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Efekti odabranih unapredenih procesa oksidacije i koagulacije na sadržaj prirodnih organskih materija u vodi / The effects of selected advanced oxidation processes and coagulation on natural organic matter content in waterMolnar Jazić Jelena 10 October 2011 (has links)
<p>Cilj ovog rada bio je da se u laboratorijskim uslovima ispitaju efekti odabranih<br />unapredenih procesa oksidacije (Fenton proces, ozonizacija, TiO2-katalizovana ozonizacija,<br />perokson proces i TiO2-katalizovan perokson proces) i koagulacije na sadržaj i strukturu<br />prirodnih organskih materija u vodi, kao prekursora dezinfekcionih nusprodukata hlora.<br />Karaterizacija POM frakcionisanjem pre i nakon navedenih oksidacionih tretmana i<br />koagulacije izvršena je u cilju ispitivanja mehanizama oksidacije i uklanjanja POM, kao i<br />utvrdivanja promene reaktivnosti prekursorskog materijla DBP (trihalometana i halosircetnih<br />kiselina, kao najviše zastupljenih DBP, i haloacetonitrila, hlorpikrina i haloketona, kao<br />nedovoljno istraženih, visoko prioritetnih „DBP u razvoju“).<br />Analizom hemijskih karakteristika prirodnog matriksa utvrdeno je da voda sadrži<br />visoke koncentracije prirodnih organskih materija (DOC sirove iznosi 9,92±0,87 mg/L) uz<br />dominaciju materija hidrofobnog karaktera (14% huminskih i 65% fulvinskih kiselina). U<br />slucaju sintetickog matriksa (sadržaj DOC 11,2±0,37 mg/L) zastupljena je samo frakcija<br />huminske kiseline, te je iz tog razloga sinteticki matriks znatno hidrofobniji u odnosu na<br />prirodni. Veci stepen hidrofobnosti sintetickog matriksa u poredenju sa prirodnim matriksom,<br />rezultovao je i vecim sadržajem prekursora najzastupljenijih dezinfekcionih nusprodukata<br />hlora, THM i HAA. Vrednosti za PFTHM iznose 438±88,2 μg/L za prirodni matriks,<br />odnosno 3646±41,3 μg/L za sinteticki matriks, dok PFHAA prirodnog matriksa iznosi<br />339±68,9 μg/L, odnosno 559±20,5 μg/L za sinteticki matriks. Sadržaj HAN, CP i HK je<br />znatno niži u poredenju sa prekursorima THM i HAA. PFHAN iznosi 3,65 μg/L za prirodni,<br />odn. 7,98 μg/L za sinteticki matriks, dok prekursori CP nisu detektovani. Prekursori HK su<br />zastupljeni samo u strukturi POM prirodnog matriksa i PFHK iznosi 46,9±5,08 μg/L.<br />Hidrofoban materijal, kao dominantan u strukturi POM ispitivanih matriksa, je ujedno i<br />osnovni prekursorski materijal THM i HAA, dok su prekursori haloacetonitrila i haloketona u<br />navecoj meri zastupljeni u hidrofilnoj frakciji.<br />Ispitivanjem uticaja Fenton procesa na sadržaj POM, pri optimalnim reakcionim<br />uslovima (pH 5, reakciono vreme od 15 min. i brzina mešanja 30 o/min), postignuto je u<br />zavisnosti od primenjene doze Fe2+, molarnog odnosa Fe2+ i H2O2 i matriksa 80-95%<br />smanjenja saržaja DOC, 70-99% PFTHM, 37-92% PFHAA. Kao posledica uklanjanja POM<br />oksidaciojom i koagulacijom, zabeležene su blage fluktuacije u sadržaju prekursora HAN, CP<br />i HK.<br />Ispitivanjem uticaja ozonizacije u vodi pri razlicitim pH na sadržaj i strukturu POM<br />utvrdeno je da je ozonizacija u baznoj sredini efikasnija za uklanjanje POM u odnosu na<br />ozonizaciju u kiseloj sredini. Katalizovanje procesa ozonizacije primenom TiO2 u vodi<br />razlicitim pH unapreduje smanjenje sadržaja kako ukupnih organskih materija, tako i<br />specificnih prekursora DBP u poredenju sa ozonizacijom. Najefikasnije smanjenje sadržaja<br />POM postignuto je TiO2-O3 procesa u baznoj sredini primenom 3,0 mg O3/mg DOC i 1,0 mg<br />TiO2/L (30% DOC, 92-100% PFTHM, PFHAA, PFHAN i PFHK). TiO2-O3 proces pri svim<br />pH vrednostima produkuje manji sadržaj CP u odnosu na ozonizaciju. Veca efikasnost<br />primenjenih procesa u smanjenju sadržaja POM sintetickog matriksa u odnosu na prirodni<br />ukazuju da je frakcija huminske kiseline podložnija oksidacionom tretmanu u odnosu na<br />fulvinsku, kao dominantnu frakciju POM prirodnog matriksa. Kada je u pitanju mehanizam<br />oksidacije POM ispitivanih matriksa, primenom ozonizacije i TiO2-O3 procesa, pri svim pH<br />postignuta je potpuna oksidacija frakcije huminske kiseline do fulvinske kiseline i hidrofilnih<br />jedinjenja. U slucaju ozonizacije, sa povecanjem pH vrednosti sredine, usled povecane<br />produkcije hidroksil radikala iz ozona, povecao se i udeo odnosno sadržaj DOC u hidrofilnoj<br />frakciji ozonirane vode (86%-90%). Raspodela DOC nakon TiO2-O3 procesa pri svim pH<br />vrednostima je oko 70% i 50% u hidrofilnoj frakciji prirodnog i sintetickog matriksa, redom.