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The influence of flocculation conditions (global shear rate and time) on the shape and structure of formed aggregates and the efficiency of their separation by sedimentation and filtration
Pivokonský, Martin ; Vašatová, Petra ; Pivokonská, Lenka ; Petříček, Radim ; Filipenská, Monika
A summary research report on the influence of hydrodynamic conditions of flocculation (the intensity of mixing, residence time, etc.) on the property of the aggregates (size, shape, structure, etc.), that have a major impact on the separation steps (sedimentation, filtration) during water treatment. The report will be used by the water treatment plants with the technology of high intensity flocculation.
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Influence of organic matter on the character of aggregates formed during coagulation/flocculation process in dringing water treatment
Filipenská, Monika ; Pivokonská, Lenka ; Vašatová, Petra ; Pivokonský, Martin
Characteristics of aggregates (size, shape, density and porosity) affect separation efficiency. These characteristics come from properties of impurities (molecular weight and structure, charge density, affinity to water, etc.), coagulation parameters (pH, type and concentration of coagulants, etc.) and by physical conditions (shear rate and time of mixing). In this work, we describe relations between the size of aggregates and shear rate and moreover dependency on the characteristics of coagulated compounds. In order to understand dependency on compounds, flocs formed by kaolinite, Algal Organic Matter (AOM) and a mixture of the same were studied. There was found aggregates are bigger and more porous when AOM is present. The most striking result is that aggregates size changes in dependence on shear rate are not smooth in progress. A rapid change for the kaolinite-coagulant suspension and two rapid changes for the suspensions containing AOM were observed. These were attributed to various intermolecular interactions between floc components participating in coagulation at the different shear rate.
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The influence of algal organic matter on the character of aggregates formed during the coagulation/flocculation process in drinking water treatment
Filipenská, Monika ; Pivokonský, Martin (advisor) ; Janda, Václav (referee)
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...
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Use of polymers for drinking water treatment
Filipenská, Monika ; Benešová, Libuše (advisor) ; Pivokonský, Martin (referee)
Sources of drinking water are limited. It is clear that the need for quality drinking water is rising. Therefore, it is necessary to continuously improve methods to ensure sufficient quantity sanitary water. Coagulation-flocculation process is very often used in drinking water treatment. Except drinking water supply is coagulation used in waste treatment to wastewaters, landfill leachate and other contaminated water. Coagulation is mediated by coagulants - they have the ability to suppress the repulsive forces between the particles so that they can join in a contact in larger particles called flocs. Large and compact flocs are easily separated from the treated water. For this purpose have been used inorganic salt for long time. Most commonly salts of aluminum and iron. However, their effectiveness is not sufficient and their use also brings other disadvantages. By using aluminum compounds also discouraged, because aluminum may have link with Alzheimer's disease. Therefore, there were developed new coagulants based on organic polymers. These polykoagulants are significantly more efficient in cleaning. Their properties are easily influence by the content of their substances. For the water treatment used them much smaller dose than inorganic coagulants and so there is even less sludge and reduce...
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