title: Arsenic distribution and adsorption behavior in the sediments of the Daliao River System in China.
abstract: This study investigated the arsenic (As) distribution and adsorption behavior in sediments of the Daliao River System (DRS). Results indicated that the total As was 2.6-83.1 mg kg(-1) in the sediments of the DRS. The pseudo-first order model and intra-particle diffusion model give a good fit of the experimental kinetics data for As, indicating that particle diffusion mechanism may not be the rate controlling step while this mechanism is involved. By comparing the zero equilibrium As concentration (EAsCo) with the actual As concentration in the overlying water of the DRS, all the sediments showed a trend of releasing As. Arsenic exhibited strong adsorption on sediment at pH 4.5-7. Arsenic retention by sediment was much enhanced by Ca2+ compared to Na+. More As was desorbed by phosphate at low and high pH extremes. The added or sorbed As was mainly transferred to the specifically sorbed fraction and amorphous Fe (Al) oxyhydroxides bound fraction, indicating Fe oxides are a major sorbent of As in sediment.
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Beijing Normal University, Beijing 100875, China.
authors.forename: Shiliang
authors.initials: S
authors.lastname: Wang
authors.forename: Chunye
authors.initials: C
authors.lastname: Lin
authors.forename: Mengchang
authors.initials: M
authors.lastname: He
authors.forename: Xitao
authors.initials: X
authors.lastname: Liu
authors.forename: Shaoqing
authors.initials: S
authors.lastname: Liu
mesh_terms: D000327:Adsorption; D000838:Anions; D001151:Arsenic / Q000032:analysis*; D019015:Geologic Sediments / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D045483:Rivers / Q000737:chemistry; D013816:Thermodynamics
chemical_list: D000838:Anions; D001151:Arsenic