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Naraščajoča uporaba antibiotikov in vse večja prisotnost farmacevtskih učinkovin v odpadnih vodah pomenijo vse resnejši okoljski problem. Ker se antibiotiki v telesu ne presnovijo popolnoma, jih večina konča v okolju, saj jih konvencionalne čistilne naprave niso zmožne popolnoma odstraniti. Poleg ljudi so pomemben vir onesnaženja tudi veterina, farmacevtska industrija, bolnišnice in raziskovalne dejavnosti. Antibiotiki se v okolju nahajajo v majhnih koncentracijah in zaradi svojega stalnega vnosa lahko negativno vplivajo tako na vodne organizme kakor tudi na ljudi. V okviru magistrskega dela sta predstavljena dva napredna oksidacijska procesa in njuna kombinacija za odstranjevanje antibiotika iz odpadnih vod. Antibiotik amoksicilin smo želeli odstraniti z ozonacijo, hidrodinamsko kavitacijo ter njuno kombinacijo. Postopke smo izvajali pri različnih pretokih ozona in različnih koncentracijah amoksicilina. Učinkovitost procesov smo spremljali z določanjem celotnega organskega ogljika (TOC) in kemijske potrebe po kisiku (KPK). Z respirometrijo aktivnega blata pa smo spremljali biorazgradljivost antibiotika. Rezultati so pokazali, da je sama ozonacija najučinkovitejši proces, saj smo dosegli največje učinkovitosti razgradnje – glede na TOC 26 % in glede na KPK 62 %. S hidrodinamsko kavitacijo nismo dosegli želenega učinka, saj so bile učinkovitosti najmanjše – glede na TOC < 1 %, glede na KPK pa 20 %. Kombinacija obeh postopkov pa je dala enake učinkovitosti kakor sam proces ozonacije. Z respirometrijo aktivnega blata smo dokazali, da neobdelan antibiotik tudi po kavitaciji ni biorazgradljiv. Le proces ozonacije in kombinaicija ozonacije ter kavitacije sta antibiotik vsaj delno razgradila in povečala njegovo biorazgradljivost. The increasing use of antibiotics and the presence of pharmaceutical residues in wastewater is becoming a serious environmental problem. Studies show that most of consumed antibiotics are not metabolized in the body. Conventional wastewater treatment plants are not able to completely remove them so they are constantly excreted into the environment. In addition to humans, an important source of antibiotics in effluents are also veterinary medicine, pharmaceutical industry, hospitals and research facilities. Antibiotics are found in low concentrations in the environment because of their continuous discharge they are a potential threat on aquatic organisms as well as humans. Within the master's thesis, two advanced oxidation processes and their combination for the removal of antibiotics from wastewater are presented. We studied ozonation, hydrodynamic cavitation and their combination. The processes were performed at different ozone flows and different concentrations of amoxicillin. The efficiency of the processes was monitored with determination of total organic carbon (TOC) and chemical oxygen demand (COD). Biodegradability of antibiotic was evaluated with respirometry of activated sludge. The results showed that ozonation itself is the most efficient process, as we achieved the highest decomposition efficiencies in terms of TOC 26 % and COD 62 %. Hydrodynamic cavitation did not achieve the preferred effect as the efficiencies were the lowest, according to the TOC < 1% and COD 20 %. The combination of both processes, however, gave the same results as the ozonation process itself. Respirometry of activated sludge proved that the untreated antibiotic is not biodegradable even after cavitation. Only the process of ozonation and the combination of ozonation and cavitation at least partially degraded the antibiotic, and increased its biodegradability. |
