title: Effect of salinity and sediment characteristics on the sorption and desorption of perfluorooctane sulfonate at sediment-water interface.
abstract: This study investigated the influence of solution salinity, pH and the sediment characteristics on the sorption and desorption of perfluorooctane sulfonate (PFOS). The results showed that the sorption of PFOS onto sediment increased by a factor of 3 as the CaCl(2) concentration increased from 0.005 to 0.5 mol L(-1) at pH 7.0, and nearly 6 at pH 8.0. Desorption hysteresis occurred over all salinity. The thermodynamic index of irreversibility (TII) values increased with increasing concentration of CaCl(2). Maximum irreversibility was found in the sorption systems with CaCl(2) in the concentration of 0.5 mol L(-1). The results suggested that PFOS can be largely removed from the water with increasing salinity, and get trapped onto sediments irreversibly. These phenomena could be explained by salting-out effect and Ca-bridging effect. Studies also suggested that the content of total organic carbon is the dominant psychochemical properties of sediment controlling the sorption of PFOS.
authors.affiliation: State Key Lab of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085, China.
authors.forename: Chun
authors.initials: C
authors.lastname: You
authors.forename: Chengxia
authors.initials: C
authors.lastname: Jia
authors.forename: Gang
authors.initials: G
authors.lastname: Pan
mesh_terms: D000327:Adsorption; D017738:Alkanesulfonic Acids / Q000737:chemistry*; D052918:Environmental Restoration and Remediation / Q000295:instrumentation / Q000379:methods*; D005466:Fluorocarbons / Q000737:chemistry*; D019015:Geologic Sediments / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D017738:Alkanesulfonic Acids; D005466:Fluorocarbons; D014874:Water Pollutants, Chemical; C076994:perfluorooctane sulfonic acid