Arsenic Adsorption and its Fractions on Aquifer Sediment: Effect of pH, Arsenic Species, and Iron/Manganese Minerals

摘要: Effects of pH, As species, and Fe/Mn minerals on the fractions adsorbed in aquifer sediments were evaluated. Kinetic data showed that adsorption was controlled by diffusion through external film. Isothermal both As(III) As(V) fitted Langmuir isotherm well, revealing a monolayer process. Sequential extraction demonstrated water-soluble non-specifically sorbed major As. Assessing relationship between Freundlich K F increases amounts pH played key role weakly As, especially Although inorganic species converted each other during processes, more As(V)-treated sediment than As(III)-treated sediment, showing electrostatic selectivity non-specific adsorption. Additionally, specifically associated with amorphous phases predominated minerals, Fe(III) (hydr)oxides. These results suggested would regulate sediments, therefore control cycling systems.