Title Uklanjanje farmaceutika iz voda naprednim oksidacijskim procesom uz Sunčevo zračenje Title (english) Removal of pharmaceuticals from water by solar assisted advanced oxidation processes Author Daria Juretić Perišić Mentor Ana Lončarić Božić (mentor)Committee member Hrvoje Kušić (predsjednik povjerenstva)Committee member Marin Kovačić (član povjerenstva)Committee member Urška Lavrenčič Štangar Granter University of Zagreb Defense date and country 2019-10-04, Croatia Scientific / art field, TECHNICAL SCIENCES Universal decimal classificationUDC ) 66 - Chemical technology. Chemical and related industries Abstract Prisutnost farmaceutika u vodenom okolišu u najvećoj je mjeri posljedica njihovog neučinkovitog uklanjanja na konvencionalnim uređajima za obradu komunalnih otpadnih voda. Razvojem i primjenom naprednih procesa dodatne obrade otpadnih voda mogu se ukloniti mikroonečišćivala poput farmaceutika. Jedan od najčešće detektiranih farmaceutika u okolišu, diklofenak (DCF), karakteriziraju toksičnost prema V. fischeri, mala biorazgradivosti te nije podložan fotolizi ni hidrolizi u okolišnim uvjetima. Napredni oksidacijski procesi, uz Sunčevo zračenje, pokazuju veliki potencijal kao tehnologija uklanjanja zaostalih organskih mikroonečišćivala. U ovom radu istraživana je mogućnost uklanjanja DCF-a iz vode pomoću novog kompozitnog fotokatalizatora baziranog na titanijevom dioksidu i željezom modificiranom ZSM5 sintetskom zeolitu uz Sunčevo zračenje. TiO2 karakterizira velika fotokatalitička aktivnost pod UV-A zračenjem te se učinkovitost procesa obrade dodatno povećava uvođenjem vodikova peroksida. Željezom modificirani zeolit (FeZ) pokazao je veliki adsorpcijski afinitet prema DCF-u u kiselom pH području kompleksiranjem površinski dostupnog Fe s deprotoniranom karboksilnom skupinom DCF-a, dok je pod UV-A zračenjem, uz prisutnost vodikova peroksida, fotokatalitički aktivan. Novi kompozitni fotokatalizator (TiO2-FeZ) objedinjuje fotoaktivnost TiO2 te djelovanje FeZ-a kao heterogenog katalizatora Fentonova tipa uz izvrsna adsorpcijska svojstva. DRS analizom utvrđen je linearan odnos između smanjenja širine zabranjene zone TiO2-FeZ i masenog udjela Fe, što ukazuje na prisutnost Ti-O-Fe veze koja utječe na smanjenje širine zabranjene zone uz pomicanje fotoaktivnosti prema vidljivom spektru. Učinkovitost istraživanih fotokatalitičkih procesa obrade voda vrednovana je putem uklanjanja i mineralizacije DCF-a HPLC i TOC analizom te praćenjem promjene ekoloških pokazatelja kvalitete vode (biorazgradivost BPK5/KPK, toksičnost na V. fischeri). Imobilizirani kompozitni TiO2-FeZ fotokatalizator na staklenim nosačima u kiselom području pokazuje bolju fotokatalitičku aktivnost pod simuliranim Sunčevim zračenjem u odnosu na TiO2. Povećanjem masene koncentracije TiO2-FeZ postiže se pozitivan utjecaj na učinkovitost uklanjanja i konverzije DCF-a do 4 imobilizirana sloja fotokatalizatora, nakon čega se gubi mehanička stabilnost te dolazi do erozije imobiliziranog filma. Razgradnja DCF-a inicirana je adsorpcijom na površinu TiO2-FeZ nakon čega slijedi hidroksilacija i/ili cijepanje C-N veze što je utvrđeno identifikacijom i praćenjem razgradnih međuprodukata MS/MS-om. Prisutnost anorganskih aniona Cl- i SO4 2- negativno utječe na adsorpciju DCF-a zbog kompetitivne kinetike posljedično i na razgradni put. U prisutnosti Cl- postiže se visoki stupanj mineralizacije, biorazgradivost te niska toksičnost. Mogućnost ponovnog korištenja TiO2-FeZ fotokatalizatora ispitana je provođenjem uzastopnih ciklusa obrade te su testirane toplinska i kemijska reaktivacija ozonacijom. Pokazano je da se uz kemijsku reaktivaciju ozonacijom u pet uzastopnih ciklusa obrade očuvala visoka aktivnost fotokatalizatora. TiO2-FeZ karakteriziraju superiorna fotokatalitička svojstva u odnosu TiO2 i željezom modificirani zeolit pod simuliranim Sunčevim zračenjem što ukazuje na potencijal uporabe novog kompozitnog fotokatalizatora u okolišno prihvatljivim tehnologijama uklanjanja mikroonečišćivala iz voda.