<br />Frakcija koja se dominantno formira nakon navedenih oksidacionih tretmana je hidrofilna nekisela<br />frakcija. Frakcionisanjem POM nakon oksidacionih tretmana je utvrdeno da su<br />prekursori THM i HAA kako hidrofobne aromaticne strukture, tako i hidrofilna polarna<br />jedinjenja, dok je najreaktivniji prekursorski materijal HAN, CP i HK sadržan u hidrofilnoj<br />frakciji POM.<br />Uvodenjem H2O2 u proces ozonizacije (O3/H2O2 i iO2-O3/H2O2) u slabo baznoj<br />sredini (pH 7-7,5) postignut je još veci stepen oksidacije POM i povecanje udela hidrofilnih<br />struktura (oko 88%) ispitivanih matriksa u odnosu na ozonizaciju i iO2-O3 (oko 70%),<br />primenom 3,0 mg O3/mg DOC; O3:H2O2=1:1 i 1,0 mg iO2/L. Povecanje sadržaja prekursora<br />THM i HAA samo u slucaju prirodnog amtriksa posledica je povecanja reaktivnosti frakcije<br />fulvinske kiseline nakon O3/H2O2 i iO2-O3/H2O2 procesa, u kojoj su ujedno i prekursori HK<br />najzastupljeniji. Najveci sadržaj azotnih DBP (HAN i CP) sadrži hidrofilna frakcija POM.<br />Ispitivanjem kombinovanih procesa ozonizacije i TiO2-O3 i koagulacije utvrdeno je da<br />oksidacioni tretmani imaju pozitivne efekte u uklanjaju POM koagulacijom. Maksimalna<br />efikasnost smanjenja sadržaja DOC od 32% postignuto je primenom 3,0 mg O3/mg DOC i<br />200 mg FeCl3/L, dok su nešto niže doze ozona pogodne za uklanjanje prekursora DBP (80-<br />89% PFTHM, PFHAA, PFHAN i PFHK, primenom 0,7-1,0 mg O3/mg DOC i 200 mg<br />FeCl3/L). Prekursori CP koji se formiraju ozonizacijom zaostaju u vodi nakon koagulacije.<br />Rezultati dobijeni tokom istraživanja ukazuju da se primenom razlicitih oksidacionih i<br />unapredenih oksidacionih procesa može smanjiti sadržaj POM i prekursora DBP do<br />odredenog stepena. Kao najefikasniji u uklanjaju kako ukupnih organskih materija, tako i<br />specificih prekursora DBP se pokazao Fenton proces. Kada su u pitanju unapredeni procesi<br />oksidacije zasnovani na primeni ozona, uvodenje katalizatora ili H2O2 kao oksidanta u proces<br />ozonizacije, kao i odabir optimalne pH vrednosti procesa može unaprediti oksidabilnost<br />organskih molekula. Pri tom, poznavanje mehanizama oksidacije POM iz razlicitih izvora<br />primenom ozona i/ili hidroksil radikala, kao i mehanizma uklanjanja POM koagulacijom<br />može se primeniti za odabir i optimizovanje odgovarajuceg procesa u tretmanu vode za pice,<br />a u zavisnosti od kvaliteta sirove vode.</p> / <p>The aim of this work was to examine under laboratory conditions the effects of<br />certain advanced oxidation processes (Fenton process, ozonation, TiO2-catalyzed ozonation, peroxone process and TiO2-catalyzed peroxone process) and coagulation on the content, structure and role of natural organic matter in water as the precursors of chlorine disinfection byproducts. The NOM was characterized by fractionation before and after these oxidation treatments and coagulation, in order to investigate NOM oxidation mechanisms and identify the changes in the reactivity of DBP precursor material (trihalomethanes and haloacetic acids, as the most abundant DBP, and haloacetonitriles, chloropicrin and haloketones, as underresearched, high priority “emerging DBP”). Through analysis of the chemical characteristics of the natural matrix, it was found that the water contains high concentrations of natural organic matter (raw water DOC was 9.92 ± 0.87 mg/L) dominated by substances with a hydrophobic character (14% humic and 65% fulvic acids). The synthetic matrix studied (DOC content of 11.2 ± 0.37 mg/L) contained only the humic acid fraction, and was therefore significantly more hydrophobic compared to the natural one. The greater degree of hydrophobicity in the synthetic matrix relative to the natural matrix resulted