Vpliv ozoniranja na učinkovitost anaerobne obdelave z antibiotiki onesnaženega odpadnega aktivnega blata

Škedelj, Matjaž (author), Žgajnar Gotvajn, Andreja (mentor)

Velika količina blata, ki nastane med biološkim čiščenjem odpadnih vod, predstavlja enega izmed glavnih problemov čistilnih naprav. Odlaganje oziroma ustrezna obdelava odpadnega aktivnega blata predstavlja do 65 % celotnih obratovalnih stroškov čistilne naprave. Ker odpadna voda predstavlja enega izmed glavnih virov antibiotikov v okolju, obstaja verjetnost, da se antibiotiki zaradi svoje kompleksne strukture v procesu biološkega čiščenja ne razgradijo popolnoma. Tako se lahko del antibiotikov v nespremenjeni obliki vrne nazaj v okolje, del pa se jih lahko adsorbira na odpadno aktivno blato, ki ga kasneje uporabimo kot substrat pri anaerobni obdelavi in produkciji bioplina. Antibiotiki v odpadnem aktivnem blatu inhibirajo produkcijo bioplina, saj svojim prisotnostjo omejijo aktivnost anaerobnih mikroorganizmov. Zato je potrebno odpadno aktivno blato pred vstopom v anaerobno obdelavo ustrezno obdelati. Pri anaerobni obdelavi kot stranska produkta nastaneta metan, ki predstavlja vir obnovljive energije in ogljikov dioksid. Med vsemi tehnikami naprednih oksidacijskih procesov se je ozonacija blata izkazala za uspešno metodo zmanjšanje inhibicije produkcije bioplina, ki je bila posledica onesnaženosti z antibiotiki. Ozon je močan oksidant, ki se veliko uporablja pri čiščenju odpadnih vod in obdelavi odpadnega aktivnega blata. Med obdelavo blata se ozon hitro pretvori v radikale in nastali radikali vplivajo na oksidacijo tako trdih delcev kot topnih organskih snovi. Med različnimi naprednimi oksidacijskimi procesi je obdelava z ozonom še posebej pomembna, ker po oksidaciji ni prisotnih oksidativnih ostankov, hkrati pa se koncentracija anorganskih soli ne poveča. V sklopu magistrskega dela smo preučili vpliv ozoniranja na učinkovitost anaerobne obdelave z antibiotiki kontaminiranega odpadnega aktivnega blata. Izvajali smo proces ozonacije aerobnega blata onesnaženega s tremi različnimi antibiotiki (tiamulinom, amoskicilinom in levofloksacinom). Ugotovili smo, da prisotnost katerega koli preiskovanega antibiotika povzroči inhibicijo produkcije bioplina, ki smo jo odpravili z 20 minutno ozonacijo kontaminiranega aerobnega blata. Po ozonaciji kontaminiranega aerobnega blata se je količina nastalega bioplina povečala od 20 do 36% v primerjavi s kontaminiranim aerobnim blatom. Prav tako se je povečal delež metana v bioplinu ozoniranega kontaminiranega aerobnega blata od 16 do 40 % v primerjavi z kontaminiranim aerobnim blatom.

• Language: Slovenian
• Keywords: anaerobna obdelava, antibiotik, bioplin, odpadno aktivno blato, 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-133649
• COBISS.SI-ID: 89969411
• Publication date in RUL: 07.12.2021

Secondary language

• Language: English
• Title: Impact of ozonation on efficiency of anaerobic digestion of antibiotic-containing waste activated sludge

Abstract

The large amount of sludge generated during biological wastewater treatment is one of the main problems of a biological treatment. Disposal or the appropriate treatment of waste activated sludge represents up to 65% of the total operating costs of the treatment plant. Wastewater is one of the main sources of antibiotics in the environment. Therefore, it is likely that antibiotics are not completely degraded in the biological treatment process due to their complex structure. Thus, some of the antibiotics can be returned unchanged to the environment, and some can be adsorbed to waste activated sludge, which is later used as a substrate in anaerobic digestion and biogas production. Antibiotics in waste activated sludge inhibit biogas production by limiting the activity of anaerobic microorganisms. Consequently, waste activated sludge needs to be properly processed before entering anaerobic digestion. Anaerobic digestion produces by-products methane, which is a source of renewable energy, and carbon dioxide. Among all advanced oxidation process techniques, sludge ozonation has shown to be a successful method for the reduction of the inhibition of biogas production due to antibiotic contamination. Ozone is a powerful oxidant that is widely used in wastewater treatment and waste activated sludge treatment. During sludge treatment, ozone is rapidly converted into radicals, which affect the oxidation of both solid particles and soluble organic matter. Among the various advanced oxidation process techniques, ozone treatment is particularly important because no oxidative residues are present after oxidation, and at the same time, the inorganic salts concentration does not increase. As part of the master's thesis, we examined the effect of ozonation on the effectiveness of anaerobic treatment with antibiotics of contaminated waste activated sludge. We performed the process of ozonation of aerobic sludge contaminated with three different antibiotics (tiamulin, amoxicillin and levofloxacin). We found that the presence of any model antibiotic caused inhibition of biogas production, which was eliminated by 20 minutes of ozonation of contaminated aerobic sludge. After ozonation of contaminated aerobic sludge, the amount of biogas produced increased from 20% to 36% compared to contaminated aerobic sludge. The proportion of methane in the biogas of ozonated contaminated aerobic sludge also increased from 16% to 40% compared to the sample of contaminated aerobic sludge.

• Keywords: anaerobic digestion, antibiotic, biogas, ozonation, waste activated sludge