teoretično ozadje in primer laboratorijske izvedbe
Karmen Groznik (Author), Urška Lavrenčič Štangar (Mentor)

Abstract

Heterogena fotokataliza sodi med napredne oksidacijske postopke (NOP) za odstranjevanje težko razgradljivih organskih pa tudi nekaterih anorganskih snovi. Pri tej metodi se kot fotokatalizator uporablja polprevodnik, ki ga vstavimo v reaktor in izvedemo fotokatalitsko reakcijo z osvetljevanjem z UV ali vidno svetlobo. Za namene izvajanja fotokatalitskih reakcij se tako v laboratoriju kot v industriji uporabljajo različne vrste reaktorskih sistemov. Delimo jih na tri skupine glede na vrsto uporabljenega fotokatalizatorja (suspendiran/imobiliziran), vrsto sevanja (UV/VIS/sončna svetloba) in glede na lokacijo uporabljenega vira sevanja (potopljen/zunanji/razporejen). Pri eksperimentalnem delu diplomske naloge smo spremljali učinkovitost fotokatalitske razgradnje za izbrana organska onesnaževala. Uporabili smo raztopine organskega barvila plazmokorint B ter farmacevtikov ciprofloksacina in oksitetraciklina hidroklorida. Z metodami UV-VIS spektroskopije in HPLC smo spremljali, kolikšna je adsorpcija posameznega onesnaževala v temi ter določili fotokatalitsko učinkovitost TiO2. Ta je bil imobiliziran na steklene kroglice, ki so bile naložene v cev fotoreaktorske celice. Pri raztopini barvila smo z večkratno uporabo katalizatorja spremljali še stabilnost nanosa. S ponovitvami fotokatalize raztopine plazmokorinta B smo ugotovili, da se imobilizirani TiO2 tekom razkroja onesnaževala ne izpira, kar omogoča njegovo večkratno uporabo. Učinkovitost oz. uspešnost fotokatalitske razgradnje smo dokazovali z raztopino ciprofloksacina, katerega razgradnja je bila 95 %. Pri omenjenih raztopinah smo koncentracijo onesnaževal spremljali z UV-VIS spektroskopijo. V nadaljevanju smo preučevali še razgradnjo raztopine oksitetraciklin hidroklorida, pri čemer smo s HPLC meritvami zaznali nastanek intermediata, ki se je nato uspešno razgradil.

Keywords

heterogena fotokataliza;fotokatalitski reaktorji;titanov dioksid;sol-gel metoda;odpadne vode;razgradnja organskih onesnaževal;diplomske naloge;

Data

Language: Slovenian
Year of publishing:
Typology: 2.11 - Undergraduate Thesis
Organization: UL FKKT - Faculty of Chemistry and Chemical Technology
Publisher: [K. Groznik]
UDC: 544.526.5:546.82-31(043.2)
COBISS: 89722371 Link will open in a new window
Views: 209
Downloads: 25
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Other data

Secondary language: English
Secondary title: Flow photocatalytic reactors for water treatment: theoretical background and case study
Secondary abstract: Heterogeneous photocatalysis is one of the advanced oxidation processes (AOP) for the removal of poorly degradable organic as well as some inorganic substances. In the method, a semiconductor is used as a photocatalyst, which is inserted into the reactor, and the photocatalytic reaction is carried out by illumination with UV or visible light. Various types of reactor systems are used in both laboratory and industrial settings to perform photocatalytic reactions. The reactors are divided into three groups according to the type of photocatalyst used (suspended/immobilized), the type of radiation (UV/VIS/sunlight) and the location of the radiation source used (immersed/external/distributed). In the experimental part of the work, we investigated the efficiency of photocatalytic degradation for selected organic pollutants. Solutions of organic dye plasmocorinth B and pharmaceuticals ciprofloxacin and oxytetracycline hydrochloride were used. UV-VIS spectroscopy and HPLC methods were used to monitor the adsorption of each pollutant in the dark and to determine the photocatalytic efficiency of TiO2. This was immobilized on glass beads loaded into the tube of the photoreactor cell. In the case of the dye solution, the stability of the deposit was monitored by repeated use of the catalyst. In the case of repeated photocatalysis of plasmocorinth B solution, we found that the immobilized TiO2 is not washed off during the degradation of the pollutant, which allows its repeated use. The efficiency of photocatalytic degradation was demonstrated with a ciprofloxacin solution, which was 95% degraded. For these solutions, the contaminant concentration was monitored by UV-VIS spectroscopy. Then, the degradation of oxytetracycline hydrochloride solution was studied, and HPLC measurements showed the formation of an intermediate, which was then successfully degraded.
Secondary keywords: heterogeneous photocatalysis;titanium dioxide;sol-gel method;decomposition of organic pollutants;
Type (COBISS): Bachelor thesis/paper
Study programme: 1000374
Thesis comment: Univ. v Ljubljani, Fak. za kemijo in kemijsko tehnologijo, VSŠ Kemijska tehnologija
Pages: 41 str.
ID: 14075167