in a higher content of precursors of the most frequent chlorine disinfection byproducts, THM and HAA. The THMFP of the natural matrix was 438±88.2 mg/L, compared to 3646±41.3 mg/L for the synthetic matrix, while the HAAFP of the natural matrix was 339±68.9 mg/L, compared to 559±20.5 mg/L for the synthetic matrix. The contents of HAN, CP, and HK precursors were much lower than the THM and HAA precursors. HANFP were 3.65 mg/L for natural, and 7.98 mg/L for the synthetic matrix, whilst CP precursors were not detected. HK precursors were present only in the structure of the natural NOM matrix, with a HKFP of 46.9±5.08 mg/L. Hydrophobic material, as the dominant structure in the investigated NOM matrix, is the basic precursor material of THM and HAA, while the precursors of haloacetonitriles and haloketones are represented mostly in the hydrophilic fraction.<span style="font-size: 12px;">Whilst examining the influence of the Fenton process on the NOM content, under </span><span style="font-size: 12px;">optimal reaction conditions (pH 5, reaction time of 15 min and stirring speed of 30 rpm), </span><span style="font-size: 12px;">depending upon the applied dose of Fe2+, the molar ratio of Fe2+ and H2O2, and the matrix, </span><span style="font-size: 12px;">reductions in the DOC content of 80-95%, in the THMFP of 70-99%, and in the HAAFP of </span><span style="font-size: 12px;">37-92%, were achieved. As a result of removing NOM by oxidation and coagulation, mild </span><span style="font-size: 12px;">fluctuations in the contents of HAN, CP and HK precursors were recorded. </span><span style="font-size: 12px;">The investigation into the effects of ozonation at different pH levels on the content </span><span style="font-size: 12px;">and structure of NOM has shown that ozonation under alkaline conditions is more effective at </span><span style="font-size: 12px;">removing NOM than ozonation under acidic conditions. Catalyzing the ozonation process </span><span style="font-size: 12px;">using TiO2 in water with different pH promotes the reduction of both total organic matter and </span><span style="font-size: 12px;">specific DBP precursors in comparison with ozonation alone. The most effective NOM </span><span style="font-size: 12px;">reduction was achieved using the TiO2-O3 process in alkaline conditions using 3.0 mg O3/mg </span><span style="font-size: 12px;">DOC and 1.0 mg TiO2/L (30% DOC, 92-100% THMFP, HAAFP, HANFP and HKFP). The </span><span style="font-size: 12px;">TiO2-O3 process produces lower amounts of CP at all pH values, relative to ozonation. The </span><span style="font-size: 12px;">applied processes showed increased efficacy in reducing the NOM content of the synthetic </span><span style="font-size: 12px;">matrix compared with the natural matrix, which shows that the humic acids fraction is more </span><span style="font-size: 12px;">susceptible to oxidation treatments than the fulvic acids which are the dominant faction of the </span><span style="font-size: 12px;">natural NOM matrix. Regarding the NOM oxidation mechanism in the investigated matrices, </span><span style="font-size: 12px;">using ozonation and the TiO2-O3 process, complete oxidation of the humic acid fraction to </span><span style="font-size: 12px;">fulvic acids and hydrophilic compounds was achieved at all pH levels. In the case of </span><span style="font-size: 12px;">ozonation, increasing the pH in the matrix lead to an increase in hydroxyl radicals production </span><span style="font-size: 12px;">from ozone, and the proportion or content of DOC in the hydrophilic fraction of ozonated </span><span style="font-size: 12px;">water (86%-90%) increased. The distribution of DOC after the TiO2-O3 process at all pH </span><span style="font-size: 12px;">values was about 70% and 50% in the hydrophilic fraction of the natural and synthetic </span><span style="font-size: 12px;">matrices, respectively. The dominant fraction formed after the oxidation treatments was the </span><span style="font-size: 12px;">hydrophilic non-acid fraction. By NOM fractionation after the oxidation treatments, it was </span><span style="font-size: 12px;">shown