Research

Growing urban populations, industrial and agricultural activities, and climate change are placing increased pressure on our water resources. At the same time, the ubiquitous release of chemicals from human activities poses risks to both human health and ecosystems, and exacerbates physical water scarcity. Our research aims to address the impacts of anthropogenic contaminants on communities and the environment. We focus primarily on trace organic contaminants that are toxic to aquatic organisms and humans. Our approach includes developing treatment systems that remove contaminants from water (and stormwater, wastewater), investigating the formation of toxic transformation products in treatment systems, and assessing opportunities to reduce the use of toxic chemicals.

Our research methods include using sensitive analytical techniques, developing experimental methods to investigate chemical transformations, and partnering on pilot-scale projects to advance sustainable technologies for cities and communities.

---

Current Projects

Trace contaminant fate in stormwater bioretention cells. In urban areas, stormwater runoff transports contaminants from roads and buildings to nearby aquatic ecosystems. The resulting mixture of chemical contaminants includes transformation products with poorly understood occurrence and fate that may contribute to urban runoff toxicity (e.g., the tire rubber-derived 6PPD-quinone, which is acutely toxic to coho salmon). Green infrastructure, including constructed wetlands and bioretention cells, are increasingly used to reduce flooding during storm events, but they are currently not capable of removing toxic and relatively hydrophilic trace organic contaminants. Our group is investigating the occurrence of transformation products in urban stormwater, their fate in bioretention systems, and opportunities to amend green infrastructure systems to enhance removal of trace organic contaminants.

Formation of toxic byproducts via reactive nitrogen species. Reactive nitrogen species (RNS) react with organic compounds to form nitrated and nitrosated byproducts that are often more toxic than the parent compounds. RNS formation occurs in sunlit surface waters and in water treatment systems using UV light. We are investigating the role of RNS in contaminant transformations and formation of nitrated and nitrosated byproducts. See our recent review on this topic here!

Endocrine disrupting compounds in the Strait of Georgia. Endocrine disrupting chemicals (EDCs) comprise a class of emerging contaminants that includes naturally-occurring and synthetic chemicals that interfere with hormone systems. Complex mixtures of EDCs occur in wastewater treatment plant effluent and have the potential to adversely affect aquatic ecosystems. Our group is partnering with collaborators in oceanography and environmental microbiology to assess the impacts of EDCs in the Strait of Georgia by pairing bioassays with suspect screening approaches using high resolution mass spectrometry.