Growing urban populations and climate change are placing increased pressure on our water resources, leading communities to use nontraditional water supplies, such as water reuse, stormwater capture, and desalination. To enable safe adoption of these water resources, and to protect the environment from hazardous chemicals, we need technologies that can efficiently address a wide array of contaminants. Our research develops efficient treatment systems, investigates the formation of toxic transformation products from trace organic contaminants, and assesses opportunities for safer alternatives to replace toxic chemicals used in consumer products.
Our research methods include using sensitive analytical techniques, developing experimental methods to investigate chemical transformations, and partnering on pilot-scale projects to advance efficient and sustainable engineering technologies.
Designing natural treatment systems that can efficiently treat multiple contaminant classes.
Transformations of Emerging Contaminants
Addressing trace contaminants and their transformation products in water systems.
Assessing safer alternatives to toxic trace contaminants.
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.