La géosmine est un terpénoïde, provoquant un goût moisi-terreux associée à des flaveurs atypiques dans l'eau et le vin. Chez les bactéries, la voie de biosynthèse de la géosmine est bien caractérisée, mais peu de connaissance sont disponibles au sujet de sa biosynthèse chez les eucaryotes, en particulier dans les champignons filamenteux. L'origine de la géosmine dans la vigne est en grande partie attribuable à la présence de Penicillium expansum sur les raisins. Dans cette thèse, afin de mieux comprendre la voie de biosynthèse de la géosmine chez Penicillium expansum, nous avons décrit la caractérisation et l'analyse de "gpe1", un gène codant pour une cytochrome P450 monooxygénase impliquée dans la biosynthèse de la géosmine. Nous avons démontré que les deux fragments d'ADN: p450-1 et p450-2 appartiennent à un seul gène du cytochrome p450 (gpe1). La séquence d'acides aminés déduite de gpe1 a une identité moyenne de 40 % avec les enzymes PbP450-2 et P450-4 qui ont été trouvées impliquées respectivement dans la synthèse d'indole diterpène et dans la synthèse des gibbérellines. Les amplifications par PCR effectuée sur quatorze espèces de Penicillium ont montré que seules les espèces producteurices de la géosmine ont donné le même fragment de ~1,2 kb que gpe1. L'analyse du gène gpe1 nous a permis d'identifier la présence de certains domaines conservés de cytochromes P450 monooxygénases. Ensuite, la caractérisation fonctionnelle du gène gpe1 chez P. expansum M2230 a été décrite. Nous avons montré que les mutants de gpe1 ont perdus leur pouvoir de produire la géosmine alors que les révertants de gpe1 ont rétablis leur pouvoir de production. Enfin, nous avons démontré qu'une polykétide synthase putative et une putative NRPS sont présentes sur le côté droit du gène gpe1 proposant que le gène gpe1 pourrait être une partie d'un «Cluster» codant pour la biosynthèse de métabolites secondaires. / Geosmin is a terpenoid, an earthy-musty compound associated with off-flavors in water and wine. In bacteria, the biosynthesis pathway of geosmin is well characterized, but little is known about its biosynthesis in eukaryotes, especially in filamentous fungi. The origin of geosmin in grapevine is largely attributable to the presence of Penicillium expansum on grapes. In this thesis, we have described the characterization and analysis of "gpe1", a gene encoding a cytochrome P450 monooxygenase probably involved in the biosynthesis of geosmin in P. expansum M2230, in order to better understand of the biosynthesis pathway of geosmin in this species. We demonstrated that the two DNA fragments i.e. p450-1 and p450-2 belong to a single cytochrome p450 gene (gpe1). We showed that the deduced amino acid sequence of gpe1 has an average identity of 40 % with PbP450-2 and P450-4 enzymes which have been found involved in indole diterpene synthesis and in gibberellin synthesis respectively. Then, the results of PCRs performed on the fourteen Penicillium species showed that only Penicillium species which were producers of geosmin gave the same fragment of ~1.2 kb like gpe1. Analysis of the gpe1 gene enabled us to identify the presence of some conserved domains of cytochromes P450 monoxygenases in the amino acid sequence of gpe1. Then, the functional characterization of the gpe1 gene in P. expansum M2230 was described. We illustrated that the mutants of gpe1 lost their potential to produce geosmin whereas the reverse complements of gpe1 restored their potential to produce geosmin. Finally, we demonstrated that a putative polyketide synthase and a putative NRPS-like enzyme are present on the right side of the gpe1 gene suggesting that gpe1 gene might be the part of a gene cluster encoding the biosynthesis of secondary metabolites.

