Electronic Thesis and Dissertation Repository

Degree

Doctor of Philosophy

Program

Civil and Environmental Engineering

Supervisor

Dr. Ernest K. Yanful

Abstract

This study concentrates on the identification and quantification of three pharmaceutical compounds (ibuprofen, naproxen and diclofenac) and an endocrine disrupting compound (17α-ethinylestradiol) in wastewater effluents collected from Adelaide Wastewater Treatment Plant and Greenway Pollution Control Plant, London, ON, Canada. For sample preparation, both solid-phase extraction and liquid-liquid extraction techniques were followed and GC-FID and LC-MS were used for sample analysis. Although the target pharmaceuticals were present in the wastewater samples at concentrations in a range of 0.29-8.98 µ/L, 17α-ethinylestradiol was not detected.

For eradicating or removing the above-mentioned organic compounds from water, organic solvent nanofiltration (OSNF) membrane was used in this study. Different types of OSNF membranes were prepared where commercially available PTFE ultrafiltration membrane as well as laboratory-made polysulfone ultrafiltration membranes served as the base supports, and poly (dimethylsiloxane) as the thin active layer. A thin film composite membrane was also prepared using a base support made of a mixture of polysulfone and multi-walled carbon nanotubes and a thin active layer top constituted from interfacial polymerization between m-phenylenediamine and trymesoyl chloride. For membrane characterization, Scanning Electron Microscopy (SEM) and Atomic Force Microscoopy (AFM) were performed. The performance of the membranes was studied by monitoring permeability along with the removal capacity using a dead-end filtration system, under a pressure range of 5~30 bars. A commercially available polyimide membrane, DuraMem, was exploited to compare the membrane performance. The 2.5% PTFE/PDMS (RTV 615) membrane showed the highest performance by removing 95~97% 17α- ethinylestradiol, 70% ibuprofen, 65% naproxen and 65% diclofenac. Hansen’s Solubility Parameter theory was adopted to explain the removal mechanism of pharmaceutical compounds, while size exclusion theory explained the removal of the synthetic estrogen by OSNF.


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