Summary:
Pharmaceuticals and industrial chemicals are discharged into the aquatic
environment via wastewater treatment plants (WWTPs), where they are subjected
to microbial degradation. Studies have shown that different transformation
pathways can take place, resulting in the formation of transformation products
(TPs) that, to some extent, differ in their environmental behavior compared to
the parent compound. Therefore, it is crucial to investigate the
biotrasformation mechanism during the wastewater treatment. Due to their
widespread use, the studied compounds are important environmental pollutants
mainly addressed to the aquatic ecosystem. Recent studies indicate their
existence in both influent and effluent wastewater samples, classifying them in
the broader category of ‘emerging pollutants’. However, information and
research activity on the rate of removal and transformation during the
wastewater treatment is limited.
The goals of this thesis were to study the degradation kinetics and to identify
novel TPs of the pharmaceutical compounds ranitidine, lidocaine, citaloprame,
metformin, tramadol, ephedrine, furosemide, hydrochlothiazide and sweetener
cyclamate under aerobic, anoxic and anaerobic conditions treated with activated
sludge were investigated. Give the number of transformation products were
detected and identified through suspect screening with HR-MS techniques. More
specifically, the removal and sorption of the PC as well as the formation of
TPs were investigated by setting batch reactors seeded with activated sludge.
Finally, for the detection of TPs, the analysis was performed in broad band
collision induse dissociation (bbCID) mode suspect screening workflow was used
for the detection and identification of TPs, by creating a suspect list. The
suspect list was compiled with all the TPs that have already been published in
relevant degradation studies. In silico on-line free orediction tools such as
EAWAG-PPS and Bruker’s software Metabolite Predict were used for predicting
possible TPs of the compounds.
Keywords:
Emerging contaminants, Biodegradation, Aerobic/anoxic/anaerobic conditions, Transformation products, LC-QTOF-MS
