Fotokatalitsko odstranjevanje farmacevtikov iz vode z uporabo TiO$_2$ katalizatorjev

Turk, Maruša (author), Matoh, Lev (mentor)

Farmacevtiki v odpadnih vodah so trdovratna mikroonesnaževala. V čistilnih napravah se pogosto ne odstranijo popolnoma, zato lahko vztrajajo v površinskih in podzemnih vodah, vplivajo na vodne ekosisteme in dolgoročno povečujejo tveganja za človeka in živali. Ker poraba zdravil narašča, narašča tudi obremenitev okolja z ostanki učinkovin in njihovimi metaboliti. Za obvladovanje takih onesnaževal so potrebni postopki, ki so sposobni razgraditi molekule do manj škodljivih produktov ali jih mineralizirati. Heterogena fotokataliza na osnovi TiO₂ je med obetavnejšimi pristopi, ker omogoča tvorbo močnih oksidativnih vrst (npr. •OH), ki napadajo širok nabor organskih spojin. TiO₂ je pri tem privlačen zaradi kemijske stabilnosti, netoksičnosti, dostopnosti in možnosti uporabe pod UV-osvetlitvijo. Namen raziskave je bil ugotoviti, kako učinkovito se lahko izbrana farmacevtska onesnaževala razgradijo s fotokatalizo pod UV svetlobo, hkrati pa preveriti vpliv dodane platine na učinkovitost TiO₂ kot katalizatorja. V ta namen sem najprej sintetizirala TiO₂. Del tako sintetiziranega TiO₂ sem prevlekla z nanosi platine, da sem pridobila platiniziran katalizator, nato pa izvedla serijo fotokatalitskih testov v vodnih raztopinah izbranih farmacevtikov pod UV osvetljevanjem. Koncentracije farmacevtskih spojin pred in po obsevanju sem določila s tekočinsko kromatografijo visoke ločljivosti (HPLC), stopnjo mineralizacije pa sem določevala z analizo celokupnega organskega ogljika (TOC). Rezultati so pokazali, da so nekatere testirane farmacevtske spojine manj obstojne od drugih. Določene učinkovine so se pod navedenimi pogoji popolnoma razgradile, medtem ko drugih ni bilo mogoče povsem odstraniti. Fotokatalitske poskuse sem izvedla tudi z mešanico štirih različnih farmacevtikov, pri čemer so bili dobljeni rezultati malo drugačni kot pri posameznih spojinah. Ta razlika ponazarja kompleksnost procesov, kadar je v vodi hkrati prisotnih več različnih onesnaževal farmacevtskega izvora. Cilj je prispevati k boljšemu razumevanju, kako takšne tehnologije lahko dopolnijo klasično čiščenje odpadnih vod.

• Language: Slovenian
• Keywords: fotokataliza, titanov dioksid, farmacevtiki
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2025
• PID: 20.500.12556/RUL-173349
• COBISS.SI-ID: 257942019
• Publication date in RUL: 16.09.2025

Secondary language

• Language: English
• Title: Photocatalytic removal of pharmaceuticals from water using TiO$_2$ catalysts

Abstract

Pharmaceuticals in wastewater are persistent micro-pollutants. They are often not completely removed in wastewater treatment plants, so they can persist in surface and groundwater, affect aquatic ecosystems, and, in the long term, increase risks to humans and animals. As drug consumption grows, environmental burdens from residual active ingredients and their metabolites also rise. To address such pollutants, methods are needed that can degrade molecules into less harmful products or mineralize them. Heterogeneous photocatalysis based on TiO₂ is among the most promising approaches, as it enables the formation of strong oxidative species (e.g., •OH) that attack a wide range of organic compounds. TiO₂ is attractive due to its chemical stability, non-toxicity, availability, and the possibility of operation under UV irradiation. The aim of the study was to determine how effectively selected pharmaceutical pollutants can be degraded by photocatalysis under UV light and to assess the effect of platinum addition on the efficiency of TiO₂ as a catalyst. To this end, I first synthesized TiO₂. Part of the synthesized TiO₂ was coated with platinum to obtain a platinized catalyst, followed by a series of photocatalytic tests in aqueous solutions of selected pharmaceuticals under UV irradiation. Concentrations of the pharmaceutical compounds before and after irradiation were determined by high-performance liquid chromatography (HPLC), while the degree of mineralization was evaluated by total organic carbon (TOC) analysis. The results showed that some of the tested pharmaceuticals are less persistent than others: certain compounds were completely degraded under the given conditions, whereas others could not be fully removed. Photocatalytic experiments were also performed with a mixture of four different pharmaceuticals, yielding results that differed somewhat from those obtained for the individual compounds. This difference illustrates the complexity of processes when multiple pharmaceutical pollutants are present simultaneously in water. The goal is to contribute to a better understanding of how such technologies can complement conventional wastewater treatment.

• Keywords: photocatalysis, titanium dioxide (TiO₂), pharmaceutical