Zmanjševanje emisij antibiotikov iz odpadnega blata z ozonacijo

Rovšek, Eva (author), Žgajnar Gotvajn, Andreja (mentor)

Anaerobna razgradnja je učinkovita metoda odstranjevanja onesnaževal iz odpadnih vod in ena izmed najpogosteje uporabljenih metod stabilizacije odvečnega blata bioloških čistilnih naprav. Mikroorganizmi razgradijo organske snovi pri anaerobnih pogojih, kjer sta prevladujoča produkta razgradnje metan (CH4) in ogljikov dioksid (CO2), torej bioplin, ki ga lahko izrabimo v energetske namene. Aktivno blato iz čistilne naprave in živalsko blato sta se izkazala za problematična substrata, saj vsebujeta nepredelane antibiotične učinkovine ali produkte njihove razgradnje. Antibiotiki in druge kemijske spojine lahko zavirajo delovanje mikroorganizmov, ki sodelujejo pri procesu anaerobne razgradnje in tako zmanjšajo produkcijo bioplina, torej energetsko izrabo odpadnega materiala. S poskusom določanja anaerobne razgradljivosti smo želeli določiti učinkovitost ozonacije za predobdelavo aerobnega blata, kontaminiranega s tremi različnimi antibiotiki (amoksicilin, tiamulin in levofloksacin). Ozonacija je ena izmed naprednih oksidacijskih procesov, s katerim lahko kompleksne organske molekule razgradimo v manjše in lažje razgradljive molekule. Namen raziskave je ugotoviti, če lahko z ozonacijo kontaminiranega aerobnega blata odpravimo zaviralne učinke antibiotikov na anaerobne mikroorganizme in obenem pridobimo zadostno količino bioplina. Ugotovili smo, da vsi trije antibiotiki v aerobnem blatu negativno vplivajo na anaerobno razgradnjo. Rezultati so pokazali, da ozonacija aerobnega blata prispeva k večji produkciji bioplina med njegovo obdelavo v anaerobnih pogojih, večjemu deležu CH4 v bioplinu in odpravi zaviralni učinek antibiotikov. Ob dodatku amoksicilina oz. tiamulina je prišlo do 20 % inhibicije produkcije bioplina, medtem ko je ob dodatku levofloksacina prišlo do 26 % inhibicije. Ozonacija je pri vseh treh vzorcih, kontaminiranih z antibiotiki, odpravila zaviralne učinke. V primerjavi z neozoniranim kontaminiranim aerobnim blatom se je količina bioplina po ozonaciji vzorca z amoksicilinom povečala za 74 %, pri vzorcu s tiamulinom za 69 % in pri vzorcu z levofloksacinom za 55 %. Prav tako smo ugotovili, da ozonacija aerobnega blata in kontaminiranega aerobnega blata poveča delež CH4 v bioplinu. V primerjavi z neozoniranim kontaminiranim aerobnim blatom se je delež CH4 po ozonaciji pri amoksicilinu povečal za 12 %, pri tiamulinu za 14 %, pri levofloksacinu pa za 18 %.

• Language: Slovenian
• Keywords: antibiotiki, bioplin, emisije, inhibicija, ozonacija
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2021
• PID: 20.500.12556/RUL-132406
• COBISS.SI-ID: 88630275
• Publication date in RUL: 25.10.2021

Secondary language

• Language: English
• Title: Reduction of emissions of antibiotics from waste sludge by ozonation

Abstract

Anaerobic digestion is an effective method of removing pollutants from wastewaters and one of the most frequently used methods for the stabilization of redundant biological treatment plant’s activated sludge. Microorganisms digest organic matter under the anaerobic conditions, producing mostly methane (CH4) and carbon dioxide (CO2) as by-products, named biogas, which can be used as an energy source. Activated sludge from the wastewater treatment plant and animal manure have proved to be problematic substrates, since they contain antibiotic substances and products of their degradation. Antibiotics and other chemical compounds can inhibit the activity of microorganisms involved in the process of anaerobic digestion and thus decrease the biogas production, consequently reducing the energy recovery from waste material. In this study, anaerobic digestion experiment was performed to determine the ozonation efficiency for the pre-treatment of anaerobic waste, contaminated with three different antibiotics (amoxicillin, tiamulin and levofloxacin). Ozonation is one of the advanced oxidation processes, which can break down complex organic molecules into smaller and more easily degradable molecules. The purpose of the thesis is to find out, if ozonation of contaminated aerobic sludge can be used to eliminate the inhibitory effects of antibiotics on anaerobic microorganisms and to assure the production of sufficient amounts of biogas. All three antibiotics had negative impact on the anaerobic digestion. The results showed that ozonation contributes to an increased production of biogas during anaerobic digestion, to an increased rate of CH4 in the biogas and eliminates the inhibitory effect of antibiotics. The addition of amoxicillin or tiamulin inhibited the biogas production by 20 %, while the addition of levofloxacin inhibited it by 26 %. In all three samples, contaminated with antibiotics, the ozonation eliminated the inhibitory effects. Compared to the non-ozonated contaminated aerobic sludge, the amount of biogas increased by 74 % after ozonation of the sample with amoxicillin, in the case of the sample with tiamulin by 69 % and in the case of the sample with levofloxacin by 55 %. We also found that ozonation increases the percentage of CH4 in the biogas. Compared to the non-ozonated contaminated active sludge, the percentage of CH4 after the ozonation increased by 12 % in the case of amoxicillin, by 14 % in the case of tiamulin and by 18 % in the case of levofloxacin.

• Keywords: antibiotics, biogas, emissions, inhibition, ozonation