or Pathological Pregnancy MUDr. Ferdinand Polák Abstract Introduction: The target of this study was to compare thromboelastography coagulation parameters in the following three groups: a) healthy pregnant women, b) healthy non-pregnant women and c) pregnant women with pathological pregnancy and also to compare it to reference limits for the common population. If appropriate, we would propose recommendations for new reference ranges for pregnant women in their third trimester. Materials and methods: Prospective observational study, comparing, by using thromboelastography, the blood samples of 60 healthy women in their third trimester of pregnancy (group GRAV) to the samples of the control group of 43 healthy non-pregnant fertile women (group NON-GRAV) and to the samples of 50 women with pathological pregnancy (preeclampsia, fetal death) in their third trimester (group PATOL). Selective percentiles were used to determine new reference limits. Results and conclusions: We found statistically significant differences between groups GRAV and NON-GRAV. Therefore, we established, based on our results, new thromboelastography reference limits for pregnant women. Coagulation changes during pathological pregnancy are less...
13

Vliv organických látek produkovaných fytoplanktonem na charakter agregátů tvořených koagulací/flokulací při úpravě vody / The influence of algal organic matter on the character of aggregates formed during the coagulation/flocculation process in drinking water treatment

Filipenská, Monika January 2017 (has links)
Tato práce se zabývá studiem vlivu kaolinitových ástic (reprezentujících látky tvo ící zákal vody) a peptidové/proteinové složky COM (Cellular Organic Matter) produkovaných sinicí Microcystis aeruginosa na velikost, strukturu a tvar tvo ených agregát v prom nných hydrodynamických podmínkách (gradientu rychlosti) p i úprav vody. Agregace probíhala v Taylor-Couettov reaktoru. Koagulace vybraných typ zne iš ujících p ím sí (kaolinitové ástice, COM peptidy/proteiny a jejich sm s) probíhala pomocí síranu hlinitého a síranu železitého. Vzniklé agregáty byly hodnoceny ve fázi homogenní velikosti (steady state) po 60 min míchání pomocí ukazatel : velikost (polom r) agregát , fraktální dimenze D2 a Dpf a velikostní distribuce. Bylo zjišt no, že velikost agregát je závislá na typu koagula ního inidla, typu koagulované p ím si a aplikovaném gradientu rychlosti. S rostoucím gradientem rychlosti se velikost agregát zmenšuje. Železité koagula ní inidlo produkuje v tší agregáty než hlinité koagula ní inidlo. Podle p ím si roste velikost agregát v po adí kaolinit < COM < kaolinit + COM. Struktura agregát se stává kompaktn jší s gradientem rychlosti. P i použití hlinitého koagula ního inidla vznikají ve srovnání s inidlem železitým kompaktn jší agregáty (mají vyšší hodnotu D2). Kompaktnost agregát klesá v po adí...
14

Optimalizace využití vratné vody na úpravně vody / Optimizing the use of sludge water on the water treatment plant

Hanušová, Veronika January 2018 (has links)
The first part of this diploma thesis deals with knowledge of chosen technological devices in water treatment plants gathered from Czech and foreign literature. The thesis continues by linking the information gathered to the water treatment plant in Švařec for which a plan to increase the sludge water volume reuse was researched and formed. Furthermore, financial assessment of this plan was completed.
15

Agregační reakce chitosanu využitelné při úpravě pitné vody. / Aggregation reactions of chitosan in drinking water treatment

Leskovjanová, Jana January 2008 (has links)
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.
16

Odstranění vybraných složek z vodního prostředí koagulací / Removal of Selected Components from the Aquatic Environment by Coagulation Process

Měřínská, Zuzana January 2011 (has links)
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.
17

Oxidace látek produkovaných sinicí Microcystis aeruginosa a její vliv na úpravu vody koagulací / Oxidation of compounds produced by cyanobacteria Microcystis aeruginosa and its impact on water treatment by coagulation

