Title Fotorazgradnja imidakloprida na suspendiranom fotokatalizatoru u prisutnosti permanentnog magneta Title (english) Photodegradation of imidacloprid on a suspended photocatalyst in the presence of a permanent magnet Author Karlo Sklepić Mentor Vanja Kosar (mentor)Committee member Vanja Kosar (predsjednik povjerenstva)Committee member Vesna Tomašić (član povjerenstva)Committee member Lidija Furač (član povjerenstva)Granter University of Zagreb Defense date and country 2022-09-15, Croatia Scientific / art field, TECHNICAL SCIENCES Abstract Teorijska i eksperimentalna istraživanja provedena u okviru ovog rada odnose se na primjenu kemije i kemijskog inženjerstva te metodologije intenzifikacije procesa s ciljem razvoja naprednih fotokatalitičkih procesa. Cilj ovog rada je ispitati mogućnost intenzifikacije fotokatalitičkih procesa primjenom permanentnog magneta. Tijekom eksperimentalnog dijela rada praćena je fotokatalitička razgradnja izabranog neonikotinoidnog insekticida u vodenoj otopini u kojoj se nalazio suspendirani TiO2 fotokatalizator. Neodimijski magneti (NdFeB) kao najjači permanentni magneti, korišteni su s namjerom da se omogući učinkovita separacija nositelja naboja i poboljšanje ukupne učinkovitosti fotorazgradnje. Korišteni su magneti s različitim dimenzijama i gustoćama magnetskog toka na površini magneta (50x2,5 mm (0,20 T); 50x10 mm (0,34 T)). Kao modelna komponenta izabran je imidakloprid s obzirom da njegova intenzivna primjena predstavlja rizik i opasnost za vodeni okoliš, a samim time i za živa bića koja dolaze u doticaj s tako kontaminiranim vodenim izvorima. Fotokatalitička razgradnja imidakloprida provedena je u šaržnom reaktoru s kontroliranom i stalnom recirkulacijom reakcijske smjese i suspendiranog fotokatalizatora. Početna koncentracija imidakloprida u otopini iznosila je 10 ppm. Pripremljen je plan eksperimenata koji je uključivao tri parametra: prisutnost permanentnog magneta, odnosno vrijednost magnetskog toka na površini magneta (0 T, 2x0,20 T i 0,34 T), intenzitet zračenja (10 mW/cm^2, 30 mW/cm^2 i 50 mW/cm^2) i masa fotokatalizatora (1,0 mg, 3,0 mg i 5,0 mg). Kao fotokatalizator korišten je komercijalno dostupan praškasti TiO2P25 (Degussa/Evonik). Fotokatalitička razgradnja provedena je fotoaktivacijom pomoću UVA dijela elektromagnetskog spektra, a kao izvor zračenja korištene su UVA-LED lampe snage 30 W. Analiza produkata praćena je primjenom tekućinske kromatografije visoke djelotvornosti. Rezultati istraživanja pokazali su da intenzitet zračenja i masa fotokatalizatora najviše utječu na učinkovitost fotokatalitičke razgradnje imidakloprida. Nađeno je da konverzija imidakloprida raste s porastom intenziteta zračenja i mase fotokatalizatora. Ustanovljeno je da pri reakcijskim uvjetima i uz izvedbu fotoreaktora korištenog u ovom radu primjena permanentnih magneta nema značajan učinak na fotokatalitičku razgradnju imidakloprida.
Abstract (english) The theoretical and experimental investigations carried out in this work relate to the application of chemistry and chemical engineering and process intensification methodology to the development of advanced photocatalytic processes. The aim of this work is to investigate the possibility of intensification of photocatalytic processes by using a permanent magnet. During the experimental part of the work, photocatalytic degradation of the selected neonicotinoid insecticide was monitored in an aqueous solution with a suspended TiO2 photocatalyst. Neodymium magnets (NdFeB) were used as the strongest permanent magnets to enable effective separation of charge carriers and improve the overall photodegradation efficiency. Magnets with different dimensions and magnetic flux densities on their surface were used (50x2.5 mm (0.20 T); 50x10.0 mm (0.34 T)). Imidacloprid was chosen as a model component because its intensive application poses a risk and hazard to the aquatic environment, including living organisms that come into contact with such contaminated water sources. Photocatalytic degradation of imidacloprid was carried out in a batch reactor with controlled and constant recirculation of the reaction mixture and suspended photocatalyst. The initial concentration of imidacloprid in the solution was 10 ppm. The experimental design included three parameters: the presence of a permanent magnet, i.e., the value of magnetic flux on the surface of the magnet (0 T, 2x0.20 T, and 0,34 T), the radiation intensity (10,0 mW/cm^2, 30,0 mW/cm^2, and 50.0 mW/cm^2), and the mass of the photocatalyst (1.0 mg, 3.0 mg, and 5.0 mg). Commercially available powdered TiO2P25 (Degussa/Evonik) was used as the photocatalyst. Photocatalytic degradation was performed by photoactivation using the UVA part of the electromagnetic spectrum and UVA-LED lamps with a power of 30 W were used as the source. The analysis of the products was carried out by applying high performance liquid chromatography. The research results showed that the intensity of radiation and the mass of photocatalyst have the greatest influence on the efficiency of photocatalytic degradation of imidacloprid. It was found that the conversion increased with increasing radiation intensity and photocatalyst mass. It was also found that under the reaction conditions and power of the photoreactor used in this work, the use of permanent magnets had no significant effect on the photocatalytic degradation of imidacloprid.
Keywords
heterogena fotokataliza
neonikotinoidi
imidakloprid
permanentni magnet
titanijev(IV) oksid (TiO2)
intenzifikacija
dizajn eksperimenta
Keywords (english)
heterogeneous photocatalysis
neonicotinoids
imidacloprid
permanent magnet
titanium(IV) oxide (TiO2)
intensification
design expert
Language croatian URN:NBN urn:nbn:hr:149:188254 Project Number: IP-2018-01-8669 Study programme Title: Applied Chemistry - Graduate study; specializations in: Environmental chemistry and green technologies, Advanced materials and technologies, Applied organic chemistry Type of resource Text File origin Born digital Access conditions Access restricted to students and staff of home institution Terms of use Created on 2023-03-19 18:52:13
