Supervisors info:
Θωμαΐδης Νικόλαος, Καθηγητής, Τμήμα Χημείας, Εθνικό και Καποδιστριακό Πανεπιστήμιο Αθηνών
Summary:
Modern sanitary processes result in large volumes of human waste, as well as domestic and industrial sewage, being collected and treated at common collection points, wastewater treatment plants. A wide range of organic compounds is used in modern societies which end up to the WWTPs and consequently to the liquid effluent and sewage sludge. For this reason, it is critical to evaluate the presence and risk of emerging pollutants in such samples.
This thesis reports the target screening of emerging pollutants in sewage sludge samples collected in 2015 from three WWTPs from Nigeria (Iponri, Alausa, Ijaiye). An ultrasound assisted extraction was used for the sample preparation and the exracts were analyzed with reversed-phase liquid-chromatography coupled to quadrupole-time-of-flight mass spectrometry (RP)LC-QTOF-MS and the data were acquired through broad-band Collision Induced Dissociation (bbCID) mode, which provided information on parent and fragment ions without pre-selection of analytes in one run. Validation was performed based on representative compounds of the wide-scope screening method. A database of approximately 2500 compounds was used for target screening and the detection was based on retention time, mass accuracy, isotopic pattern and fragmentation products.
Following the aforementioned procedures, 182 compounds were identified including pharmaceutical drugs, pesticides, illicit drugs, industrial chemicals and other classes of compounds. The target screening revealed the profile of each WWTP and the differences between the analytes after the stage of digestion and the secondary treatment.
Keywords:
Emerging Pollutants, Sewage Sludge, Target Screening, LC-QTOF-MS, Nigeria