Nanofiltration (NF) membrane technology is effective for removal of natural organic matter (NOM) and Disinfection By-Product (DBP) precursors from treated surface water (Allgeier et al., 1995, Chellam et al., 2000, Smith et al., 2002). However, there is a need to control other micropollutants, such as compounds released from algal blooms. In this research, the feasibility of using NF for removal of cyanobacterial exudates was evaluated as a polishing process for conventionally treated surface water. Screening tests were conducted to compare the performance of four NF membranes, Filmtec's NF90 and NF270, and Hydranautics's LFC1 and NTR7450, for removal of NOM and cyanobacterial exudates. The source water for the experiments was derived from Lake Manatee (FL) following full scale treatment by enhanced coagulation and dual media filtration. Water samples were amended with low levels of three cyanobacterial exudates: microcystin-LR, geosmin and 2-Methylisoborneol (MIB). The rapid bench scale membrane test (RBSMT) protocol was used to test NF at four recoveries of 50%, 70%, 85% and 95%. Bulk organics (TOC and UV254) and inorganics (conductivity, total and calcium hardness) were monitored along with other operating parameters during the setting and recovery tests. Spike tests were performed by spiking microcystin-LR (9.5 to 12.0 micro g/L), geosmin (45 to 220 ng/L) and MIB (45 to 225 ng/L). Three NF membranes (NF90, NF270 and LFC1) were effective for over 90% rejection of TOC and associated disinfection by-product formation potential (DBPFP). Due to NF treatment, the bromide:TOC ratio increased resulting in a shift towards higher levels of brominated DBPFPs. Similarly, these three NF membranes (NF90, NF270 and LFC1) were effective for removal of microcystin-LR to below the World Health Organization (WHO) guideline of 1 micro g/L. Only two of the NF membranes tested (NF90 and LFC1), were capable of removing geosmin and MIB to levels below the taste and odor threshold. These membranes removed greater than 92% of the geosmin and MIB. Based on these bench scale tests, further testing of NF on a pilot scale is warranted.

Prior to full-scale implementation of process modifications at the Brantford WTP, a pilot-scale treatability study was conducted to investigate intermediate ozonation/AOP and to determine the most suitable granular media (anthracite, GAC, and Filtralite®) for deep-bed biological filtration. The primary objectives of this research were to provide insight into the destruction of natural and synthetic organics and assess ozonated and halogenated DBP formation. Ozone alone was unable to achieve the 1-log removal target for geosmin or MCPA, unless disinfection-level dosages were applied. No improvement was observed when adding hydrogen peroxide. A major obstacle to the implementation of ozonation in bromide-laden source waters is the formation of bromate. There is a direct correlation between ozone dose and bromate formation and by applying ozone dosages at disinfection levels, bromate is likely to exceed regulatory limits. However, adding hydrogen peroxide reduced the amount of bromate formed, and in most cases levels fell below regulatory limits. A linear correlation was established between bromate inhibition and increasing H2O2/O3 ratio at constant ozone dose. Amongst the three filtration media investigated, only GAC achieved 1-log removal for geosmin and MCPA. The superiority of GAC over anthracite and Filtralite® was attributed to its adsorption affinity. Filtralite® and anthracite media were both ineffective for MCPA removal due to its non-biodegradable nature under conventional water treatment conditions. At a 1 mg/L-ozone dose, GAC and Filtralite® filters achieved a 1-log geosmin removal. In contrast, a 1.44 mg/L ozone dose was required to meet this target with anthracite. The tandem of ozone followed by biological filtration was very effective for the control of distribution system TTHM production regardless of filter media, with levels well below current and anticipated provincial regulatory limits. The combination of intermediate ozonation followed by deep-bed biological filtration is well suited for treating Grand River water. Scale-up considerations include pairing the proper filter media to the size of the ozone generator. The best two treatment scenarios were: Option 1: select GAC media and size the ozone generator to produce a 1 mg/L dose. Option 2: select anthracite media and size the ozone generator to deliver a 2 mg/L dose.

The aim of this study was to investigate the efficacy of purification processes at the Rand Water Zuikerbosch treatment plant near Vereeniging. Raw water is abstracted via a canal and gravity pipeline from the Vaal Dam (in the upper Vaal River) and purified to ensure it meets the stringent standards set for drinkable water. The first step was to determine the ecological status of the raw water and it was done by measuring chemical, physical and biological variables as well as to identify and enumerate the different algal groups that occur in the raw water. The turbidity of the raw water was low but the phosphorous and ortho–phosphate levels were high. The Cyanophyceae (blue–green bacteria) especially Anabaena species were dominant in the raw water for the duration of the study. Potential problems such as relatively high alkalinity, chemical oxygen demand (COD) and total dissolved solids (TDS) as well as potentially hazardous chemicals such as cadmium and lead were observed in the raw water. The Zuikerbosch Water Treatment Plant (ZWTP) is a conventional water treatment plant which involves the following stages: coagulation, flocculation, sedimentation, sand filtration and chlorination. The use of pre–treatment chemicals ensures better water quality and effective removal of particles from the water. Only five of the variables (methylisoborneol (MIB); geosmin; chlorophyll–a; chlorophyll–665 and total organic carbon (TOC) were measured before filtration, after filtration and in the final water. Samples from the raw water, before and after filtration, as well as final water were collected weekly for a period of two years to measure the environmental variables as well as to do algal identification and enumeration. The purification processes at ZWTP were not able to remove MIB, geosmin, chlorophyll–a and TOC from the final water. Algal concentration was reduced but not totally removed by the purification processes. Although some variables were not totally removed by the purification processes, ZWTP produce potable water that complies with the Rand Water guidelines. / Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2011.

