Primerjava katalitske in nekatalitske ozonacije za odstranjevanje antibiotikov iz odpadnih voda

Urbanc, Teja (author), Žgajnar Gotvajn, Andreja (mentor)

Kakovost življenja se z razvojem tehnologije izboljšuje in k temu močno pripomore tudi farmacevtska industrija, ki razvija vedno več farmacevtskih učinkovin. S tem pa se tudi povečuje količina antibiotikov v okolju, predvsem v vodnem okolju. To predstavlja potencialno nevarnost za organizme, še posebej za razvoj bakterij, ki so odporne na antibiotike. Izkazalo se je, da za čiščenje odpadnih vod, v katerih se nahajajo antibiotiki, ne zadostujejo le konvencionalni postopki čiščenja. V ta namen se vedno pogosteje uporabljajo napredni oksidacijski postopki. V okviru magistrskega dela smo primerjali in optimizirali katalitske in nekatalitske tehnike ozonacije za odstranjevanje dveh izbranih antibiotikov iz odpadnih voda. Preučevali smo neposredno ozonacijo, posredno ozonacijo pri povišanem pH, posredno ozonacijo z dodatkom H2O2, katalitsko ozonacijo, foto-katalitsko ozonacijo, ozonacijo s Fentonovo oksidacijo in ozonacijo s foto-Fentonovo oksidacijo. Tekom raziskovalnega dela smo primerjali učinkovitosti razgradnje antibiotika amoksicilin in levofloksacin ter poskušali ugotoviti vpliv temperature na katalitske in nekatalitske procese ozonacije. Vse procese smo izvajali pri sobni (21 °C) in povišani (40 °C) temperaturi, da smo lahko določili temperaturno odvisnost kinetike procesa z določitvijo Arrheniusovih parametrov. Razgradnjo antibiotikov smo spremljali z določevanjem celotnega organskega ogljika (TOC) in kemijske potrebe po kisiku (KPK). Ugotovili smo, da pri vseh ozonacijah poteče dvostopenjska reakcija, kjer prva stopnja poteče hitreje in je v večini poskusov ozonacij bolj učinkovita v primerjavi z drugo stopnjo. Ob primerjavi učinkovitosti ozonacij glede na temperaturo se je v večini primerov izkazalo, da le-ta poteče hitreje pri povišani temperaturi v primerjavi s sobno temperaturo. Popolne mineralizacije ne moremo potrditi pri nobenem tipu ozonacije, saj učinkovitosti razgradnje antibiotika glede na TOC niso presegle 85 %. Glede na TOC in KPK rezultate lahko sklepamo, da je v večji meri potekla razgradnja antibiotika v stranske produkte. Na podlagi pridobljenih rezultatov lahko ugotovimo, da sta se za najbolj uspešna tipa ozonacij izkazala ozonacija s foto-Fentonovo oksidacijo ter posredna ozonacija pri povišanem pH in dodatkom H2O2.

• Language: Slovenian
• Keywords: amoksicilin, levofloksacin, napredni oksidacijski postopki, ozonacija
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2022
• PID: 20.500.12556/RUL-136242
• COBISS.SI-ID: 105540355
• Publication date in RUL: 21.04.2022

Secondary language

• Language: English
• Title: Comparison of catalytic and non-catalytic ozonation for the removal of antibiotics from wastewater

Abstract

The quality of life is increasing with the development of new technologies. Pharmaceutical industry is very important in that regard as it makes large quantities of pharmaceutical products. On the other hand, concentrations of antibiotics are increasing in every environment especially in water ecosystems. This poses a great risk for organisms as well as it supports development of the antibiotic resistance genes in bacteria. It has been shown that conventional processes are not sufficient for treatment of wastewaters that contain antibiotics. That’s why there has been an increasing interest in advanced oxidation possesses for removing antibiotics form wastewaters. The aim of this research was to compare and optimise catalytic and non-catalytic ozonation for removal of two antibiotics from wastewaters. Direct ozonation, indirect ozonation at elevated pH, indirect ozonation with the edition of hydrogen peroxide, catalysed ozonation, photocatalytic ozonation, ozonation with Fenton oxidation and ozonation with photo-Fenton oxidation were compared for degradation of amoxicillin and levofloxacin. The effect of temperature dependence was also studied. All types of ozonation’s were carried out at room temperature (21°C) and at increased temperature (40°C). We consequently assessed the temperature dependence of kinetic process by calculating Arrhenius parameters. Degradation of antibiotics was monitored by measurement of total organic carbon (TOC) and chemical oxygen demand (COD). All types of ozonation proceeded in two stages. The first step was faster and more effective than the second one while comparing the efficiency at different temperatures. The degradation proceeded faster at higher temperatures. None of the samples was fully mineralised - TOC efficiency reached up to 85%. Based on TOC and COD results it can be concluded that the most effective types of ozonation are ozonation combined with photo-Fenton oxidation and direct ozonation at elevated pH with the addition of hydrogen peroxide.

• Keywords: Advanced Oxidation Process, Amoxicillin, Levofloxacin, Ozonation