that the THM and HAA precursors are hydrophobic aromatic structures and </span><span style="font-size: 12px;">hydrophilic polar compounds, whilst the most reactive precursor materials for HAN, CP and </span><span style="font-size: 12px;">HC are contained in the hydrophilic NOM fraction. </span><span style="font-size: 12px;">Introducing H2O2 into the ozonation process (O3/H2O2 and iO2-O3/H2O2) in weak </span><span style="font-size: 12px;">basic conditions (pH 7 to 7.5) enhances further the degree of NOM oxidation and increases </span><span style="font-size: 12px;">the proportion of hydrophilic structures (88%) in the examined matrices in comparison to </span><span style="font-size: 12px;">ozonation and iO2-O3 (about 70%), using 3.0 mg O3/mg DOC; O3:H2O2=1:1 and 1.0 mg </span><span style="font-size: 12px;">iO2/L. An increase in the THM and HAA precursor contents occurred in the case of the </span><span style="font-size: 12px;">natural matrix as a result of the increased reactivity of the fulvic acid fraction after the </span><span style="font-size: 12px;">O3/H2O2 and iO2-O3/H2O2 processes, and HK precursors were also present. The highest </span><span style="font-size: 12px;">content of nitrogen DBP (HAN and CP) was found in the hydrophilic NOM fraction. </span><span style="font-size: 12px;">By examination of the combined processes of ozonation, TiO2-O3 and coagulation, it was </span><span style="font-size: 12px;">shown that oxidative treatments have a positive effect on NOM removal by coagulation. A </span><span style="font-size: 12px;">maximum efficacy in reducing DOC by 32% was achieved with 3.0 mg O3/mg DOC and </span><span style="font-size: 12px;">200 mg FeCl3/L, whereas slightly lower ozone doses are suitable for the removal of DBP </span><span style="font-size: 12px;">precursors (80-89% THMFP, HAAFP, HANFP and HKFP, using 0.7-1.0 mg O3/mg DOC </span><span style="font-size: 12px;">and 200 mg FeCl3/L). CP precursors which are formed during ozonation remain in the water </span><span style="font-size: 12px;">after coagulation. </span><span style="font-size: 12px;">The results obtained during this investigation show that the application of different oxidation </span><span style="font-size: 12px;">and enhanced oxidation processes can reduce the contents of NOM and DBP precursors to </span><span style="font-size: 12px;">some degree. The most effective process at removing both total organic matter and specific </span><span style="font-size: 12px;">DBP precursors proved to be the Fenton process. With respect to enhanced oxidation </span><span style="font-size: 12px;">processes based upon the use of ozone, by introducing catalysts or H2O2 as an oxidant in the </span><span style="font-size: 12px;">ozonation process and by selecting the optimum pH for the process, the oxidizability of </span><span style="font-size: 12px;">organic molecules can be improved. In addition, knowledge of the NOM oxidation </span><span style="font-size: 12px;">mechanisms from different sources using ozone and / or hydroxyl radicals, as well as the </span><span style="font-size: 12px;">mechanism of NOM removal by coagulation, can be used to select and optimize the most </span><span style="font-size: 12px;">appropriate process in drinking water treatment, depending upon the quality of the raw water.</span></p>
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Uticaj oksidacionih procesa na bazi ozona, vodonik-peroksida i UV zračenja na sadržaj i reaktivnost prirodnih organskih materija u vodi / The influence of oxidation processes based on ozone, hydrogen peroxide and UV irradiation on the content and reactivity of natural organic matter in waterPetronijević Mirjana 28 August 2019 (has links)
