title: A comparative study on sorption of perfluorooctane sulfonate (PFOS) by chars, ash and carbon nanotubes.
abstract: Perfluorooctane sulfonate (PFOS), as one of emerging contaminants, has been attracting increasing concerns in recent years. Sorption of PFOS by maize straw- and willow-derived chars (M400 and W400), maize straw-origin ash (MA) as well as three carbon nanotubes (CNTs) was studied in this work. The sorption kinetics of PFOS by the six adsorbents was well fitted by the pseudo-second-order model. CNTs reached equilibrium in 2h, much faster than those by chars (384 h) and ash (48 h). According to the sorption isotherms, both single-walled carbon nanotubes (SWCNT) and MA had high sorption capacities (over 700 mg g(-1)), while the two chars had low sorption capacities (below 170 mg g(-1)) caused by their small BET surface area. In the case of MA, due to its positively charged surface, both hydrophobic interaction and electrostatic attraction involved in the sorption, and the formation of hemi-micelles further favored the sorption. This study suggested that SWCNT and MA were effective adsorbents for PFOS removal from water. Compared to SWCNT, MA is low cost and easy to obtain, so it could be a preferred adsorbent for PFOS removal.
authors.affiliation: School of Environment, Beijing Normal University, State Key Laboratory of Water Environment Simulation, Beijing 100875, China.
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
authors.forename: Xinghui
authors.initials: X
authors.lastname: Xia
authors.forename: Xilong
authors.initials: X
authors.lastname: Wang
authors.forename: Jinping
authors.initials: J
authors.lastname: Qiao
authors.forename: Huiting
authors.initials: H
authors.lastname: Chen
mesh_terms: D000327:Adsorption; D017738:Alkanesulfonic Acids / Q000032:analysis / Q000737:chemistry*; D002606:Charcoal / Q000737:chemistry*; D005466:Fluorocarbons / Q000032:analysis / Q000737:chemistry*; D007700:Kinetics; D037742:Nanotubes, Carbon / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
chemical_list: D017738:Alkanesulfonic Acids; D005466:Fluorocarbons; D037742:Nanotubes, Carbon; D014874:Water Pollutants, Chemical; C540010:biochar; D002606:Charcoal; C076994:perfluorooctane sulfonic acid