Gwen Williams

M.Sc. Thesis

Evaluating the Effects of Wastewater Treatment on Marine Sediment Chemistry in Halifax Harbour, Nova Scotia

(PDF - 33.1 Mb)

This study presents results on the spatial and temporal variability of metals and organic contaminants in sediments in Halifax Harbour, Nova Scotia. Decreases in sediment contaminant concentrations due to the initiation of advanced primary wastewater treatment (2009-2010) were not observed. Results from this work provide pre-industrial background and present-day contaminant concentrations as they were at the commencement of wastewater treatment in 2009-2010, which are essential for measuring success of the Harbour Solutions Project and future wastewater treatment efforts. Results indicate that future upgrading to secondary treatment levels will likely affect concentrations of dissolved contaminants to a greater extent than particle-bound contaminants. Concentrations of polycyclic aromatic hydrocarbons (PAHs), lead, zinc, and copper have not changed substantially in the last 20 years. Decreases in mercury concentrations are likely the result of increased source control. Increases in concentrations of alkylated PAHs relative to parental PAHs suggest increased input from petrogenic

Keywords:
Pages: 309
Supervisors: David Scott / Michael Parsons