<p>Cilj istraživanja u okviru ove doktorske disertacije je utvrđivanje efekata različitih<br />oksidacionih procesa na bazi ozona, vodonik-peroksida i UV zračenja na sadržaj i reaktivnost prirodnih organskih materija (POM) u različitim vodenim matriksima. Ispitivanja su sprovedena na a) podzemnoj vodi sa teritorije Kikinde i Temerina (prirodni matriks) i b) sintetičkom vodenom matriksu (rastvoru komercijalno dostupne huminske kiseline), koji se među sobom razlikuju po sastavu i strukturi prisutne POM i sadržaju bromida. Za oksidacioni proces (ozonizacija, UV fotoliza, oksidacija sa H<sub> 2</sub>O<sub>2</sub>, kombinovani O <sub>3 </sub>/UV proces i kombinovani H <sub>2</sub>O<sub>2</sub><br />/UV proces) pojedinačno ispitan je uticaj različitih doza oksidanata i reakcionih uslova.Posebna pažnja posvećena je ispitivanju uticaja navedenih tretmana na<br />formiranje neorganskog bromata, kao i uticaja na sadržaj prekursora dezinfekcionih nusproizvoda nakon hlorisanja (THM, HAA, HAN, HK i CP).<br />Analiza hemijskih parametara sintetičkog matriksa (5,44±0,30 mg C/l; 0,255±0,015 cm<sup> -1</sup> ; 4,68±0,41 lm<sup> -1</sup> mg <sup>-1 </sup>) pokazuje da u njemu preovladavaju huminnske materije visoke hidrofobnosti. Visok sadržaj POM pretežno hidrofobnog karaktera je zabeležen i u vodi iz Kikinde (5,170,72 mg C/l; 0,2010,001 cm <span id="cke_bm_192S" style="display: none;"> </span><span id="cke_bm_190S" style="display: none;"> </span><sup>-1</sup><span id="cke_bm_192E" style="display: none;"> </span><span id="cke_bm_190E" style="display: none;"> </span> ; 3,88±0,70 lm<span id="cke_bm_193S" style="display: none;"> </span><sup> -1</sup><span id="cke_bm_193E" style="display: none;"> </span> mg<sup> -1</sup> ), dok je sadrža<span id="cke_bm_194E" style="display: none;"> </span>j POM u sirovoj vodi iz Temerina (2,060,38 mg C/l; 0,0500,001 cm<span id="cke_bm_203S" style="display: none;"> </span><span id="cke_bm_201S" style="display: none;"> </span><sup> -1</sup><span id="cke_bm_203E" style="display: none;"> </span><span id="cke_bm_201E" style="display: none;"> </span> ; 2,43±0,21 lm <span id="cke_bm_204S" style="display: none;"> </span><sup>-1</sup><span id="cke_bm_204E" style="display: none;"> </span> mg <sup>-1</sup><span id="cke_bm_205E" style="display: none;"> </span><span id="cke_bm_202E" style="display: none;"> </span><span id="cke_bm_191E" style="display: none;"> </span><br />) značajno niži i preovladavaju POM hidrofilnog karaktera. Veći stepen hidrofobnosti sintetičkog matriksa u poređenju sa prirodnim matriksima, rezultovao je i većom reaktivnosti organske materije sa hlorom, što se može zaključiti na<br />osnovu visokih vrednosti PFDBP nakon hlorisanja. Vrednost PFTHM u sintetičkom matriksu iznosi 544±85,9 µg/l, dok je PFTHM u kikindskoj i temerinskoj sirovoj vodi znatno niži (279±32,3 i 180±44,0 µg/l, respektivno). Vrednost PFHAA u sintetičkom matriksu iznosi 484±77,5 µg/l, dok je PFHAA u kikindskoj 244±11,1 µg/l i u temerinskoj vodi 165±32,5 µg/l. Sadržaj HK (8,05±3,63 µg/l sintetički matriks; 14,91,38 µg/l Kikinda; 7,400,25 µg/l Temerin) je znatno niži u poređenju sa prekursorima THM i HAA, dok prekursori HAN i hlorpikrina nisu detektovani u sirovoj vodi. Nusproizvodi koji se dominantno formiraju u svim ispitivanim vodenim matriksima su hlorovani THM i HAA, dok se bromovani DBPformiraju u znatno nižim koncentracijama. Zastupljenost bromovanih DBP u temerinskoj vodi<br />je znatno veći u poređenju sa vodom iz Kikinde, kao rezultat prisustva veće koncentracije bromida u sirovoj vodi (0,05±0,01 mg Br -/l Temerin; 0,03±0,01 mg Br<br />-/l Kikinda). Ispitivanjem uticaja oksidacionih procesa (UV fotolize, ozonizacije, oksidacije vodonik-peroksidom) na sadržaj i reaktivnost POM u ispitivanim vodenim matriksima utvrđeno je da tretman vode UV zračenjem i vodonik-peroksidom, kada se primenjuju kao samostalan tretman, ne pokazuju značajnu efikasnost u smanjenju sadržaja POM.Tretman vode ozonom se pokazao kao veoma efikasan u uklanjanju POM i u smanjenju sadržaja prekursora DBP kod svih ispitivanih vodenih matriksa, kao rezultat smanjenja reaktivnosti POM ka formiranju ovih DBP. Smanjenje sadržaja POM u vodi tokom tretmana raste sa povećanjem primenjene doze ozona, pri čemu se najbolji rezultati postižu pri najvećoj primenjenoj dozi od 3,0 mg O 3/mg DOC (do 32% DOC, 92% UV254 sintetički matriks; do 17% DOC, 76% UV 254 Kikinda; do 15% DOC i 66% UV254 Temerin). U sintetičkom matriksu najveće smanjenje PFTHM (za 76%) i PFHAA (za 80%) u odnosu na sadržaj u sirovoj vodi se postiže pri dozi od 1,0 mg O<sub>3 </sub>/mg DOC. Najveće smanjenje