Fotorazgradnja neonikotinoida na imobiliziranom fotokatalizatoru - određivanje reaktivnih vrsta

master's thesis

• Title (english): Photodegradation of neonicotinoids on immobilized photocatalyst - determination of reactive species
• Author: Tina Podreka
• Mentor: Vanja Kosar (mentor)
• Committee member: Vanja Kosar (predsjednik povjerenstva)
• Committee member: Vesna Tomašić (član povjerenstva)
• Committee member: Ana Lončarić Božić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2022-09-20, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Rast populacije dovodi do sve veće potrošnje pesticida s obzirom da imaju pozitivan učinak na zdravlje i kvalitetu života. Prilikom korištenja pesticida vrlo male količine dođu do ciljanih organizama, dok se većina rasipa u okoliš i onečišćuje sastavnice okoliša. Osim pozitivnih učinaka pesticidi imaju i negativan učinak na ekologiju i zdravlje populacije pa je njihovo izdvajanje iz okoliša, a pogotovo iz vodenih sustava vrlo poželjno. Otpadne vode se obrađuju biološkim, mehaničko-fizikalnim i kemijskim metodama u koje spavaju napredni oksidacijski procesi koji se nameću kao alternativa klasičnim postupcima. U napredne oksidacijske procese spada heterogena fotokataliza. U ovom radu istražena je fotokatalitička razgradnja imidakloprida u kotlastom reaktoru s recirkulacijom reakcijske smjese. Kao izvor fotoinducirane pobude fotokatalizatora korišteni su UVA-LED moduli snage 30 W, a kao fotokatalizator korišten je imobilizirani TiO2. Cilj ovog rada je određivanje reaktivnih vrsta kisika nastalih tijekom fotokatalitičke reakcije u koje spadaju superoksidni anionski radikal (O2∙−), vodikov peroksid (H2O2), singletni kisik (1O2) i hidroksilni radikal (OH∙). U tu svrhu korišteni su „hvatači“ koji imaju veliku reaktivnost s pojedinim kisikovim i ostalim reaktivnim vrstama. Dobiveno je da njihovim dodatkom dolazi do smanjenja fotokatalitičke razgradnje imidakloprida. Analizom rezultata zaključeno je da hidroksilni radikal, superoksidni anionski radikal i singletni kisik imaju važnu ulogu u mehanizmu fotokatalitičke razgradnje imidakloprida. Uz dodatak kalijevog persulfata dolazi do povećane fotokatalitičke razgradnje imidakloprida što je posljedica nastajanja sulfatnih radikala koji su jaka oksidacijska sredstva. Provedena je kinetička analiza uz pretpostavku da se reakcije opisuju kinetikom pseudo-prvog reda.

Abstract (english)

Population growth leads to an ever-increasing consumption of pesticides because they have a positive effect on health and quality of life. When using pesticides, very small amounts reach the target organisms, while the majority is wasted in the environment and pollutes the components of the environment. In addition to positive effects, pesticides also have a negative effect on the ecology and health of the population, so their removal from the environment, especially from water systems is highly desirable. Wastewater is treated with biological, mechanical-physical and chemical methods, which include advanced oxidation processes that are imposed as an alternative to classical procedures. Advanced oxidation processes include heterogeneous photocatalysis. This thesis investigated the photocatalytic decomposition of imidacloprid in a batch reactor with recirculation of the reaction mixture. UVA-LED modules with a power of 30 W were used as a source of photoinduced excitation of the photocatalyst and immobilized TiO2 was used as a photocatalyst. The aim of this work is to determine the reactive oxygen species formed during the photocatalytic reaction, which include superoxide anion radical (O2∙−), hydrogen peroxide (H2O2), singlet oxygen (1O2) and hydroxyl radical (OH∙). For this purpose "scavengers" were used, which have a high reactivity with certain oxygen and other reactive species. It was found that their addition reduces the photocatalytic degradation of imidacloprid. The results show that hydroxyl radical, superoxide anion radical and singlet oxygen play an important role in the mechanism of photocatalytic degradation of imidacloprid. With the addition of potassium persulfate, increased photocatalytic degradation of imidacloprid occurs, which is a consequence of the formation of sulfate radicals which are strong oxidizing agents. A kinetic analysis was performed assuming that the reactions are described by pseudo-first-order kinetics.

• Keywords: neonikotinoidi; imidakloprid; heterogena fotokataliza; TiO2; UVA-LED modul; hvatači; reaktivni kisikovi radikali
• Keywords (english): neonicotinoids; imidacloprid; heterogeneous photocatalysis; TiO2; UVA-LED module; scavengers; reactive oxygen radicals
• Language: croatian
• URN:NBN: urn:nbn:hr:149:950114
• Project: Number: IP-2018-01-8669; Title: Intenzifikacija fotokatalitičkih i katalitičkih procesa za obradu otpadnih voda i otpadnih plinova; Acronym: IN-PhotoCat; Leader: Vesna Tomašić; Jurisdiction: Croatia; Funder: HRZZ; Funding stream: IP
• Study programme: Title: Chemical Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka kemijskog inženjerstva (magistar/magistra inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2023-03-23 10:15:27