Time-Integrative Passive Sampler Designed for Per- and Polyfluoroalkyl Substances in Water

Presented on April 27, 2022, by Paul Edmiston - The College of Wooster - at the 2022 Emerging Contaminants in the Environment Conference (ECEC22)

Per- and polyfluoroalkyl substances (PFAS) are a class of persistent contaminants which are increasingly monitored in the hydrosphere. Passive sampling is emerging as an alternative to grab sampling for environmental monitoring due to advantages of reducing cost and providing a time-averaged measurement. The passive sampler design uses granular an adsorbent optimized for PFAS immobilized behind open mesh windows allowing direct contact with the aqueous phase. The adsorbent resin consists of a mesoporous hydrophobic organosilica modified with polyethylenimine (PEI) and Cu(II) ions to add cationic adsorption sites. Passive samplers were characterized in bench scale measurements varying flow rate, water chemistry, and PFAS concentrations. The results demonstrated an integrative response where sampling rates were relatively unaffected by changing in salinity, ORP, pH, temperature, and the presence of humic acid. Field trials measure PFAS concentrations in surface water and groundwater were conducted at Ellsworth and Peterson AFBs. Field measurements confirmed the integrative response of the samplers and showed good correlation with PFAS concentrations measured by grab sampling. Deployment strategies of the passive samplers in groundwater, surface water, and stormwater contexts will be presented.