title: Adsorption of perfluoroalkyl acids by carbonaceous adsorbents: Effect of carbon surface chemistry.
abstract: Adsorption by carbonaceous sorbents is among the most feasible processes to remove perfluorooctane sulfonic (PFOS) and carboxylic acids (PFOA) from drinking and ground waters. However, carbon surface chemistry, which has long been recognized essential for dictating performance of such sorbents, has never been considered for PFOS and PFOA adsorption. Thus, the role of surface chemistry was systematically investigated using sorbents with a wide range in precursor material, pore structure, and surface chemistry. Sorbent surface chemistry overwhelmed physical properties in controlling the extent of uptake. The adsorption affinity was positively correlated carbon surface basicity, suggesting that high acid neutralizing or anion exchange capacity was critical for substantial uptake of PFOS and PFOA. Carbon polarity or hydrophobicity had insignificant impact on the extent of adsorption. Synthetic polymer-based Ambersorb and activated carbon fibers were more effective than activated carbon made of natural materials in removing PFOS and PFOA from aqueous solutions.
authors.affiliation: Department of Civil Engineering, McGill University, Montreal, Quebec, H3A 0C3, Canada.
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhi
authors.affiliation: Department of Civil Engineering, McGill University, Montreal, Quebec, H3A 0C3, Canada. Electronic address: jinxia.liu@mcgill.ca.
authors.forename: Jinxia
authors.initials: J
authors.lastname: Liu
mesh_terms: D000327:Adsorption; D017738:Alkanesulfonic Acids / Q000032:analysis* / Q000737:chemistry; D002244:Carbon / Q000737:chemistry*; D000077482:Carbon Fiber; D002264:Carboxylic Acids / Q000032:analysis / Q000737:chemistry; D002606:Charcoal / Q000737:chemistry*; D005466:Fluorocarbons / Q000032:analysis* / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D013499:Surface Properties; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
chemical_list: D017738:Alkanesulfonic Acids; D000077482:Carbon Fiber; D002264:Carboxylic Acids; D005466:Fluorocarbons; D014874:Water Pollutants, Chemical; D002606:Charcoal; C073608:perfluorooctane; D002244:Carbon
keywords: Activated carbon fibers; Basicity; Carbonaceous sorbents; PFOA; PFOS; Surface chemistry