magistrsko delo
Jasmin Račić (Avtor), Helena Prosen (Mentor), Franc Požgan (Član komisije za zagovor), Irena Kralj Cigić (Član komisije za zagovor)

Povzetek

Emergentna onesnaževala so spojine iz naravnih ali sintetičnih virov, ki imajo znane ali domnevne škodljive učinke na okolje in zdravje človeka. Benzotriazoli (BTA) so emergentna onesnaževala, ki so akutno strupena za nekatere bakterije in vodne organizme. Alkil etoksilati (APEO) in njihovi stabilni razgradni produkti alkilfenoli (AP) so onesnaževala, ki so akutno in kronično strupena za alge, ribe in nevretenčarje. Pri vretenčarjih se vežejo za estrogenske receptorje in delujejo kod endokrini motilci. Trenutne metode za odstranjevanje emergentnih onesnaževal iz okolja, kot so biološka razgradnja in adsorbcija, se niso izkazale kot najbolj učinkovite metode in lahko tvorijo produkte, ki so še bolj strupeni od izhodnih onesnaževal. Novi pristop za odstranjevanje emergentnih onesnaževal iz vodnega okolja, zlasti odpadne vode, je uporaba t.i. naprednih oksidacijskih procesov (AOP), med katere sodijo elektrooksidacija (EO) in ozonacija, ki temeljijo na tvorbi reaktivnih kisikovih zvrsti pri sobni temperaturi, te pa potem oksidirajo onesnaževala. Za BTA smo spremljali učinkovitost EO z uporabo različnih anodnih materialov, in sicer anodo iz z borom dopiranega diamanta (BDD) ter anodo iz mešanih kovinskih oksidov (MMO) RuO2 in RuO2/IrO2. Kot najbolj učinkovita anoda se je izkazala BDD, pri kateri se je po 60 min razgradilo 81,1 % BTA. Pri uporabi vseh elektrod sem identificiral nastanek 1H-BTA-4,7-diona, BTA-OH, BTA-(OH)2 in BTA-(OH)3. BDD anodo smo potem uporabili za EO BTA v modelni odpadni vodi z dodatkom H2SO4, Na2SO4 in NaCl kot pomožnih elektrolitov. Kot najbolj učinkovit elektrolit se je izkazala H2SO4, pri kateri se je po 60 min razgradilo 97,7 % BTA. Z dodatkom H2SO4 in Na2SO4 sem med EO identificiral nastanek BTA-OH, BTA-(OH)2 in BTA-(OH)3, medtem ko slednji metaboliti niso bili opaženi pri dodatku NaCl. Z dodatkom NaCl sem identificiral nastanek BTA-Cl. Za spremljanje ozonacije AP sem razvil HPLC-DAD metodo in GC-MS/MS metodo. HPLC-DAD metoda je bila linearna v območju med 0,5 mg/L in 50 mg/L z RSD injiciranja pod 6,4 %. GC-MS/MS metoda je bila linearna v območju med 10 μg/L in 500 μg/L z RSD injiciranja med 1,2 % in 8,3 %. Optimiziral sem tudi SPE, pri čemer se je kot najbolj učinkovita kolona izkazala C18 z izkoristki ekstrakcije med 47,7 % in 86,5 %. pH ni imel bistvenega vpliva na izkoristke, medtem ko je dodatek elektrolitov nekoliko zvišal izkoristke za 4-t-oktilfenol in znižal za ostale AP. Optimalen volumen eluenta MeOH je bil 2 mL. Prebojni volumen je bil 500 mL. Pri ozonaciji smo spremljali učinkovitost ozonacije realne odpadne vode, ki je vsebovala AP, z dodatkom dveh različnih heterogenih zeolitnih katalizatorjev in sicer ZEO in ZEO(Fe). ZEO(Fe) se je iskazal kot dosti bolj učinkovit katalizator, pri katerem smo dosegli popolno mineralizacijo AP po 40 min, medtem ko smo v primeru ZEO popolno mineralizacijo AP dosegli po 110 min.

