Uklanjanje farmaceutskih mikroonečišćivala

undergraduate thesis

• Title (english): Removal of pharmaceutical micropollutants
• Author: Josipa Dželalija
• Mentor: Ana Lončarić Božić (mentor)
• Committee member: Ana Lončarić Božić (predsjednik povjerenstva)
• Committee member: Hrvoje Kušić (član povjerenstva)
• Committee member: Šime Ukić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2017-09-18, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Interdisciplinary Technical Sciences; Environmental Engineering

Abstract

Problem onečišćenja vode sve je veći, uslijed globalnog industrijskog razvoja i povećanja stanovništva čime očuvanje ograničenih resursa pitke vode postaje jednim od glavnih zadataka čovječanstva. Znatan problem u očuvanju vodenih resursa i općenito ravnoteže ekosustava predstavljaju nova onečišćivala, prirodni i sintetski spojevi s razmjerno nepoznatim interakcijama u ekosustavima, koji se ne uspijevaju dostatno ukloniti konvencionalnim metodama obrade otpadnih voda. U nova onečišćivala ubrajaju se i farmaceutici, među koje spada i diklofenak (DCF), jedan od globalno najzastupljenijih nesteroidnih protuupalnih lijekova. DCF je detektiran u vodama diljem svijeta i predstavlja potencijalno opasan spoj u eksoustavima, pogotovo u kombinaciji s drugim farmaceuticima. Kao potencijalno rješenje nameću se napredni oksidacijski procesi, poglavito fotokatalitički procesi aktivirani Sunčevim zračenjem, svojom potencijalnom ekonomskom isplativošću. Jedan od potencijalno atraktivnih fotokatalizatora je TiO2-SnS2, koji objedinjava prednosti pojedinačnih TiO2 i SnS2 poluvodiča uz poboljšanje fotoaktivnosti pod vidljivim, odnosno Sunčevim zračenjem. U ovome radu istraživana je adsorpcija DCF-a na fotokatalitički film TiO2-SnS2 imobiliziran sol-gel metodom spin coatingom depozicijom na staklene pločice. Adsorpcijski fenomeni izuzetno su važni u području fotokatalize te mogu odigrati značajnu ulogu u optimizaciji procesa. Određena je točka nultog naboja, tj. pH PZC (engl. point of zero charge) pri pH 4,5 za TiO2-SnS2. Najveći adsorpcijski kapacitet qe = 34,57 mg (DCF) g^-1 (TiO2-SnS2) ostvaren je pri pH 4 u ispitivanim uvjetima, što je rezultat povoljnih elektrostatskih privlačenja između DCF-a te površine TiO2-SnS2. Adsorpcijski kapacitet zatim se drastično smanjuje povećanjem pH. Ravnotežna adsorpcija, tj. ravnotežno uklanjanje pri pH 4 ostvareno je nakon 90 min eksperimenta pri brzini tresilice od 90 o min^-1. Brzina adsorpcije može se opisati kinetikom pseudo-prvog reda pri istraživanim uvjetima, što je u slaganju s literaturnim podacima o adsorpciji drugih onečišćivala. Uklanjanje DCF-a ograničeno je prijenosom tvari.

Abstract (english)

Water pollution is an ever growing problem, due to global rapid industrial and population growth. Fresh water resources are limiting, and with deteriorating quality due to pollution the pressure is growing to find a solution to pollution problems. A significant cause for concern are contaminants of emerging concern, natural and artificial compounds with little know interactions with the ecosystem, which aren't adequately removed by conventional wastewater treatment technologies. Pharmaceuticals are considered to be among contaminants of emerging concern. Diclofenac (DCF) is one of the most common pharmaceuticals detected in water and is a great cause for concern in wastewater effluents. Current wastewater treatment technologies are inadequate for DCF removal. Advanced oxidation processes show promise for successful DCF removal, especially photocatalytic processes which offer significant economic advantages when harvesting solar irradiation. TiO2-SnS2 is considered to be a promising photocatalyst, combining advantages of both components and providing improved photocatalytic activity under solar irradiation. The aim of this study was to investigate DCF adsorption (removal) on immobilized TiO2-SnS2 films. Immobilized films were obtained by sping coating a sol-gel precursor on glass plates. Adsorption phenomena are of great importance in photocatalysis and are a key for process optimization. The point of zero charge (PZC) for TiO2-SnS2 was experimentally determined to be at pH 4.5. The highest equilibrium adsorption capacity of 34.57 mg (DCF) per g (TiO2-SnS2) was achieved at pH 4. Favorable electrostatic interactions occur at pH sub PZC, owing to positive surface charge of the photocatalyst attracting electronegative functional groups of DCF. However adsorption capacity is significantly reduced at pH > PZC, due to unfavorable surface interactions. Equilibrium adsorption (removal) was achieved at 90 min at pH 4 and shaker setting of 90 rpm. A good correlation at investigated pH was achieved when testing pseudo-first order kinetics, which is in accordance to expectations from literature. The kinetic rate of adsorption was limited by mass transfer in the reactor.

• Keywords: TiO2-SnS2; adsorpcija; uklanjanje; imobilizirani film; diklofenak
• Keywords (english): TiO2-SnS2; adsorption; removal; immobilized film; diclofenac
• Language: croatian
• URN:NBN: urn:nbn:hr:149:122437
• Study programme: Title: Environmental Engineering - Undergraduate study; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka ekoinženjerstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka ekoinženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2021-03-12 10:39:47