Štědrá, Karolína January 2021 (has links)
Due to eutrophication of aquatic environment, massive growth of algae and cyanobacteria occurs and the seasonal algal bloom is formed. Drinking water treatment plants have to deal with the increased amount of cells as well as organic compounds produced by algae and cyanobacteria (so-called AOM). Moreover, the presence of AOM causes a reduction in the efficiency of coagulation, which is an essential process in drinking water treatment. To increase coagulation efficiency, supportive methods, such as ozone oxidation, are added usually prior to coagulation. While many studies focused on the ozonation of algal and cyanobacterial cells, little is known about the effect of ozonation on AOM. This diploma thesis focused on the evaluation of the effect of ozonation in combination with coagulation on the removal of cellular organic compounds (COM) produced by cyanobacteria Microcystis aeruginosa. The effect of ozonation before or after coagulation on COM removal was investigated. The degradation of microcystins, which are naturally contained in the COM sample, was also monitored. Various ozone doses (1 - 10 mg/L) were tested at three pH values - 5, 7 and 9. Two coagulants were utilized - aluminium sulphate and ferric sulphate. Ozonation removed COM negligibly. However, eliminated microcystins, the degradation...
18

Interakce mezi proteiny a huminovými látkami při koagulaci / Interactions between proteins and humic substances during coagulation

Novotná, Kateřina January 2015 (has links)
This diploma thesis is focused on coagulation of humic substances (HS) and BSA (Bovine Serum Albumin) protein which was chosen as a representative of proteins contained in AOM (Algal Organic Matter). Additionally, possible interactions between these compounds were also investigated. It was found that the optimal dosage of coagulant is much higher for HS compared to BSA. The best removal of both HS and BSA was reached in slightly acidic pH range and it is attributed mainly to charge neutralization and adsorption mechanisms. The maximum removal rate was 70 % for humic substances and 80 % for BSA. The results show that BSA has a positive effect on coagulation of HS (resulting in a lower coagulant demand) and vice versa while BSA was removed more efficiently than HS. The existence of interactions between BSA and humic substantces during coagulation was demonstrated in certain pH ranges and it can occur even without the presence of coagulant. These interactions are highly dependent on pH that determines charge properties (and hence reactivity) of organic matters. Finally, the comparison of BSA and cyanobacterial proteins shows that their behavior during coagulation is similar. Consequently, BSA can be used as a model compound representing AOM proteins, especially their high molecular weight fraction....
19

Vliv parametrů sýřeniny na vybrané ekonomické ukazatele výroby sýrů s bílou plísní / Cheese curd parameters influence to selected economic factors of production of cheese with white fungus

Pavlíčková, Žaneta January 2008 (has links)
The theme of this diploma thesis is the monitoring of influences on economic aspect of the production of the blue cheese "Hermelín" in the company Pribina. The objective was to specify the dependencies of the deviations of the features of productive cow's milk and of cheese curd made from it and their economics impacts. For this purpose, the analyses of curd grain, whey and cheeses just formed were executed. The samples were taken and analyzed during the manufacturing of cheeses in the factory. Another goal was to try to design a quick operational method for measuring the firmness of curd grain, which is a factor theoretically dependent on renneting qualities of milk and indicating losses of valuable components from cheese curd to whey. The firmness of grain along with these losses may cause negative deviations from required standard of final products, especially at parametres needed for entry of cheeses on sale, such as total solids, weight or content of fat. Concerning productive pasteurize milk, the most attention was focused on the milk coagulation time and its influence on successive phases of manufacturing and on final product. Milk coagulation time is an essential technological quality of milk and it is participant on quantitative and qualitative production of cheese factory. It has been proved that milk coagulation time is notably affected by its titrating acidity, statistic analyse found this influence as very statistically significant (P
20

Upravitelnost povrchových vod / Treatibility of surface water

Fuks, Josef January 2013 (has links)
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.

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