Abstract (english) Pharmaceuticals are mainly introduced into aquatic environment through wastewater treatment plant effluents due to ineffective removal. Diclofenac (DCF) is one of the most commonly detected pharmaceuticals in the environment. DCF is characterized by low biodegradability and toxicity to V. fischeri. DCF isn’t susceptible to direct photolysis or hydrolysis in the environment. Development and implementation of advanced oxidation processes activated by Solar irradiation may represent a potentially attractive technology for the removal of residual organic pollutants like pharmaceuticals. In this thesis DCF removal from water was investigated employing novel composite photocatalyst based on titanium dioxide and synthetic ZSM5 zeolite with cation-exchanged iron (FeZ) under Solar irradiation. TiO2 is characterized by excellent photocatalytic activity under UV-A irradiation, which is further augmented by introducing hydrogen peroxide as an oxidant and electron scavenger. FeZ showed significant adsorption capacity towards DCF at acidic pH via complexation of DCF deprotonated ethanoic functional group with surface Fe(III). Furthermore, surface Fe(III) ions under UV-A irradiation in presence of H2O2 act as heterogeneous photo-Fenton like catalyst. The novel composite (TiO2-FeZ) photocatalyst combines the photoactivities of TiO2 and FeZ, together with heterogeneous Fenton like catalyst activity and superb adsorption capacity of FeZ. DRS analysis showed a linear correlation of band gap decrease with an increase of FeZ wt%, indicating the formation of Ti-O-Fe bond that affects band gap with alteration of composite photoactivity toward visible spectrum. Efficiency of the investigated water treatment processes was evaluated through DCF removal by HPLC analysis and mineralization by TOC and the change of sum water parameters (biodegradability (BOD5/COD) and toxicity to V. fischeri). The TiO2-FeZ composite photocatalyst immobilized on glass support showed superior photocatalytic activity under simulated Solar irradiation in comparison TiO2 in acidic pH. Increasing the TiO2-FeZ photocatalyst loading showed a positive influence on process efficiency, i.e. removal and conversion of DCF, up to 4 layers of immobilized photocatalyst. Above 4 layers the loss of mechanical stability followed by photocatalyst thin film erosion was determined. DCF conversion is initiated by adsorption on the TiO2-FeZ surface, followed by hydroxylation and CN bond cleavage under illumination which was determined by MS/MS analysis for the identification and quantitation of DCF degradation by-products. Inorganic anions (Cl- and SO4 2-) negatively affect DCF adsorption due to competitive kinetics, which affects degradation pathway and efficiency. In the presence of Cl- high rate of mineralization, biodegradability and low toxicity were achieved. Potential reuse of the immobilized TiO2-FeZ photocatalyst was tested performing consecutive runs with testing efficiency of thermal and chemical reactivation of the photocatalyst. Chemical reactivation with ozonation yielded high photocatalyst activity in five consecutive runs. TiO2-FeZ photocatalyst retained superior photocatalytic activity in comparison to TiO2 or FeZ alone under simulated Solar irradiation, which implies the potential of the novel TiO2-FeZ composite photocatalyst in environmentally friendly water treatment technologies for micropollutant removal.
Keywords
diklofenak
modificirani zeolit
TiO2
fotokataliza
TiO2-FeZ
simulirano Sunčevo zračenje
ekološki pokazatelji kvalitete vode
reaktivacija fotokatalizatora
Keywords (english)
diclofenac
modified zeolite
TiO2
photocatalysis
TiO2-FeZ
simulated Solar irradiation
sum water parameters
catalyst reactivation
Language croatian URN:NBN urn:nbn:hr:149:159982 Promotion 2019 Project Number: UIP-2013-11-7900 Study programme Title: Chemical Engineering - Doctoral Course Type of resource Text Extent 187, XXI str ; 30 cm File origin Born digital Access conditions Closed access Terms of use Created on 2023-08-28 12:19:10
