Chemical Exploration of Global Shipping: Characterization of Organic Pollutants and Disinfection Byproducts Associated with Ship Ballast Water

Commercial shipping activities place significant strain on one of our most important natural resources as demand for affordable global trade demands ever increasing marine traffic. It has long been recognized as one of the greatest threats to the health of the world’s oceans due to the translocation of invasive species by way of ballasting operations. However, the industry’s role in the global movement of anthropogenic compounds has not been previously investigated. Upcoming regulatory change will further add to the environmental burden as ships will be required to treat ballast water using disinfecting techniques, potentially generating toxic disinfection byproducts. This dissertation was thus focused on revealing current and future potential environmental impacts on the marine environment by using a combination of high resolution mass spectrometry instruments.

Ship ballast water and port water samples were analyzed using both targeted and non-targeted analyses to characterize the organic pollutant burden contained within tanks. This revealed the presence of contaminants derived from both land sources, such as agricultural runoff, as well as compounds associated with shipboard maintenance protocols. Several of these compounds are likely to serve as precursors for disinfection byproduct formation as the shipping industry begins to incorporate ballast water treatment systems. The role of natural organic matter in disinfection byproduct formation was then investigated by chlorinating natural and synthetic seawater. Using a combination of high resolution gas and liquid chromatography paired with accurate mass spectrometry, comprehensive disinfection byproduct profiles were generated to better understand environmental conditions responsible for their formation. A large amount of novel brominated compounds were tentatively identified and should be addressed further prior to global release during ballasting operations. Finally, the ability for continued disinfection byproduct formation to occur beyond quenching disinfection reactions was investigated. This is important to understand further potential risk to sensitive coastal ecosystems beyond the release of treated ballast water.

This dissertation used non-targeted workflows to supplement standard targeted analyses in order to discover compounds that may be of environmental concern relating to the shipping industry. As such, informed recommendations can be made as to the proper environmental conditions in which seawater chlorination should and should not be used. In addition, this allowed for discovery of additional novel disinfection byproducts which can be further investigated for toxicity potential.