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Forest springs, a safe source of drinking water?
Mikuška, Pavel ; Alexa, Lukáš ; Kouřilová, S. ; Cigánková, Hana ; Křůmal, Kamil ; Itterheimová, Petra ; Kubáň, Petr ; Matoušek, Tomáš ; Barešová, Magdalena ; Pivokonský, Martin
Water from 25 forest springs was characterized for basic physical parameters and chemical and bacteriological composition. Chemical composition was mostly within limits for drinking water, but bacteriological results indicate faecal pollution of water in majority studied springs.
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Disinfection by-products in swimming pools and their effect on human health
Winterová, Sofie ; Načeradská, Jana (advisor) ; Barešová, Magdalena (referee)
Disinfection of swimming pool water is necessary for reducing the risk of disease transmission. Disinfection by-products form when chlorine reacts with organic matter contained in water. More than six hundred disinfection by-products have been found in swimming pools. Trihalomethanes, haloacetic acids, chloramines, halonitromethanes, haloacetonitriles and nitrosamines are among the most frequently occurring. Disinfection by-products may be toxic. The volatility of some of them causes their occurrence in the surrounding air and poses a risk not only for swimmers, but also for people in the vicinity who are not in direct contact with the water. DBPs enter human body by inhalation, absorption through the skin and ingestion. They have been linked to health problems such as skin and eye irritation, bladder cancer and respiratory diseases. Preventing their occurrence is not an easy task; a number of factors play a role in their genesis (the amount of organic matter, type and the amount of disinfection, the quality of source water, temperature, pH) and not all principles of their formation have been fully clarified yet. Further research on DBPs and their sufficient regulation are important steps to maintain chemical safety in swimming pools. Key words: disinfection by-products, swimming pool,...
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Influence of algal organic matter on coagulation of phytoplanktonic cells
Stránská, Štěpánka ; Pivokonský, Martin (advisor) ; Barešová, Magdalena (referee)
When algal or cyanobacterial populations increase in drinking water reservoirs, water treatment technologies have to cope not only with increased cell numbers but also with algal organic matter (AOM). The presence of cells and AOM in raw water causes some problems in the drinking water treatment process that can lead to the drinking water production of unsatisfactory quality. Residual algae cells and AOM can form toxic disinfection by-products (DBPs). Therefore, to maintain the cell integrity and prevent the release of AOM, it is essential for algae-polluted water treatment. This thesis examines the influence of AOM on coagulation of algal and cyanobacterial cells. The efficiency of coagulation is affected by various algae characteristics. The important have particularly the dependence of the coagulant dose on the cell surface area and the size and value of the surface charge of cells. It has been demonstrated that AOM can have not only negative but also positive influence on coagulation of cells. The presence of high concentrations particularly of low molecular weight (MW) AOM results in inhibition of coagulation. On the other hand, coagulation is improved by low concentration of high-MW AOM (particularly proteins) at approximately pH 4-6. Nowadays, for removal coagulated cells dissolved air...
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Application of Specific UV Absorbance (SUVA) for natural organic matter characterization
Vítková, Tereza ; Pivokonský, Martin (advisor) ; Barešová, Magdalena (referee)
This bachelor thesis focuses on the characterization of parameter of specific UV absorbance SUVA, which has currently been used during water treatment to estimate the reactivity of natural organic matter (NOM) to form byproducts of water disinfection. First, it was used to assess the potential formation of trihalogenmethane (THM) and it has been used instead of complicated measurement (Edzwald et al., 1985). Since then, its use has amended several times and currently the SUVA ability to predict the formation of individual classes of DBPs (Disinfection By-Products) on hygiene of drinking water has been studied most. Most of the studies examine in particular the formation of THMs and HAAS (haloacetic acids) which are strictly regulated because of their harmful properties for the environment and human health. Its questionless advantage is a quick and easy setting directly in the water treatment plants. However, the existing studies provide quite contradictory conclusions regarding its practical benefits to really predict how the water reacts with disinfectant and forms DBPs during the treatment. Based on the evaluation of the available literature SUVA seems to be more suitable for humic nature water which is similar with its physical properties. Vice versa, using SUVA for water containing AOM is...
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Haloacetic acids in drinking water
Poslušná, Markéta ; Načeradská, Jana (advisor) ; Barešová, Magdalena (referee)
Chlorination byproduct occur during water disinfection. These by-product are formed by the reactions between disinfectants and natural organic matter. High concentration od natural organic matter require higher doses of oxidizing agent, which increases the formation of chlorination byproduct. Chlorination byproduct pose health risk so they must be eliminated. This work researches focuses on the occurence of chlorination byproduct in several countries and evaluates the suitability of limits concentrations. The literary research has shown that there are currently not many studies about monitoring the occurence of chlorination byproduct. If these studies exist, they are often old and therefore i tis not possible to rationally assess the quality of drinking water in term of the occurrence of chlorination byproduct. Trichloracetic acid, dichloracetit acid and dibromacetic acid are mainly important from the health point of view. The are identifield as possible carcinogens. Higher concentrations of dichloracetic acid and trichloracetic acid were observed in most studies. The result of the studies show that the highest concentration of haloacetic acid were recorded in the cities of Cherepovets (Rusia), Athens (Greece), Warsaw (Poland) and Findland. Concentrations of haloacetic acid did not exceed the limit...
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The impact of algal organic matter on coagulation of other impurities present in surface waters
Barešová, Magdalena
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...
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The impact of algal organic matter on coagulation of other impurities present in surface waters
Barešová, Magdalena
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...
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Coagulation of different kinds of algal organic matter
Novotná, Kateřina ; Načeradská, Jana ; Barešová, Magdalena ; Janda, V. ; Pivokonský, Martin
This study focused on coagulation of different algal organic matter (AOM) fractions, especially on its non-proteinaceous fraction. It was derived from cellular organic matter of Chlorella vulgaris, a freshwater algae. Two different Al-based coagulants were employed, i.e. alum and pre-hydrolyzed polyaluminim chloride (PACl). The highest coagulation efficiency was obtained at pH around neutral (pH 7.1-7.5 for alum and pH 7.6-8.0 for PACl) at relatively high dosages of coagulant (8 and 10 mg·L-1 as Al for alum and PACl, resp.). However, the maximum removal reached under the optimized conditions was only approximately 20%. The coagulation behaviour and efficiency of non-proteinaceous matter greatly differ from AOM peptide-proteins, which is discussed in the study.
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Are cyanobacteria capable of enhancing drinking water treatment? Sci-fi or reality?
Barešová, Magdalena ; Načeradská, Jana ; Novotná, Kateřina ; Pivokonská, Lenka ; Pivokonský, Martin
Drinking water treatment struggles with cyanobacteria and algae mainly on a seasonal basis especially when they decay and release amounts of cellular organic matter (COM). As COM is not only difficult to be removed but it also impacts the removability of other impurities, this paper aims to evaluate the effect of COM derived from two common cyanobacterial species– Microcystis aeruginosa and Merismopedia tenuissima on coagulation of other naturally occurring particles and molecules present in surface waters: kaolin suspension, humin substances and cells of M. tenuissima. Our findings show that higher COM concentrations do not have to disrupt coagulation. When COM interacts with other impurities, it can even lower coagulant doses and increase both turbidity and humic matter removal efficiencies.
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The impact of algal organic matter on coagulation of other impurities present in surface waters
Barešová, Magdalena ; Pivokonský, Martin (advisor) ; Ambrožová, Jana (referee) ; Dolejš, Petr (referee)
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...
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