The aim of this study was to investigate the efficacy of purification processes at the Rand Water Zuikerbosch treatment plant near Vereeniging. Raw water is abstracted via a canal and gravity pipeline from the Vaal Dam (in the upper Vaal River) and purified to ensure it meets the stringent standards set for drinkable water. The first step was to determine the ecological status of the raw water and it was done by measuring chemical, physical and biological variables as well as to identify and enumerate the different algal groups that occur in the raw water. The turbidity of the raw water was low but the phosphorous and ortho–phosphate levels were high. The Cyanophyceae (blue–green bacteria) especially Anabaena species were dominant in the raw water for the duration of the study. Potential problems such as relatively high alkalinity, chemical oxygen demand (COD) and total dissolved solids (TDS) as well as potentially hazardous chemicals such as cadmium and lead were observed in the raw water. The Zuikerbosch Water Treatment Plant (ZWTP) is a conventional water treatment plant which involves the following stages: coagulation, flocculation, sedimentation, sand filtration and chlorination. The use of pre–treatment chemicals ensures better water quality and effective removal of particles from the water. Only five of the variables (methylisoborneol (MIB); geosmin; chlorophyll–a; chlorophyll–665 and total organic carbon (TOC) were measured before filtration, after filtration and in the final water. Samples from the raw water, before and after filtration, as well as final water were collected weekly for a period of two years to measure the environmental variables as well as to do algal identification and enumeration. The purification processes at ZWTP were not able to remove MIB, geosmin, chlorophyll–a and TOC from the final water. Algal concentration was reduced but not totally removed by the purification processes. Although some variables were not totally removed by the purification processes, ZWTP produce potable water that complies with the Rand Water guidelines. / Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2011.

No description available.

No description available.

Although utilities attempt to avoid offensive smelling compounds in consumer's drinking water, their efforts are often hampered by a lack of data or knowledge of the physical, chemical, and sensory properties of odorants. Many factors affect the ability of a consumer to detect odors, including: concentration, presence of chlorine/other odorants, temperature, and the individual's sensitivity. This research developed a simplified static-headspace technique to determine Henry's Law constants at multiple temperatures and then use these data to calculate the enthalpy of solution so that new Henry's Law constants can be calculated at any temperature using the van't Hoff Equation. The method was applied to three taste-and-odor compounds of moderate water solubility (about 100 mg/L). 2-Methylisoborneol (2-MIB) is a methylated monoterpene alcohol that is produced by actinomycetes and blue-green algae and has a musty odor that is detectable at 4-10 ng/L water. Geosmin, also produced by actinomycetes and blue-green algae, has a detectable earthy odor at 5-10 ng/L. trans-2, cis-6-Nonadienal is enzymatically synthesized from poly-unsaturated fatty acids by diatoms like Synura and has cucumber and fishy odors detectable at 10-40 ng/L levels. The new static headspace method uses standard glassware used in odor-analyses. 500 mL wide-mouth Erlenmeyer flasks were modified with septum sampling ports to measure vapor phase concentrations by SPME/GC-MS. Unitless Henry's Law constants were determined at multiple temperatures using the vapor and aqueous phase concentrations. From the Henry's Law constants, the enthalpies of reactions were calculated. For these compounds, the values for Henry's Law constants ranged from 0.002 to 0.02 for four temperatures between 20 to 45 °C with geosmin and 2-MIB having similar and higher values than for nonadienal. The constants increased with increasing temperature. The enthalpies of vaporization from the aqueous phase were determined to be in the range of 50-80 kJoule/mole. The experiments were repeated with fulvic acid added to