Alternativni nosilci za TiO[sub]2 v procesih fotokatalize

magistrsko delo

Rok Oblak (Author), Urška Lavrenčič Štangar (Mentor)

Abstract

Z naraščanjem populacije na Zemlji se povečuje potreba po čisti pitni vodi, hkrati pa, zaradi dvigovanja standarda življenja, močno narašča tudi količina odpadnih vod. Za čiščenje odpadnih vod se uporabljajo številni fizikalni, biološki in kemijski procesi, katerih učinkovitost je odvisna od prisotnih onesnaževal. Napredne oksidacijske metode (NOM) se uporabljajo za razgradnjo težje razgradljivih organskih onesnaževal. Pri tem gre za kemično obdelavo odpadnih vod z namenom razgradnje organskih snovi z oksidacijo preko hidroksilnih radikalov. Dve izmed naprednih oksidacijskih metod sta tudi fotokatalitska oksidacija in fotokatalitska ozonacija. Fotokataliza običajno poteka pod UV svetlobo v prisotnosti fotokatalizatorja (npr. TiO2). Fotokatalizator je lahko suspendiran v raztopini ali pa pritrjen na različne nosilce/substrate. Drug način uporabe je sicer manj učinkovit, vendar enostavnejši in zato bolj primeren za prenos tehnologije v prakso. V svoji magistrski nalogi sem se ukvarjal z iskanjem novih nosilcev za fotokatalizator in razvojem metod za nanos TiO2 na izbrane nosilce. Kot fotokatalizator sem po opravljenih poskusih z več katalizatorji uporabil Aeroxide® TiO2 P-90, proizvajalca Evonik. Preizkusil sem dva nosilca, in sicer pletena steklena vlakna in pa mrežico iz nerjavečega jekla. Izbrana sta bila, ker sta kemijsko inertna, poleg tega pa ju je enostavno prilagajati obliki reaktorske celice. Učinkovitost nosilcev sem preverjal z razgradnjo vodnih raztopin fenola in komercialnega tekstilnega barvila, Reactive Blue 19. Razgradnjo sem izvajal v pretočnem fotoreaktorju. Za analizo vzorcev sem uporabil visokotlačno tekočinsko kromatografijo (HPLC), analizo celokupnega ogljika (TOC) in pa UV-VIS spektrofotometer. Oba nosilca sta se izkazala za učinkovita, vendar pri različnih metodah. Steklena vlakna so bila najučinkovitejša pri fotokatalitski oksidaciji, mrežica iz nerjavečega jekla pa pri fotokatalitski ozonaciji. Za oba nosilca sta bili razviti tudi metodi nanašanja TiO2.

Keywords

fotokataliza;fenoli;pretočni reaktorji;steklena vlakna;mrežice iz nerjavečega jekla;magistrske naloge;

Data

Language:	Slovenian
Year of publishing:	2015
Typology:	2.09 - Master's Thesis
Organization:	UNG FZO - Faculty of Environmental Sciences
Publisher:	[R. Oblak]
UDC:	544.3/.4
COBISS:	4036091
Views:	7448
Downloads:	310
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Alternative TiO2 supports in photocatalytic processes
Secondary abstract:	The need for fresh drinking water is rising because of Earth’s population growth. At the same time the amount of wastewaters produced is higher than ever, due to higher standard of living. Different physical, biological and chemical processes are used for wastewater treatment. Efficiency of these processes is dependent on the type of pollutants found in wastewaters. Advanced oxidation processes (AOPs) are used in degradation of extra-stable organic pollutants. AOPs are chemical processes where organic pollutants are degraded by oxidation through hydroxyl radicals. Two AOPs, commonly used are photocatalytic oxidation and photocatalytic ozonation. Photocatalysis usually occurs under UV light in presence of photocatalyst (such as TiO2). Photocatalyst can be suspended in solution or attached to different supports/substrates. Second method is less efficient, but more economically acceptable. In my master thesis I was searching for new types of support for photocatalyst and methods of applying the catalyst to chosen support. Based on experiments with different catalysts, the chosen catalyst for the experiments was Aeroxide® TiO2 P-90, by Evonik. Two different supports were used; hemmed knitted glass fiber stripes and stainless steel mesh. These two supports were used due to inertness and easy handling. Efficiency of supports was tested with degrading aqueous solutions of phenol and commercial textile dye, Reactive Blue 19. Degradation was made in flow-through reactor. Sample analyses were made by high-pressure liquid chromatography (HPLC), total organic carbon analysis (TOC) and UV-VIS spectroscopy. Both supports turned out to be efficient, but in different processes. Hemmed knitted glass fiber stripes were most efficient in photocatalytic oxidation, while stainless steel mesh was most efficient in photocatalytic ozonation. Methods for TiO2 deposition were also developed for both supports.
Secondary keywords:	TiO2 photocatalysis;P90;phenol;reactive blue 19;flow-through reactor;glass fiber;stainless steel mesh;
URN:	URN:SI:UNG
Type (COBISS):	Master's thesis/paper
Thesis comment:	Univ. v Novi Gorici, Fak. za znanosti o okolju
Pages:	VIII, 41 str.
ID:	9063296