Date of Award
Thesis - Restricted
Doctor of Philosophy (PhD)
Civil and Environmental Engineering
McNamara, Patrick J.
Zitomer, Daniel H.
Mayer, Brooke K.
Estrogenic compounds in water pose a range of ecological health risks such as fish feminization and public health risks including reproductive health issues, precocious puberty, cancer, and increased rates of obesity and diabetes. Drinking water treatment systems were not designed to remove estrogenic compounds. This research evaluated the use of advanced drinking water treatment processes, specifically electrocoagulation (EC) and electrooxidation (EO), for the removal of estrogenic compounds. Bench-scale experiments revealed that, during EC, current density correlated well with an increase in estrogenic compound removal, while conductivity did not impact removal. Higher stir rates and faster polarity reversal times improved estrogenic compound removal. Iron oxide flocs were characterized to identify the possible removal mechanisms via redox reactions and adsorption. Higher pH yielded greater removal than neutral and low pH. Turbidity and dissolved organic carbon had minimal impact on removal. Removal mechanisms were evaluated through a series of experiments to determine the roles of adsorption, indirect oxidation via oxidants generated within the bulk solution, and direct oxidation via oxidants adsorbed to the surface of the electrode and/or direct electron transfer. Indirect oxidation and adsorption contributed minimally to estrogenic compound removal while direct anodic oxidation ostensibly was the major removal mechanism. Finally, an EC-EO system was investigated for humic acid (bulk organic carbon) and estrogenic compound removal. Employing EC as a pre-treatment process to EO successfully removed bulk organic carbon and reduced downstream energy demand in EO for estrogenic compound removal. The energy required to remove estrogenic compounds through the EC-EO process was lower than EC alone, EO alone, and literature values for other technologies. This research demonstrated that EC-EO could be employed for simultaneous removal of bulk organic matter and estrogenic compounds.
Available for download on Wednesday, October 14, 2020