the aqueous media at different concentrations. The Henry's Law constants were decreased with the presence of fulvic acid; however no correlation between the concentration of fulvic acid and the decrease was observed. The decrease in constants for 2-MIB and geosmin were very small compared to nonadienal. Finally the measured Henry's Law constants were used to predict gas phase concentrations of odorants for known aqueous concentrations of geosmin, 2-MIB, and nonadienal. The results were correlated to the human sensory data obtained from flavor profile analysis. The data demonstrated that as the gas phase concentration increased, the perceived odor intensity also increased, but only up to a certain point. The vapor phase concentration increased linearly as the aqueous phase concentration increased, but the FPA intensity increased at a lower rate and leveled-off. The increase in the FPA rating at 25ï °C was greater than at 45 °C although the vapor phase concentration was greater at 45 °C. For samples containing 400 and 600 ng/L geosmin, 400 and 600 ng/L, 2-MIB, 100 and 200 ng/L nonadienal, the increase in gas phase concentration did not increase the FPA ratings of the panelists. It was concluded that, utilities will be challenged to assess and treat high concentrations of geosmin, 2-MIB, and nonadienal. Sensory analysis will not be predictive of aqueous or vapor concentration at high levels and may be misleading if used to determine a treatment strategy. Chemical analyses, especially solid phase microextraction technique is very effective in measuring these compounds even at low ng/L levels. The temperature-related Henry's Law constants can be used to assess remediation systems, human exposure and sensory perception by predicting gas phase concentration in a variety of situations, such as showering and washing dishes. / Master of Science

As the bottled water trend continues to rise across the nation, drinking water utilities have become more concerned with ensuring consumer satisfaction of their product. Although public water supplies are safeguarded by regulations, aesthetically unappealing taste-and-odor problems have led consumers to search for alternative water sources, such as bottled water or tap water processed by point-of-use filters. Consequently, taste-and-odor monitoring has become important to the drinking water industry. Because many utilities use chlorine to disinfect the water, chlorine odor often masks other more subtle odors that may eventually cause consumer complaints. As treated water travels from the water treatment plant to the consumer, chlorine residual diminishes and may reveal a water's naturally less-pleasing odors. Consequently, odor monitoring at the water treatment plant, where chlorine concentrations are at a peak, may not identify potential displeasing smells. Proper evaluation of these odor-causing substances requires that the chlorine odor first be eliminated before evaluating any remaining odors. Dechlorinating agents can remove chlorine, but some will produce other unwanted odors or even remove certain odorous compounds. This research describes the efficiency of several of these agents (ascorbic acid, hydrogen peroxide, oxalic acid, sodium nitrite, and sodium thiosulfate) in dechlorinating chlorinated solutions of the earthy-smelling compound geosmin and musty-smelling MIB. Interfering odors in reusable containers pose another problem in drinking water odor analysis. The most common odor-analysis methods (TON and FPA) involve the use of glass flasks, which often either develop chalky odors or have persistent lingering odors from previous evaluations. Furthermore the glass flasks break easily and are difficult to clean. This research also evaluates the suitability of four types of disposable plastic containers for odor analyses. / Master of Science

