| Sažetak | Farmaceutici su sveprisutni u našem svakodnevnom životu i time vrlo lako dospijevaju u okoliš. Primarni put njihovog ulaska u okoliš je kroz izvore otpadnih voda. Farmaceutici i njihovi metaboliti koji se prenose otpadnom vodom u rijeke i potoke uzrokuju velike probleme u cijelom ekosustavu i vrlo ju je važno prije ispuštanja u vodotokove adekvatno obraditi. Konvencionalni biološki i kemijski postupci obrade otpadnih voda su neučinkoviti zbog bio-nerazgradive prirode mnogih farmaceutika pa se stoga istražuju napredni oksidacijski procesi. Kao jedan od naprednih oksidacijskih procesa u ovom se radu provodi fotokataliza uz katalizator koji je napravljen nanošenjem TiO2 filma na Al2O3 keramičku, pjenastu podlogu pri čemu je kao izvor zračenja korištena UV lampa. U ovom radu ispitan je utjecaj različitih parametara na fotokatalitičku razgradnju prokaina. Prvo je provedena validacija metode za praćenje prokaina u vodi. Nakon toga proveli su se preliminarni eksperimenti kojima se potvrdilo da smanjenje koncentracije prokaina u otopini nije povezano s njegovom hidrolitičkom razgradnjom niti njegovom adsorpcijom na fotokatalizator. Također, određena je i kinetika fotokatalitičke razgradnje prokaina koja se može opisati reakcijom razgradnje prvog reda. Nadalje, provođenjem eksperimenata kojima se ispitao utjecaj pH vrijednosti otopine i koncentracije prokaina određeni su optimalni uvjeti za provođenje fotokatalitičke razgradnje pri čemu koncentracija prokaina iznosi 10 mg/L, a pH vrijednost otopine 10. Ispitivanjem utjecaja slobodnih radikala na mehanizam razgradnje pokazalo se da šupljine imaju značajnu ulogu. Prilikom ispitivanja utjecaja matice vode utvrđeno je da nitrati i kloridi blago usporavaju fotokatalitičku reakciju razgradnje prokaina, a hidrogenkarbonati povećavaju brzinu razgradnje, ali sama promjena koncentracije navedenih tvari u otopini ne utječe na brzinu razgradnje. S druge strane, povećanjem koncentracije huminske kiseline smanjuje se brzina fotokatalitičke razgradnje. Razgradni produkti određeni nakon provođenja eksperimenta pri optimalnih uvjetima su RP-1 s m/z 120 i RP-2 s m/z 138. Na kraju se provela i procjena razvojne toksičnosti, mutagenosti i bioakumulacijskog faktora prokaina i nastalih razgradnih produkata računalnim programom TEST. |
| Sažetak (engleski) | Pharmaceuticals are ubiquitois in our daily lives and therefore easily enter the environment. They enter the environment primarly through wastewater. Pharmaceuticals and their metabolites that enter rivers and streams with wastewater are a major problem for the entire ecosystem, and it is very important to treat them properly before they enter waterways. Conventional biological and chemical wastewater treatment methods are ineffective due to the biodegradability of many pharmaceuticals, so advanced oxidation methods are being researched. As one of the advanced oxidation methods, photocatalysis is carried out in this work with a catalyst prepared by depositing a TiO2 film on an Al2O3 ceramic foam substrate, using a UV lamp as a radiation source. In this work, the influence of various parameters on the photocatalytic degradation of procaine was investigated. First, the validation of the method for monitoring procaine in water was carried out. Then, preliminary experiments were performed, which confirmed that the decrease of procaine concentration in solution was not related to its hydrolytic degradation or adsorption to the photocatalyst. Moreover, the kinetics of the photocatalytic decomposition of procaine was determined, which can be described by a first-order decomposition reaction. In addition, experiments that investigated the influence of solution pH value and the procaine concentration, the optimal conditions for carrying out photocatalytic decomposition, where the procaine concentration is 10 mg/L and the solution pH is 10. When studying the influence of free radicals on the decomposition mechanism, it was found that the holes played an important role. When the influence of water matrix was studied, it was found that nitrates and chlorides slightly slow down the photocatalytic reaction of procaine decomposition and hydrogen carbonates increase the rate of decomposition, but the mere change of the concentration of the mentioned substances in the solution does not affect the rate of decomposition. Increasing the concentration of humic acid, on the other hand, decreases the photocatalytic degradation rate. The degradation products determined after performing the experiment under optimal conditions are RP-1 with m/z 120 and RP-2 with m/z 138. Finally, an evaluation of the developmental toxicity, mutagenicity, and bioaccumulation factor of procaine and the resulting degradation products was performed using the computer program TEST. |
