title: Effects of pH and anions on the sorption of selenium ions onto magnetite.
abstract: This study analyzes the influence of carbonate and silicate, which are generally abundant in granitic groundwater, on the sorption of selenium ions onto magnetite in order to understand the behaviors of selenium in a radioactive waste repository. Selenite was sorbed onto magnetite very well below pH 10, but silicate and carbonate hindered the sorption of selenite onto magnetite. On the other hand, little selenate was sorbed onto magnetite in neutral and weak alkaline solutions of 0.02 M NaNO(3) or NaClO(4), matching the ionic strength in a granitic groundwater, even though silicate or carbonate was not contained in the solutions. The surface complexation constants between selenite and magnetite were obtained by using a geochemical program, FITEQL 4.0, from the experimental data, and the formation of an inner-sphere surface complex such as =FeOSeO(2)(-) was suggested for the sorption of selenite onto magnetite from the diffuse double layer model calculation.
authors: Radioactive Waste Technology Development, Korea Atomic Energy Research Institute, 1045 Daedeok-Daero, Yuseong-gu, Daejeon 305-353, Republic of Korea. nsskim@kaeri.re.kr
authors: Seung Soo
authors: SS
authors: Kim
authors: Je Ho
authors: JH
authors: Min
authors: Jae Kwang
authors: JK
authors: Lee
authors: Min Hoon
authors: MH
authors: Baik
authors: Jong-Won
authors: JW
authors: Choi
authors: Hyung Seon
authors: HS
authors: Shin
mesh_terms: D000327:Adsorption; D000838:Anions / Q000032:analysis / Q000737:chemistry*; D004785:Environmental Pollutants / Q000737:chemistry* / Q000302:isolation & purification; D052203:Ferrosoferric Oxide / Q000737:chemistry*; D060587:Groundwater / Q000032:analysis / Q000737:chemistry / Q000592:standards; D006863:Hydrogen-Ion Concentration; D058085:Iron Compounds / Q000737:chemistry; D008962:Models, Theoretical; D011850:Radioactive Waste / Q000517:prevention & control; D012643:Selenium / Q000737:chemistry* / Q000302:isolation & purification; D018036:Selenium Compounds / Q000737:chemistry; D013499:Surface Properties; D018505:Waste Management / Q000379:methods*
chemical_list: D000838:Anions; D004785:Environmental Pollutants; D058085:Iron Compounds; D011850:Radioactive Waste; D018036:Selenium Compounds; D012643:Selenium; D052203:Ferrosoferric Oxide