<p>U radu je izvr&scaron;ena karakterizacija sirove (povr&scaron;inske) vode na lokalitetima: akumulaciono&nbsp;jezero, nizvodna deonica do izvori&scaron;ta namenjenog za vodosnabdevanje, na lokalitetu samog izvo-ri&scaron;ta i na ulazu u poluindustrijsko istraživačko postrojenje. Ustanovljene su sledeće karakteristike&nbsp;sirove vode: eutrofne karakteristike akumulacionog jezera u vremenskom periodu od kraja juna do&nbsp;sredine septembra meseca; fekalna zagađenost deonice od akumulacionog jezera do izvori&scaron;ta na-menjenog za vodosnabdevanje; veliki raspon temperature u toku godine (4-19&ordm;C); niske vrednosti&nbsp;mutnoće vode u najvećem delu godine uz povremen i kratkotrajan izrazit porast ovog parametra&nbsp;(&lt;1 NTU do &gt;90 NTU); promena sadržaja organskih materija u vodi (izraženih preko potro&scaron;nje ka-lijum-permanganata u kiseloj sredini i UV apsorbancije na 254 nm); izražen potencijal za formira-njem nusprodukata dezinfekcije (THM) u toku obilnih padavina.&nbsp;<br />Na poluindustrijskom istraživačkom postrojenju izvr&scaron;eno je ispitivanje različitih tehnolo&scaron;kih vari-janti pripreme vode za piće iz povr&scaron;inske vode namenjene vodosnabdevanju uz primenu savreme-nih tehnolo&scaron;kih re&scaron;enja i adekvatnog tretmana u slučaju ekscesa izazvanih ljudskom aktivno&scaron;ću.&nbsp;Primenjenim tretmanom vode procesima ozonizacije-koagulacije-flokulacije-sedimentacije-filtra-cije na poluindustrijskom istraživačkom postrojenju zadovoljena je primarna funkcija redukcije&nbsp;opterećenja vode pre odlaska na zavr&scaron;no bistrenje procesom filtracije. Ustanovljeni su najvažniji&nbsp;faktori uticaja na mutnoću vode nakon primenjenih procesa: vrsta koagulanta (najbolji efekti po-stignuti primenom Al₂(SO₄)_3&nbsp;i FeCl₃) i primenjena doza ozona (pozitivan, mikroflokulacioni efekat ozona postignut pri primenjenim dozama ozona od 0,5-1,0 mgO₃/l). Izračunato je da su pri primeni Al₂(SO₄)_3&nbsp;kao koagulacionog sredstva dvomedijumski filteri namenjeni zavr&scaron;nom bistrenju vode imali najduži filtracioni ciklus. Srednje vrednosti količine uklonjene mutnoće su 2,5- 3,5 puta veće u odnosu na ove vrednosti dobijene pri primeni ostalih koagulanata u fazi koagulacije vode. Značaj primenjenog procesa ozonizacije (doze ozona) uočen je i sa aspekta smanjenja sadržaja prekursora formiranja THM.</p><p>Ispitivanjem efekta predtretmana vode procesom ozonizacije, primenom vodonik-peroksida i ko-mercijalnog preparata koji u svom sastavu sadrži 25% H₂O_2&nbsp;+ 0,05% Ag u ozoniranu vodu u cilju&nbsp;redukcije broja mikroorganizama uočeni su pozitivni efekti na log_10&nbsp;inaktivacije pri dozama ozona&nbsp;&gt;0,5 mgO₃/l (u slučaju sporogenih sulfitoredukujućih klostridija) i vi&scaron;ih vrednosti odnosa H₂O₂/O_3&nbsp;i H₂O₂+Ag/O_3&nbsp;(u slučaju ukupnog broja aerobnih organotrofnih bakterija). Prednost primene preparata koji u svom sastavu sadrži 25% H₂O_2&nbsp;+ 0,05% Ag u ozoniranu vodu ogleda se u većem kapa-citetu eliminacije mikroorganizama i pri kraćem hidrauličkom vremenu zadržavanja vode.&nbsp;</p><p>Analizom frekvencije pojavljivanja jedinjenja koje prouzrokuje nepoželjan miris vode (geosmin)&nbsp;nakon primenjenih procesa ozonizacije-koagulacije-flokulacije-sedimentacije-filtracije ustanovljena je najmanja frekvencija pojavljivanja ovog jedinjenja (10% od ukupnog broja analiziranih uzo-raka) u vodi nakon procesa ozonizacije i njegova potpuna redukcija primenom koagulanta FeCl_3&nbsp;u&nbsp;fazi koagulacije vode.<br />Pri simulaciji ekscesnih situacija na poluindustrijskom istraživačkom postrojenju (doziranjem sintetičkih organskih jedinjenja pesticida i nafte) utvrđeno je da se primenom procesa ozonizacije-koagulacije-flokulacije-sedimentacije-filtracije uz dodatak AUP u fazi koagulacije vode postiže reduk-cija lindana u vodi za 97%, atrazina 99%, ukupnih ugljovodonika 91% i mineralnih ulja 89%.<br />Svi rezultati dobijeni u toku istraživanja na poluindustrijskom istraživačkom postrojenju posmatra-ni sa aspekta optimizacije tehnolo&scaron;kih uslova pripreme vode za piće i varijabilnog kvaliteta povr&scaron;in-ske vode ukazuju na prvom mestu na neophodnost primene procesa ozonizacije vode i pozitivan&nbsp;efekat unapređenih procesa oksidacije u fazi pripreme vode za dalju obradu, kao i na značaj primenjene vrste koagulanta i aktivnog uglja u prahu u fazi koagulacije i flokulacije vode.