PFTHM (za 38%)<br />i PFHAA (za 42%) u vodi iz Kikinde postiže se pri dozi od 3,0 mg O <sub>3 </sub>/mg DOC. U vodi iz Temerina najveće smanjenje PFTHM (za 27%) je pri dozi od 3,0 mg O <sub>3</sub> /mg DOC, dok se za smnjenje PFHAA (za 54%) najbolje pokazala doza od 1,0 mg O<br />3 /mg DOC. Sadržaj prekursora HK i HAN (temerinska voda) je veoma nizak nakon tretmana. Tretman vode ozonom vodi ka formiranju DBP sa više supstituisanih atoma broma, dok u vodama sa srednjim sadržajem bromida (50 µg Br -/l) dovodi do formiranja bromata. Kombinacijom ozonizacije sa UV zračenjem se značajno može pospešiti efiksnost uklanjanja POM postignuta primenom samostalne ozonizacije. Najveće smanjenje sadržaja POM u sintetičkom matriksu (za 85% DOC, 98% UV254 i 87% SUVA), u vodi iz Kikinde (za<br />23% DOC, 83% UV 254, 77% SUVA), i vodi iz Temerina (za 15% DOC, 80% UV<br />254 i 75% SUVA), u odnosu na vrednosti u netretiranoj vodi postignuto je pri najvećoj primenjenoj dozi od 3,0 mg O<sub> 3</sub> /mg DOC i 6000 mJ/cm 2 . Efikasnost procesa raste u vodama u kojima preovladavaju POM veće hidrofobnosti. MeĎutim, iako se O<sub> 3</sub> /UV procesom postiže visok stepen smanjenja PFTHM u sintetičkom matriksu se najbolje pokazao tretman ozonom (1,0 mg O3/mg DOC), dok se najveće smanjenje PFHAA (82%) postiže pri dozi ozona od 1,0 mg O<sub>3/</sub>mg DOC i UV zračenja od 6000 mJ/cm <sup>2 .</sup> U vodi iz Kikinde se PFTHM smanjuje za 50% pri dozi od 3,0 mg O <sub>3</sub>/mg DOC i 6000 mJ/cm 2 , dok se u slučaju uklanjanja prekursora<br />HAA ozonizacija pokazala kao superiorniji proces. U vodi iz Temerina se u pogledu uklanjanja prekursora THM i HAA ozonizacija pokazala kao optimalan proces. Visok alkalitet prirodnih voda inhibira radikalski mehanizam u toku AOP i favorizuje oksidaciju POM molekulskim ozonom. Prekursori HK se formiraju u veoma niskim koncentracijama i njihov sadržaj ne varira značajno tokom tretmana. U prirodnim matriksima tokom AOP pri dozi ozona od 3,0 mg O<sub>3</sub> /mg DOC dolazi do formiranja HAN, međutim, nije uočen jasan trend sa povećanjem doze UV zračenja. Tretman doprinosi formiranju bromovanih vrsta THM, dok se tokom AOP pri najvećoj dozi ozona od 3,0 mg O<sub>3</sub> /mg DOC formiraju bromovani HAN.<br />Najveće smanjenje sadržaja POM primenom kombinacije oksidacije sa H <sub>2</sub>O<sub>2</sub><br />i UV zračenja u sintetičkom matriksu (za do 17% DOC, 70% UV 254 ), u vodi iz Kikinde (za do 22% DOC, 53% UV<sub>254</sub>), i vodi iz Temerina (za do 7% DOC, 68% UV<br /><sub>254 </sub>), u odnosu na vrednosti u sirovoj vodi, se postižu pri dozi H <sub>2</sub>O<sub>2</sub> i UV zračenja od 3,0 mg H<sub>2</sub>O<sub>2</sub>/mg DOC i 6000 mJ/cm <sup>2</sup> .<br />Najveće smanjenje PFTHM od 54% u sintetičkom matriksu se postiže pri dozi od 0 mg H<sub>2</sub>O<sub>2</sub>/mg DOC i 6000 mJ/cm <sup>2</sup> , dok se smanjenje PFHAA (za 35%) postiže primenom doze vodonik-peroksida i UV zračenja od 1,0 mg H <sub>2</sub>O<sub>2</sub> /mg DOC i 3000 mJ/cm <sup>2</sup> . U vodi izKikinde H<sub>2</sub>O<sub>2</sub> /UV proces ne utiče značajno na sadržaj prekursora THM, dok se najveće smanjenje PFHAA (za 35%) postiže pri dozi od 3,0 mg H<sub> <span id="cke_bm_235S" style="display: none;"> </span>2<span id="cke_bm_235E" style="display: none;"> </span></sub>O<sub>2</sub>/mg DOC i 600 mJ/cm <sup>2</sup> .H<span id="cke_bm_184S" style="display: none;"> </span><sub>2</sub><span id="cke_bm_184E" style="display: none;"> </span>O<sub>2</sub><span id="cke_bm_185E" style="display: none;"> </span>/UV proces dovodi do smanjenja PFTHM u Temerinskoj vodi za 74% pri dozi od 3,0 mg H<sub>2</sub>O<sub>2</sub>/mg DOC i 600 mJ/c<span id="cke_bm_236E" style="display: none;"> </span>m <sup>2</sup> , dok primenjeni tretman ne pokazuje značajan uticaj na<br />PFHAA. Prekursori HK su detektovani u sintetičkom matriksu i temerinskoj vodi u niskim koncentracijama. U temerinskoj vodi nakon AOP pri dozi vodonik-peroksida od 3,0 mg H<sub>2</sub>O<sub>2</sub> /mg DOC dolazi do formiranja HAN i hlorpikrina. Primenjeni tretman vodi ka formiranju bromovanih DBP. Svi rezultati dobijeni u toku istraživanja ukazuju na neophodnost optimizacije procesa u tretmanu ispitivanih vodenih matriksa i određivanja optimalnog procesa uzimajući u obzir<br />karakteristika sirove vode i efikasnost koja se želi postići.Kombinacijom dva i više konvencionalnih tretmana i optimizacijom reakcionih uslova može se postići visoka efikasnost uklanjanja POM, kao i ciljano uklanjanje prekursorskog materijala odabranih DBP, međutim tretman vode ozonom pri dozi od 1,0 mg O<sub>3</sub><br />/mg DOC se pokazao kao optimalan proces.