magistrsko delo
Teja Antončič (Author), Andreja Žgajnar Gotvajn (Mentor), Polona Žnidaršič Plazl (Thesis defence commission member), Janez Cerkovnik (Thesis defence commission member)

Abstract

Razširjena uporaba antibiotikov je povzročila, da se njihov obseg v okolju dnevno globalno povečuje. Antibiotiki se v telesu ne presnovijo v celoti. Večina antibiotikov se v okolje vnese preko živali, saj se v veterini uporabljajo kot zdravstvena preventiva, za zdravljenje bakterijskih okužb, z namenom pospeševanja rasti in/ali prirasta živali, preostanek pa v okolje vnesemo ljudje, zaradi zdravljenja bakterijskih okužb. Vnos antibiotikov v okolje neposredno najbolj vpliva na vodne organizme, predvsem pa je vse bolj skrb vzbujajoč pojav odpornih bakterij oz. superbakterij. Te bakterije so odporne proti antibiotikom in posledično nanje antibiotiki ne delujejo več, zato je vse več še pred kratkim preprosto ozdravljivih bakterijskih okužb težje ozdravljivih oz. neozdravljivih. Odstranjevanje antibiotikov je torej nujno. Zaradi vstopa večine antibiotikov v vodno okolje, se osredotočamo predvsem na odstranjevanje iz odpadnih vod. Konvencionalne komunalne čistilne naprave antibiotikov niso sposobne odstraniti in posledično lahko ti preprosto vstopijo v površinske vode, podtalnico in tudi pitno vodo. Za odstranjevanje antibiotikov iz odpadnih vod se vse bolj uporabljajo napredni oksidacijski procesi. Namen magistrske naloge je bil primerjava različnih naprednih oksidacijskih procesov za čiščenje odpadnih vod, ki vsebujejo antibiotike in preveritev, ali so ti postopki primerni za odstranjevanje antibiotikov iz vodnega okolja. Preučevali smo naslednje tehnike oz. postopke: direktna ozonacija, ozonacija pri povišanem pH (pH=9,5), ozonacija pri povišanem pH (pH=9,5) ob dodatku H2O2, ozonacija, katalizirana z dodatkom Fe2+, ozonacija, katalizirana z dodatkom Fe2+ in UV svetlobe, ozonacija s Fentonovo oksidacijo in ozonacija s foto-Fentonovo oksidacijo. Učinkovitost tehnik smo ovrednotili s spremljanjem celotnega organskega ogljika (TOC) in kemijske potrebe po kisiku (KPK). Ugotovili smo, da pri vseh postopkih proces poteče dvostopenjsko z bolj učinkovito prvo stopnjo procesa. Direktna ozonacija se je izkazala za najmanj učinkovito od vseh preučevanih postopkov, tako glede na TOC, kot KPK rezultate. Učinkovitost ozonacije se je povečala ob povišanem pH, ob dodatku UV, H2O2 in/ali katalizatorjev. Najučinkovitejša je bila ozonacija s foto-Fentonovo oksidacijo, s katero smo dosegli med 83 in 96 % stopnjo oksidacije prisotnih antibiotikov, ter med 65 in 84 % stopnjo mineralizacije, torej popolno razgradnjo antibiotikov v anorganske komponente, CO2 in H2O. S tem smo potrdili, da so napredni oksidacijski procesi primerni postopki za odstranjevanje antibiotikov iz odpadnih vod.

Keywords

antibiotiki;odpadne vode;napredni oksidacijski procesi;ozonacija;odporne bakterije;odpornost proti antibiotikom;magistrska dela;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL FKKT - Faculty of Chemistry and Chemical Technology
Publisher: [T. Antončič]
UDC: 628.349:66.094.3-926.214(043.2)
COBISS: 72155395 Link will open in a new window
Views: 325
Downloads: 83
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Other data

Secondary language: English
Secondary title: Optimization of ozone-based oxidation processes for degradation of antibiotics
Secondary abstract: The widespread use of antibiotics has been causing increase of their extent in the environment. Antibiotics are not completely metabolised in the body. Most antibiotics come into the environment through animals, as they are used in the veterinary medicine for health prevention, for the treatment of bacterial infections, with the purpose to promote growth and/or animal increment. The rest come to the environment because of human consumption, due to the treatment of bacterial infections. Antibiotics into the environment directly affect the aquatic organisms, and above all, the increasing concern arouses phenomenon of resistant bacteria or superbacteria. These bacteria are resistant to antibiotics and, consequently, they are not affected by them, so nowadays more and more bacterial infections are more difficult to be cured or are even incurable. Therefore, the removal of antibiotics is necessary. Due to the entry of most antibiotics in the aquatic environment, their removal from wastewater is the most important. Conventional municipal wastewater treatment plants are not capable of removing antibiotics and thus they can easily enter surface water, groundwater, and even drinking water. The main focus nowadays is the addition of the tertiary cleaning using advanced oxidation processes. The purpose of this thesis was to compare the various advanced oxidation processes for wastewater treatment containing antibiotics and verification if these procedures are suitable for the removal of antibiotics from the aquatic environment. We studied the following experimental techniques/procedures: direct ozonation, ozonation at elevated pH (pH = 9.5), ozonation at elevated pH (pH = 9.5) at the addition of H2O2, catalysed ozonation by addition of Fe2+, catalysed ozonation by addition of Fe2+ and UV light, ozonation with Fenton oxidation and ozonation with photo-Fenton oxidation. The methods were evaluated according to the total organic carbon (TOC) and chemical oxygen demand (COD). It can be concluded that studied procedures occur in two phases with first stage of process to be more effective. Direct ozonation was the least effective in terms of TOC, as well as COD. The efficiency of the ozonation increased at elevated pH, with the addition of UV, H2O2 and/or catalysts. The most effective procedure was ozonation with photo-Fenton oxidation, where we achieved between 83 and 96% oxidation of the present antibiotics and between 65 and 84% mineralization, hence the complete decomposition of antibiotics into inorganic components, CO2, and H2O. Our results confirmed that advanced oxidation processes are appropriate for removing antibiotics from wastewater.
Secondary keywords: advanced oxidation processes;antibiotics;antimicrobial resistance;ozonation;resistant bacteria;
Type (COBISS): Master's thesis/paper
Study programme: 1000376
Embargo end date (OpenAIRE): 1970-01-01
Thesis comment: Univ. v Ljubljani, Fak. za kemijo in kemijsko tehnologijo, smer Kemijsko inženirstvo
Pages: 64 str.
ID: 13119789