</p> / <p>The paper presents the characterisation of raw (surface) water at the following sites: accu-mulation lake, downstream section from the water supply well field at the very site of the well field&nbsp;and at the entrance into pilot plant. The following raw water characteristics have been determined:&nbsp;eutrophic properties of accumulation lake within the time frame from the end of June to the middle&nbsp;of September; faeces pollution of the section from the accumulation lake to the water supply well&nbsp;field; a wide range of temperature during the year (4-19&ordm;C); low values of water turbidity during the&nbsp;largest part of the year, with occasional and short-term emphasised growth &nbsp;of this parameter (&lt;1NTU to &gt;90 NTU); change in the content of natural organic matters in water (expressed through&nbsp;potassium permanganate consumption in acid environment and UV absorption at 254 nm); ex-pressed potential for disinfection by-products (THM) creation during high rainfall levels.</p><p>Study of different technological options for drinking water preparation from surface water desig-nated to water supply with application of the latest technological solutions and adequate treatment in cases of accidents caused by human activities has been carried out at the pilot plant.</p><p>The water treatment composed of ozonation-coagulation-flocculation-sedimentation-filtration applied at the pilot plant satisfied the primary function of reduction of water load prior to departure&nbsp;to the final clarification in filtration process. The most significant factors affecting water turbidity&nbsp;after the applied processes have been determined: type of coagulant (the best effects have been ob-tained by application of Al₂(SO₄)_3&nbsp;and FeCl₃) and the applied ozone dose (positive, micro-floccula-tion effect of ozone has been obtained with the applied ozone doses of 0,5-1,0 mgO₃/l). It has been&nbsp;calculated that two-media filters designated to final water clarification had the longest filtration cy-cle when Al₂(SО₄)_3&nbsp;was used&nbsp;as coagulation means. Medium values of quantity of the eliminated tur-bidity are 2,5-3,5 times higher in comparison to &nbsp;these values obtained when others coagulants were&nbsp;used in the water coagulation phase. The significance of the applied ozonization process (ozone&nbsp;dose) has also been found from the aspect of reduction of THM generation precursor contents.&nbsp;<br />Investigation of effects of water pre-treatment with ozonation process and application of hydrogen-peroxide and commercial preparation containing 25% H₂O_2&nbsp;+ 0,05% Ag in ozonized water aiming at&nbsp;reduction of micro-organisms count showed positive effects on log_10&nbsp;inactivation when &gt;0,5 mgO₃/l&nbsp;doses of ozone were used (in case of sulphito-reducing clostridia) and higher values of H₂O₂/O_3&nbsp;and&nbsp;H₂O₂+Ag/O_3&nbsp;ratio (in case of total aerobic organotrophic bacteria count). The advantage of appli-cation of the preparation containing 25% H₂O_2&nbsp;+ 0,05% Ag in ozonized water is reflected in higher&nbsp;microorganisms elimination capacity and shorter hydraulic retention time.&nbsp;<br />The analysis of occurrence frequency of compounds causing unpleasant water odour &nbsp;(geosmin) af-ter the applied ozonation-coagulation-flocculation-sedimentation-filtration processes showed that&nbsp;the lowest occurrence frequency for this compound (10% of the total number of the analysed sam-ples) in water after ozonisation process &nbsp;and its total reduction after the application of FeCl_3&nbsp;coagu-lant in water coagulation phase.<br />In simulation of accidents at pilot plant (dosing of synthetic organic compounds of pesticides and&nbsp;oil) it was found that reduction of lindane in water for 97%, atrazine for 99%, total hydrocarbons for&nbsp;91% and mineral oils for 89% is accomplished with application of the ozonation-coagulation-floccu-lation-sedimentation-filtration processes with addition of AUP in the phase of water coagulation.&nbsp;All the results that have been obtained during the researches at pilot plant have been considered&nbsp;from the aspect of optimisation of technological conditions of drinking water preparation and vari-able surface water quality point primarily to the necessity of application of water ozonization proc-ess and positive effect of the improved oxidation processes in the phase of water preparation for&nbsp;further processing as well as to the significance of the applied type of coagulant and active powder&nbsp;charcoal in water coagulation and flocculation phase.</p>