</p> / <p>The aim of the research of this PhD thesis was to determine the effects of various oxidation processes based on ozone, hydrogen peroxide and UV irradiation on the content and reactivity of natural organic matter (NOM) in different water matrices. The tests were carried out on a) groundwater from the territory of Kikinda and Temerin (natural matrix) and b) synthetic aqueous matrix (solution of commercially available humic acid), which differ in the composition and structure of NOM present and the content of bromide. For the oxidation process (ozonation, UV photolysis, oxidation with H 2O2 , combined O 3 /UV process and combined H 2O2 /UV process), the influence of different doses of oxidants and reaction conditions was examined individually. Particular attention was paid to the influence of the above treatment on the formation of inorganic bromate, as well as the effect on the content of precursors of disinfectant by-products after chlorination (THM, HAA, HAN, HK and CP).Analysis of the chemical parameters of the synthetic matrix (5.44±0.30 mg C/L; 0.255±0.015 cm -1 ; 4.68±0.41 lm -1 mg -1 ) shows that the high-hydrophobic humic compounds predominate in this water. Also, high NOM content of predominantly hydrophobic character was recorded in Kikinda water (5.170.72 mg C/L; 0.2010.001 cm -1 ; 3.88±0.70 lm -1 mg -1 ), while NOM content in raw water from Temerin (2.060.38 mg C/L; 0.0500.001 cm -1 ; 2.43±0.21 lm -1 mg -1 ) significantly lower and predominate NOM of hydrophilic character. A higher degree of hydrophobicity of the synthetic matrix in comparison with natural matrices, resulted in higher reactivity of organic matter with chlorine, which can be concluded on the basis of high PFDBP values after chlorination. The PFTHM value in the synthetic matrix was 544±85.9 µg/L, while the PFTHM in the raw waters from Kikinda and Temerin was significantly lower (279±32.3 and 180±44.0 µg/L, respectively). The PFHAA value in the synthetic matrix was 484±77.5 µg/L, while PFHAA in the Kikinda water was 223 244±11.1 µg/L and in the Temerin water was 165±32.5 µg/L. The content of precursors of HK (8.05±3.63 µg/L synthetic matrix; 14.91.38 µg/L Kikinda; 7.400.25 µg/L Temerin) was significantly lower compared to precursors of THMs and HAAs, while precursors of HANs and chloropicrin were not detected in raw water. The by- products that were predominantly formed in all the tested water matrices were chlorinated THMs and HAAs, while the brominated DBPs were formed at substantially lower concentrations. The presence of brominated DBPs in Temerine water were significantly higher compared to Kikinda water as a result of the presence of higher bromide content in raw water (0.05±0.01 mg Br -/L Temerin; 0.03±0.01 mg Br -/L Kikinda). By examining the influence of oxidation processes (UV photolysis, ozonation,hydrogen peroxide oxidation) on the content and reactivity of NOM in the tested water matrix, it was found that the UV irradiation and treatment by hydrogen peroxide, when used as an independent treatment, did not show significant efficacy in reducing the NOM content. Water treatment by ozone proved to be very effective in eliminating NOM and reducing the content of DBP precursors in all tested water matrices, as a result of the reduction of NOM reactivity to the formation of these DBPs. Reduction of NOM content in water during treatment increased with increasing the applied dose of ozone, with the best results achieved at the highest dosage of 3.0 mg O 3/mg DOC (up to 32% DOC, 92% UV 254 synthetic matrix, up to 17% DOC, 76% UV 254 Kikinda, up to 15% DOC and 66% UV254 Temerin). In the synthetic matrix the highest reduction in PFTHM (76%) and