Ključne besede

emergentna onesnaževala;alkilfenoli;benzotriazoli;napredni oksidacijski procesi;masna spektrometrija;HPLC-DAD;GC-MS/MS;ekstrakcija na trdno fazo;magistrska dela;

Podatki

Jezik: Slovenski jezik
Leto izida:
Tipologija: 2.09 - Magistrsko delo
Organizacija: UL FKKT - Fakulteta za kemijo in kemijsko tehnologijo
Založnik: [J. Račić]
UDK: 543.544:543.51:504.5(043.2)
COBISS: 163991555 Povezava se bo odprla v novem oknu
Št. ogledov: 7
Št. prenosov: 0
Ocena: 0 (0 glasov)
Metapodatki: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Ostali podatki

Sekundarni jezik: Angleški jezik
Sekundarni naslov: Monitoring of transformation products formed during application of advanced oxidation processes on selected pollutants
Sekundarni povzetek: Emergent pollutants are compounds from natural or synthetic sources that have known or suspected adverse effects on the environment and human health. Benzotriazoles (BTA) are emergent pollutants that are acutely toxic to certain bacteria and aquatic organisms. Alkylphenol ethoxylates (APEO) and their stable degradation products alkylphenols (AP) are pollutants that are acutely and chronically toxic to algae, fish and invertebrates. In vertebrates, they bind to estrogen receptors and act as endocrine disruptors. Current methods for removing emerging contaminants from the environment, such as biological degradation and adsorption, have not proven to be the most effective methods and may produce products that are even more toxic than the original contaminants. A new approach for removing emergent pollutants from the aqueous environment, especially wastewater, is the use of so-called advanced oxidation processes (AOP), including electro-oxidation (EO) and ozonation, which are based on the formation of reactive oxygen species at room temperature that then oxidise the pollutants. For BTA, the performance of EO using different anode materials, namely the boron-doped diamond (BDD) anode and the RuO2 and RuO2/IrO2 mixed-metal oxide (MMO) anodes, was monitored. BDD was found to be the most efficient anode, with 81.1% BTA degradation after 60 min. The formation of 1H-BTA-4,7-dione, BTA-OH, BTA-(OH)2 and BTA-(OH)3 was identified with all electrodes. The BDD anode was then used for EO of BTA in model wastewater with the addition of H2SO4, Na2SO4 and NaCl as supporting electrolytes. H2SO4 was found to be the most effective electrolyte, with 97.7% BTA degradation after 60 min. With the addition of H2SO4 and Na2SO4, the formation of BTA-OH, BTA-(OH)2 and BTA-(OH)3 was identified among the EOs, while the latter metabolites were not observed with the addition of NaCl. With the addition of NaCl, the formation of BTA-Cl was identified during EO. To monitor the ozonation of AP, I have developed an HPLC-DAD method and a GC-MS/MS method. The HPLC-DAD method was linear in the range between 0.5 mg/L and 50 mg/L with an injection RSD below 6.4%. The GC-MS/MS method was linear in the range between 10 µg/L and 500 µg/L with an injection RSD between 1.2% and 8.3%. I also optimised the SPE, with C18 proving to be the most efficient column with extraction recoveries between 47.7% and 86.5%. pH had no significant effect on the recoveries, while the addition of electrolytes slightly increased the recoveries for 4-t-octylphenol and lowered them for the other APs. The optimum MeOH eluent volume was 2 mL. The breakthrough volume was 500 mL. The ozonation efficiency of real wastewater containing AP was monitored by adding two different heterogeneous zeolite catalysts, ZEO and ZEO(Fe). ZEO(Fe) proved to be a much more efficient catalyst, with complete AP mineralisation achieved after 40 min, while in the case of ZEO, complete AP mineralisation was achieved after 110 min.
Sekundarne ključne besede: alkylphenols;benzotriazoles;emergent pollutants;chromatography;mass spectrometry;solid-phase extraction;advanced oxidation processes;Oksidacija;Kromatografija;Univerzitetna in visokošolska dela;
Vrsta dela (COBISS): Magistrsko delo/naloga
Študijski program: 1000375
Konec prepovedi (OpenAIRE): 1970-01-01
Komentar na gradivo: Univ. v Ljubljani, Fak. za kemijo in kemijsko tehnologijo, smer Kemija
Strani: 64 str.
ID: 19908955