Processes for treatment of antibiotic polluted hospital wastewater

Ostanki antibiotikov in drugih zdravil, postajajo vse resnejši problem, saj jih najdemo v izpustih iz farmacevtskih in proizvodnih obratov, bolnišnic in odplakah iz čistilnih naprav. Različne študije so pokazale, da so ostanki antibiotikov prisotni v odpadnih in površinskih vodah, zadnje študije pa kažejo trend zviševanja tudi v tleh, podtalnici ter pitni vodi. Čeprav so izmerjene koncetracije v širokem koncentracijskem območju od ng/L do µg/L, so lahko nekateri razgradni produkti aktivnih snovi celo bolj toksični kot izvorna snov. Predhodne študije so pokazale, da so najvišje koncentracije antibiotikov v bolnišničnih odpadnih vodah. Za odstranitev takšnih onesnaževal pa obstoječe čistilne naprave niso primerne, saj velike količine antibiotikov ostajajo v vodi tudi po čiščenju. V doktorski disertaciji so predstavljeni trije procesi odstranjevanja teh onesnaževal iz bolnišničnih odpadnih vod. Glavni namen je bil poiskati napredne, izvedljive metode za odstranitev izbranih antibiotikov iz bolnišnične odpadne vode. V prvem delu smo se osredotočili na postopek čiščenja s sub in super-kritično oksidacijo, kjer smo preučili procesne parametre: vpliv temperature, tlaka, pretoka in časa. V drugem delu smo opravili postopek ozonacije, kjer smo spremljali učinkovitost čiščenja odpadne vode s spreminjanjem pH vzorca, različnimi odmerki ozona ter dodatek vodikovega peroksida (H2O2). V tretjem delu smo za čiščenje sintetično pripravljene bolnišnične odpadne vode uporabi aerobni reaktor, kjer smo iskali optimalen bivalni čas. Vsebnost antibiotikov smo po vsaki metodi čiščenja določali z optimiranimi LC-MS/MS analiznimi tehnikami. V zadnjem delu doktorske disertacije smo vse omenjene postopke čiščenja implementirali na realnem vzorcu bolnišnične odpadne vode. Vsebnost antibiotika v realnem vzorcu pred in po čiščenju smo določali z ekstrakcijo na trdni fazi v povezavi z optimirano LC-MS/MS tehniko. Na koncu smo izvedli še test inhibicije porabe kisika z aktivnim blatom za oksidacijo ogljika in amonija, s katerim smo poskušali ugotoviti, toksičen vpliv očiščene vode na mikrooganizme v aktivnem blatu.The residues of antibiotics and other medicines are becoming an increasingly serious problem because they can be found in discharges from pharmaceutical and manufacturing plant, hospitals and sewage from treatment plants. Various studies showed that antibiotic residues are present in wastewaters and surface waters, and recent studies show an increase in ground water, drinking water and in the soil. Although the measured concentrations are in a wide range from ng/l to µg/l, some degradation products of the active substances may be even more toxic than the parent substance. Preliminary studies have shown that the highest concentrations of antibiotics are found in hospital wastewater. In order to remove such pollutants, existing treatment plants are not suitable, as large amounts of antibiotics remain in the water after cleaning. The doctoral dissertation presents three processes for removing these pollutants from hospital wastewater. The main purpose was to find advanced, feasible methods for the removal of selected antibiotics from hospital wastewater. In the first part, we focused on the process of purification with sub and super-critical oxidation, where we examined the process parameters: the influence of temperature, pressure, flow and time. In the second part, we carried out the ozonation process, where we monitored the efficiency of wastewater treatment by changing the pH of the sample, the different ozone doses, and the addition of hydrogen peroxide (H2O2). In the third part, the aerobic reactor was used to clean synthetically prepared hospital wastewater, where we were looking for an optimal residence time. The antibiotic content was determined after each purification method with optimized LC-MS/MS analytical techniques. In the last part of the doctoral dissertation, all the mentioned cleaning procedures were implemented on a realistic sample of hospital wastewater. The antibiotic content in the real sample before and after purification was determined by solid phase extraction in conjunction with the optimized LC-MS/MS technique. Finally, an oxygen consumption test with an activated sludge for the oxidation of carbon and ammonia was carried out, with which we attempted to determine the toxic effect of purified water on microorganisms in the active mud