Affiliation:
1. Yale University
2. Gwangju Institute of Science and Technology
3. Brown University
4. Rice University
5. Auburn University
Abstract
Abstract
Here, we describe surface functionalized, superparamagnetic iron oxide nanocrystals (IONCs) for ultrahigh PFAS sorption and precise, low energy (magnetic) separation, considering perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). As a function of surface coating, sorption capacities described are considerably higher than previous studies using activated carbon, polymers, and unmodified metal/metal oxides, among others. In particular, positively charged polyethyleneimine (PEI) coated IONCs demonstrate extreme sorption capacities for both PFOA and PFOS due to electrostatic and hydrophobic interactions, along with high polymer grafting densities, while remaining stable in water, thus maintaining available surface area. Further, through a novel method using a quart crystal microbalance with dissipation (QCM-D), we present real-time, interfacial observations (e.g. sorption kinetics). Through this method, we explore underpinning mechanism(s) for differential PFAS (PFOA vs PFOS) sorption behavior(s), demonstrating that PFAS functional head group strongly influence molecular orientation on/at the sorbent interface. The effect of water chemistry, including pH, ionic composition of water, and natural organic matter on sorption behavior are also evaluated and along with material (treatment) demonstration via bench-scale column studies.
Publisher
Research Square Platform LLC
Reference80 articles.
1. Isomer-specific binding affinity of perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) to serum proteins;Beesoon S;Environmental science & technology,2015
2. Perfluoroalkyl substances (PFAS) in surface water and sediments from two urban watersheds in Nevada, USA;Bai X;Science of The Total Environment,2021
3. Guideline levels for PFOA and PFOS in drinking water: the role of scientific uncertainty, risk assessment decisions, and social factors;Cordner A;Journal of Exposure Science & Environmental Epidemiology,2019
4. Detection of poly-and perfluoroalkyl substances (PFASs) in US drinking water linked to industrial sites, military fire training areas, and wastewater treatment plants;Hu XC;Environmental science & technology letters,2016
5. PFAS concentrations in soils: Background levels versus contaminated sites;Brusseau ML;Science of The Total Environment,2020