主讲人简介：Dr. Liu focuses her work on environmental fate, behaviors, and bioavailability of emergingorganic contaminants, particularly polyfluoroalkyl and perfluoroalkylsubstances (PFAS). She is also developing novel materials and treatmentprocesses to remove PFASs from contaminated water and soil. Her researchprovides industry, policy- and decision-makers with information to make sounddecisions on themanufacture, assessment, andmanagement of organic chemicals.

内容摘要：Inthe aftermath of the 2013 Lac-Mégantic(Quebec,Canada)derailmentaccident, the emergency response entailed the deployment of aqueous filmforming foams (AFFFs) that contained proprietary fluorosurfactants. The presentstudy examines the environmental occurrence of over 100 legacy andnewly-identified polyfluoroalkyl andperfluoroalkyl substances (PFASs) in the benthic fish white sucker (Catostomuscommersonii), sediments from LakeMégantic and Chaudière River, and soilsfrom the site of accident and biopiles.Overall, the levels of PFAS in sedimentsand fish remained low, only slightly higher than those before the accident.Soil samples showed a much greater numberof PFAS compounds and also at levels significantly greater than non-impacted soilbut remain lower than Canada provisionalvalues.

We attributed a fewfactors to the overall low PFAS levels found in the region despite the largevolume of AFFFs released. The cleanup effort implementedto remove petroleum hydrocarbons from wastewater appeared to have removed a significantportionof AFFFs and PFASs from the waste stream. The AFFFs used during the accident belong to the new generation of firefightingagents, free of perfluorooctane sulfonate (PFOS) perfluorooctanoic acid (PFOA),and are less bioaccumulative than the older formulations. Aside from verifyingthe effectiveness of PFOS ban in Quebec, the knowledge generated from the studyprovides insight into the fate and behaviors or PFAS in engineered water andsoil treatment processes that are designed to remove petroleum hydrocarboncontaminants.