Title Utjecaj procesnih uvjeta na razgradnju neonikotinoida na TiO2/perlit fotokatalizatoru Title (english) Influence of process conditions on the degradation of neonicotinoids on TiO2/perlite photocatalyst Author Tea Kapustić 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 Defense date and country 2022-09-20, Croatia Scientific / art field, TECHNICAL SCIENCES Abstract Neonikotinoidni insekticidi su skupina pesticida koji se koriste kao proizvodi za suzbijanje štetnih insekata čija primarna hrana su biljke u uzgoju. Nakon primjene, pesticidi završavaju u površinskim ili podzemnim vodama jer se teže adsorbiraju na čestice tla. U vodama su relativno postojani te predstavljaju zdravstveni rizik za ljude i životinje pa ih je potrebno na adekvatan i siguran način ukloniti. Kao alternativa klasičnim postupcima obrade nameću se napredni oksidacijski procesi dok je jedan od tih procesa heterogena fotokataliza. Cilj ovog rada je istražiti fotokatalitičku razgradnju neonikotinoidnog insekticida imidakloprida u vodenoj otopini. Eksperimenti su provedeni u procesnoj posudi ('kadici') volumena 1L recirkulacijom reakcijske smjese volumena 500 mL uz primjenu UVA LED izvora zračenja pri konstantnom naponu od 32V pomoću heterogenog fotokatalizatora na bazi perlita kao nosača za TiO2 fotokatalizator. Prije provedbe eksperimenta napravljen je plan eksperimenta pomoću programskog paketa Design-Expert. Ispitivan je utjecaj intenziteta zračenja (5; 6,5; 8 mW/cm^2), recirkulacije (50; 150; 250 mL/min) i mase fotokatalizatora (1,5; 3; 4,5 g) na konverziju ispitivanog onečišćivala. Tijek razgradnje imidakloprida praćen je pomoću tekućinske kromatografije visoke djelotvornosti. Iz eksperimentalnih podataka dobivene su konverzije fotokatalitičke razgradnje te vrijednosti konstanta brzine reakcije prema predloženom Langmuir-Hinshelwood kinetičkom modelu te je izračunato srednje kvadratno odstupanje (RMSD) za svaki eksperiment. Uočeno je dobro slaganje modela i eksperimenta. Rezultati eksperimentalnog ispitivanja pokazali su da je najznačajniji parametar fotokatalitičke razgradnje, pri uvjetima korištenim u ovom radu, upravo masa fotokatalizatora. Najveća konverzija i najveća konstanta brzine kemijske reakcije zapažene su kod eksperimenata s najvećom ispitivanom masom fotokatalizatora (4,5 g), najvećom recirkulacijom (250 mL/min) pri srednjem intenzitetu zračenja (6,5 mW/cm^2, UVA LED 20W i 30W). Najlošija razgradnja onečišćivala zabilježena je za eksperiment sa najmanjom masom fotokatalizatora (1,5 g), najmanjim intenzitetom zračenja (5 mW/cm^2, UVA LED 2x20W), ali kod srednje korištene vrijednosti recirkulacije (150 mL/min).
Abstract (english) Neonicotinoid insecticides are a group of pesticides used to control insect pests whose main food is crops. The pesticides enter surface or groundwater after application because they are difficult to adsorb to soil particles. They are relatively persistent in water and pose a risk to human and animal health, so they must be removed in an appropriate and safe manner. Advanced oxidation processes are prescribed as an alternative to classical treatment processes, and one of these processes is heterogeneous photocatalysis. The aim of this work is to study the photocatalytic degradation of the neonicotinoid insecticide imidacloprid in an aqueous solution. The experiments were performed in a process vessel with a volume of 1L with recirculation of the reaction mixture with a volume of 500 mL using a UVA LED radiation source at a constant voltage of 32V with a heterogeneous photocatalyst based on perlite as a support for the TiO2 photocatalyst. Before performing the experiment, an experimental design was prepared using the Design-Expert software package. The influence of intensity (5; 6,5; 8 mW/cm^2), recirculation (50; 150; 250 mL/min) and photocatalyst mass (1,5; 3; 4,5 g) on the transformation of the tested pollutant was investigated. The course of degradation of imidacloprid was monitored by high performance liquid chromatography. From the experimental data, the photocatalytic degradation conversions and reaction rate constants were determined according to the proposed Langmuir-Hinshelwood kinetic model, and the root mean square deviation (RMSD) was calculated for each experiment. Good agreement was found between the model and experiment. The experimental test results showed that the most important parameter of photocatalytic degradation under the conditions used in this work is exactly the mass of the photocatalyst. The highest conversion and the highest rate constant of the chemical reaction were observed in the experiments with the highest tested mass of the photocatalyst (4.5 g), the highest recirculation (250 ml/min) at medium radiation intensity (6,5 mW/cm^2, UVA LED 20 W and 30 W). The worst pollutant removal was observed for the experiment with the smallest mass of the photocatalyst (1,5 g), the lowest radiation intensity (5 mW/cm^2, UVA LED 2x20W), but with the medium recirculation value (150 mL/min).
Keywords
neonikotinoidni insekticidi
imidakloprid
heterogena fotokataliza
perlit
titanijev (IV) oksid
DOE
Keywords (english)
neonicotinoid insecticides
imidaclopride
heterogeneous photocatalysis
perlite
titanium (IV) oxide
DOE
Language croatian URN:NBN urn:nbn:hr:149:737541 Project Number: IP-2018-01-8669 Study programme Title: Chemical Engineering - Graduate study Type of resource Text File origin Born digital Access conditions Closed access Terms of use Created on 2023-03-22 11:03:56
