| الوصف: |
U današnje vrijeme upotreba ksenobiotika sve je češća, a samim time se i sve veće količine nekontrolirano ispuštaju u okoliš. Pesticidi, antiparazitici te ostali ksenobiotici i njihovi metaboliti, razgradni i transformacijski produkti dospijevaju u tlo i vodu čineći štetu biljnom i životinjskom svijetu. Kako su ksenobiotici spojevi složene kemijske strukture, vrlo ih je teško u potpunosti ukloniti iz vode, a često je potrebno korištenje složenih i skupih metoda obrade otpadnih voda. Metode obrade aktivnim muljem najzastupljenije su metode u obradi otpadnih voda. Cilj ovoga rada je ispitati mogućnosti uklanjanja ksenobiotika iz otpadnih voda biorazgradnjom pomoću aktivnog mulja. Određivana je mogućnost biorazgradnje antiparazitika febantela, albendazola i mebendazola te pesticida iz skupine insekticida tiakloprida, acetamiprida i klotianidina u vremenu od 48 sati tekućinskom kromatografijom visoke djelotvornosti uz praćenje pH-vrijednosti, temperature, gustoće, ukupne količine ugljika te utjecaja na mikroorganizme. Proces biorazgradnje odvijao se u pet reaktora koji su bili zaštićeni aluminijskom folijom kako bi se spriječio utjecaj Sunčeve svjetlosti na razgradnju ksenobiotika. Uklanjanje ksenobiotika određivano je tekućinskom kromatografijom visoke djelotvornosti uz detektor s nizom dioda, a uzorci su se uzimali u točno određenim vremenskim intervalima. Uz to, uzorci su se analizirali i mjerenjem ukupne količine ugljika, a pratili smo i gustoću aktivnog mulja prije procesa biorazgradnje te gustoću nakon biorazgradnje i to za reaktor s muljem, mikroplastikom i ksenobiotikom te za reaktor s muljem i ksenobiotikom. Također je za svaki ksenobiotik provedena i mikrobiološka analiza kako bi se utvrdio utjecaj pojedinog ksenobiotika na mikroorganizme koji sudjeluju u procesu biorazgradnje. Stopostotno uklanjanje postignuto je za sve antiparazitike, dok je kod pesticida uklanjanje bilo nešto lošije. Uz sam proces uklanjanja uzimala se u obzir i adsorpcija i desorpcija komponenata na površinu mikroplastike i pahuljice aktivnog mulja, a pomoću dobivenih kromatograma detektirali su se i razgradni/transformacijski produkti koji nastaju tijekom procesa biorazgradnje. Nowadays, the use of xenobiotics is becoming more and more common, and thus increasing amounts are being released into the environment in an uncontrolled manner. Pesticides, antiparasitics and other xenobiotics and their metabolites, degradation and transformation products reach the soil and water causing damage to the plant and animal life. Since xenobiotics are compounds with a complex chemical structure, it is very difficult to completely remove them from water, and it is often necessary to use complex and expensive wastewater treatment methods. Activated sludge treatment methods are the most common methods in wastewater treatment. The aim of this work is to examine the possibilities of removing xenobiotics from wastewater by biodegradation using activated sludge. The possibility of biodegradation of the antiparasitics febantel, albendazole and mebendazole and pesticides from the group of insecticides thiacloprid, acetamiprid and clothianidin was determined within 48 hours by high-performance liquid chromatography with monitoring of pH-value, temperature, density, total carbon and impact on microorganisms. The biodegradation process took place in five reactors that were protected by aluminum foil to prevent the influence of sunlight on the degradation of xenobiotics. The removal of xenobiotics was determined by high-performance liquid chromatography with a diode array detector, and samples were taken at precisely determined time intervals. In addition, the samples were analyzed by measuring the total amount of carbon, and we monitored the density of activated sludge before the biodegradation process and the density after biodegradation for the reactor with sludge, microplastics and xenobiotics and for the reactor with sludge and xenobiotics. A microbiological analysis was also carried out for each xenobiotic in order to determine the influence of each xenobiotic on the microorganisms that participate in the biodegradation process. One hundred percent removal was achieved for all antiparasitics, while the removal was slightly worse for pesticides. In addition to the removal process itself, the adsorption and desorption of components on the surface of microplastics and activated sludge flakes were also taken into account, and the resulting chromatograms were used to detect the degradation/transformation products that arise during the biodegradation process. |
