Encimska razgradnja ciprofloksacina v odpadnih vodah

magistrsko delo

Laura Prša (Author), Mateja Primožič (Mentor), Maja Leitgeb (Co-mentor)

Abstract

Antibiotiki so protibakterijske učinkovine, ki se uporabljajo v humani in veterinarski medicini, v živinoreji ter kot pospeševalci rasti. Približno 70 % vseh uporabljenih antibiotikov lahko v okolju odkrijemo nespremenjenih. Nepresnovljeni antibiotiki se pogosto prenašajo v vodno okolje z odpadnimi vodami. Zaskrbljujoči problem je, da lahko nenehna izpostavljenost antibiotikom povzroči nastanek ali obstoj protibakterijske odpornosti, zato so potrebne učinkovite tehnike za izboljšanje čiščenja odpadnih voda. Ciprofloksacin (CIP) je biološko nerazgradljiv antibiotik, ki ga najdemo v odplakah čistilnih naprav v koncentracijah do 5,6 μg/L. Encimski procesi predstavljajo učinkovito možnost za razgradnjo antibiotikov zaradi številnih prednosti kot so enostavni postopki, manjša poraba energije, uporaba v širokem območju pH-ja, odsotnost toksičnih učinkov ter visoka specifičnost na določen substrat. Prisotnost mediatorjev poveča oksidativno sposobnost lakaze, ki tako oksidira te mediatorje v proste radikale in omogoči zelo učinkovito odstranjevanje širokega spektra spojin. Magistrsko delo prikazuje študijo razgradnje antibiotika CIP s pomočjo encima lakaze. Proučevali smo degradacijo CIP ob prisotnosti lakaze ter mešanja z uporabo različnih tehnik; z ultrazvočnimi valovi, stresanjem s stresalnikom in mešanjem z magnetnim mešalom. Prav tako smo izvedli študijo vpliva dodanega mediatorja, kjer smo encimu lakazi dodali mediatorja siringaldehid (SA) ali 2,2-azino-bis(3-etilbenzotiazolin-6-sulfonsko kislino) (ABTS). Optimirali smo več procesnih parametrov, ki vplivajo na razgradnjo CIP. Najvišjo stopnjo razgradnje CIP smo dosegli z lakazo koncentracije 0,2 mg/mL in naravnim mediatorjem SA koncentracije 2 mM, kjer smo dosegli kar 94 % razgradnjo CIP po 48 h reakcije. Dodatek mediatorja SA je povzročil intenzivnejšo razgradnjo CIP z lakazo, prav tako pa je skrajšal čas razgradnje.

Keywords

ciprofloksacin;odpadne vode;degradacija;lakaza;HPLC;ABTS;SA;magistrske naloge;

Data

Language:	Slovenian
Year of publishing:	2021
Typology:	2.09 - Master's Thesis
Organization:	UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher:	[L. Prša]
UDC:	628.35:577.15(043.2)
COBISS:	93430787
Views:	132
Downloads:	54
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Enzymatic degradation of ciprofloxacin in wastewater
Secondary abstract:	Antibiotics are antibacterial agents used in human and veterinary medicine, in livestock production and as growth promoters. Approximately 70% of the antibiotics used, can be detected unchanged in the environment. Unmetabolised antibiotics are often transferred to the aquatic environment through wastewater. A worrying problem is that constant exposure to antibiotics can lead to the emergence or existence of antibacterial resistance, therefore effective techniques are needed to improve wastewater treatment. Ciprofloxacin (CIP) is a non-biodegradable antibiotic found in wastewater treatment plant sewage, at levels up to 5.6 μg/L. Enzymatic processes present an effective option for the degradation of antibiotics due to many advantages, such as simple procedures, lower energy consumption, use in wide range of pH, the absence of toxic effects and high specificity to a particular substrate. The presence of mediators increases the oxidising capacity of laccase, which oxidises these mediators into free radicals and allows a very efficient removal of a wide range of compounds. This master's thesis presents a study of the degradation of the antibiotic CIP using the enzyme laccase. CIP degradation with concomitant use of laccase and different mixing techniques; ultrasound, shaking, or mixing with a magnetic stirrer was performed. The effect of the added mediator, syringaldehyde (SA) and 2,2-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) was also studied. Several process parameters that affect CIP deterioration were optimized. The highest rate of CIP degradation was achieved with laccase at a concentration of 0.2 mg/mL and natural SA mediator at a concentration of 2 mM, where 94% CIP degradation was achieved after 48 h of reaction. The addition of the SA mediator resulted in a more intensive CIP degradation by laccase, and it also shortened the degradation time.
Secondary keywords:	ciprofloxacin;wastewater;degradation;lacasse;HPLC;ABTS;SA;
Type (COBISS):	Master's thesis/paper
Thesis comment:	Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages:	1 spletni vir (1 datoteka PDF (XI, 59 f.))
ID:	13963208