PFHAA (by 80%) compared to raw water content was achieved at a dosage of 1.0 mg O 3/mg DOC. The highest reduction in PFTHM (38%) and PFHAA (42%) in Kikinda water was achieved at a dose of 3.0 mg O3 /mg DOC. In Temerin water, the highest reduction in PFTHM (27%) was at a dose of 3.0 mg O 3/mg DOC, while the dose of 1.0 mg O3 /mg DOC was best shown for removing PFHAA (by 54%). The content of the precursors of HKs and HANs (Temerin water) was very low after treatment. Water treatment by ozone led to the formation of DBPs with more substituted bromine atoms, while in waters with a mean bromide content (50 μg Br -/L) led to bromate formation.Combination of ozonation with UV irradiation can greatly accelerate the effectiveness of NOM removal achieved by the use of ozonation alone. The highest reduction in NOM content in the synthetic matrix (by 85% DOC, 98% UV 254 and 87% SUVA), in Kikinda water (by 23% DOC, 83% UV 254 , 77% SUVA) and water from Temerin (by 15% DOC, 80% UV 254 and 75% SUVA), compared to the values in raw water, was achieved at the highest dose of 3.0 mg O 3 /mg DOC and 6000 mJ/cm 2 . The efficiency of the process was growing in the waters where NOM predominates of hydrophobicity. Although the O 3 /UV process achieved a high degree of reduction in PFTHM in the synthetic matrix the ozonation (1.0 mg O3 /mg DOC) was proved as more efficient, while the highest reduction in PFHAA (82%) was achieved at a ozone dose of 1.0 mg O 3/mg DOC and UV irradiation of 6000 mJ/cm 2 . In the water from Temerin, in case to removal of precursors of THM and HAA, ozonation was proved to be an optimal process. High alkalinity of natural waters inhibits the radical mechanism during AOP and favors NOM oxidation with molecular ozone. HKs precursors were formed at very low concentrations and their content did not vary significantly during the treatment. In natural matrices during the AOP at a ozone dose of 3.0 mg O3 /mgDOC, HANs were formed, however, there was no clear trend with increasing UV irradiation. The treatment contributed to the formation of brominated THM species, while during the AOPs, brominated HANs were formed at the maximum dose of ozone of 3.0 mg O3/mg DOC. 224 The largest decrease in NOM content by the combination of oxidation with H2O2 and UV irradiation in the synthetic matrix (for up to 17% DOC, 70% UV 254 ), in Kikinda water (up to 22% DOC, 53% UV 254), and water from Temerin (7% DOC, 68% UV 254 ), compared to the values in raw water, were obtained at a dose of H 2O2 and UV irradiation of 3.0 mg O3 /mg DOC and 6000 mJ/cm 2 . The highest PFTHM reduction of 54% in the synthetic matrix was achieved at a dosage of 1.0 mg H2O2/mg DOC and 6000 mJ/cm 2 , while a decrease in PFHAA (35%) was achieved using a dose of hydrogen peroxide and UV irradiation of 1.0 mg H2O2/mg DOC and 3000 mJ/cm 2 . In the water from Kikinda, the H2O2 /UV process did not significantly affect on the THM precursors content, while the highest reduction in PFHAA (35%) was achieved at a dose of 3.0 mg H2O2/mg DOC and 600 mJ/cm 2 . The H 2O2 /UV process led to a decrease in PFTHM in the Temerin water by 74% at a dose of 3.0 mg 2O2 /mg DOC and 600 mJ/cm 2 , whereas the treatment applied had no significant effect on PFHAA. HKs precursors were detected in synthetic matrix and the Temerin water at low concentrations. In the water after the AOP at a dose of 3.0 mg H 2O2 /mg DOC of hydrogen peroxide, HANs and chloropicrin were formed. The applied treatment led to the formation of brominated DBPs.<br />All the results obtained during the research indicate the necessity of optimization the process in the treatment of the examined water matrices and determination of the optimal process taking into account the characteristics of raw water and the efficiency to be achieved. By combining two or more conventional treatments and optimizing the reaction conditions, high NOM removal efficiency can be achieved, as well as removal of the targeted precursor material of the selected DBPs, but the treatment of ozone water at a dose of 1.0 mg O3 /mg DOC was proved to be an optimal process.</p>
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