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Porast ljudske populacije i globalni razvoj rezultiraju rastućom potrošnjom vode, a time i povećanjem količine otpadnih voda. Neadekvatno obrađene otpadne vode, dospijećem u prirodne prijamnike, pridonose onečišćenju vode. Posebno su zabrinjavajuća farmaceutska mikroonečišćivala detektirana u vodama diljem svijeta, za čije uklanjanje nisu dostatni konvencionalni postupci obrade voda. Nesteroidni protupalni lijek diklofenak ubraja se u farmaceutska onečišćivala. Diklofenak iz ljudskog organizma izlazi dijelom nepromijenjem i dijelom u obliku raznih metabolita te dospijeva u otpadne vode. Konvencionalnim metodama obrade vode moguće je ukloniti samo dio prisutnog diklofenaka, stoga se okreće novim tehnologijama poput naprednih oksidacijskih procesa. U ovom radu ispitana je učinkovitost fotokataltičke razgradnje diklofenaka pod simuliranim Sunčevim zračenjem uz BiVO4 fotokatalizator. Ispitani su utjecaji metode sinteze fotokatalizatora, pH i dodatka modifikatora na fotokatalitičku razgradnju diklofenaka. Fotokatalizator sintetiziran metodom precipitacije pokazuje bolju fotokatalitičku aktivnost u odnosu na fotokatalizator sintetiziran hidrotermalnom metodom. Nadalje, dodatak modifikatora EDTA i povišenje pH pogoduju fotokatalitičkom uklanjanju diklofenaka. Najveća fotokatalitička aktivnost ostvarena je pri pH= 7,5 uz BiVO4 fotokatalizator sintetiziran precipitacijom s dodatkom EDTA. Ostvareno uklanjanje nakon 180 min provedbe procesa pod simuliranim Sunčevim zračenjem iznosi 34,5%, dok pod vidljivim zračenjem iznosi 56,1%. The population growth and global development are resulting in an increase in water consumption, leading to an increase in amount of waste water. Inadequately treated waste water enters water sources and contributes to pollution of the water environment. Pharmaceutical micropollutants which are detected in water around the world present a great jeopardy, due to the insufficient removal by conventional water treatment. Among them is diclofenac, non-steroidal anti-inflammatory drug. Diclofenac is being released into the environment partially unchanged and as its metabolites. Since diclofenac can only be partially removed by conventional water treatments it is necessary to develop new methods such as advanced oxidation processes. This study questions the efficiency of photocatalytical processes in diclofenac removal under simulated solar irradiation using BiVO4 photocatalyst. The study investigated influences of BiVO4 preparation method, pH and different additives on photocatalytic removal of diclofenac. Photocatalysts synthesized by precipitation method shows higher photocatalytic activity than photocatalysts synthesized by hidrothermal method. Furthermore, addition of EDTA and increase in pH result in higher photocatalytical activity. The highest photocatalytical activity has been achieved with pH= 7,5 and BiVO4 photocatalyst synthesized by precipitation method with addition of EDTA. Achieved diclofenac removal after 180 min is 34,5 % under simulated solar irradiation and 56,1 under visible light irradiation.

Uslijed sve veće proizvodnje i terapeutske primjene farmaceutika, otpadne vode onečišćene su farmaceuticima poput diklofenaka (DCF) te predstavljaju značajan ekološki problem. Farmaceutici spadaju u grupu mikroonečišćivala, čija se sve veća prisutnost primjećuje u površinskim i podzemnim vodama. Glavni izvor krije se u nedovoljnoj učinkovitost konvencionalnih metoda obrade, zbog čega se u posljednje vrijeme sve veća pažnja pridaje naprednim oksidacijskim procesima kao obećavajućim metodama uklanjanja mikroonečišćivala. Jedan od takvih procesa je i fotokataliza, proces razgradnje onečišćujućih tvari pod utjecajem UV/VIS zračenja uz prisutnost fotokatalizatora na kojem dolazi do efekta adsorpcije tih tvari i njihove razgradnje uslijed djelovanja radikalskih vrsta. U ovom radu prikazan je postupak sinteze BiVO4 fotokatalizatora, jednog od novijih i sve više istraživanih fotokatalizatora. Zanimljiv je upravo zbog fotokatalitičke aktivnosti pod utjecajem vidljive svjetlosti. Fotokatalizator je sintetiziran hidrotermalnom i sol-gel metodom, pri čemu se sol-gel metoda pokazala neuspješnom. Termogravimetrijskom analizom hidrotermalnog BiVO4 ustanovljena je velika količina etilen glikola preostalog iz sinteze u uzorku. Učinkovitost uklanjanja diklofenaka DCF-a hidrotermalnim BiVO4 ispitana je u suspenziji pri pH 4, 6 i 8, pod simuliranim Sunčevim zračenjem, pri čemu je uklanjanje DCF-a praćeno tekućinskom kromatografijom visoke djelotvornosti. Nakon 60 min fotokatalitičke obrade pri pH 4 uklonjeno je 31,67 % DCF-a, dok pri pH 4 i pH 8 tek 12,32 %, odnosno 3,12 % DCF-a. Uklanjanje DCF-a moglo se opisati gotovo podjednako dobro kinetičkim modelom 1. i 2. reda na temelju ocjenjivanja koeficijenta regresije. U daljnjim istraživanjima potrebno je poboljšati čistoću dobivenog BiVO4. Due to the increasing production and therapeutic use of pharmaceuticals, wastewater is contaminated by pharmaceuticals, such as diclofenac (DCF), and represents a significant environmental problem. Pharmaceuticals belong to the group of micropollutants, whose increasing presence is observed in surface and groundwater. The main source lies in the lack of efficiency of conventional treatment methods, which is why more and more attention has been recently given to advanced oxidation processes as promising methods for the removal of micropollutants. Amongst them is photocatalysis, a process for the degradation of pollutants under the influence of UV/VIS irradiation in the presence of a photocatalyst on which adsorption of these substances occurs and subsequent degradation by radical species. This work describes the synthesis process of BiVO4 photocatalysts, one of the more recent and increasingly studied photocatalysts. It is interesting because of photocatalytic activity under the influence of visible light. The photocatalyst was synthesized by hydrothermal and sol-gel methods. The sol-gel method was unsuccessful. Hydrothermal BiVO4 was analysed by thermogravimetric analysis, which revealed a large quantity of residual ethylene glycol within the sample. The efficiency (DCF) in water under simulated solar irradiation, samples were analyzed by high performance chromatograph. Removal efficiency was tested in suspension at pH values of 4, 6 and 8. At pH 4 the removal of DCF equaled 31.67%, whereas at pH 6 and 8 the removal was 12.32 % and 3.12 % respectively. The removal of DCF could be almost equally well fitted to 1st and 2nd order kinetic models, on the basis of regression coefficients. In further research, it is necessary to improve the purity of the obtained BiVO4.