Arsenate and Chromate Retention Mechanisms on Goethite. 1. Surface Structure
Citations Over TimeTop 1% of 1997 papers
Abstract
The molecular structure of ions retained on mineral surfaces is needed to accurately model their sorption process and to determine their stability. Extended X-ray absorption fine structure (EXAFS) spectroscopy was used in this study to deduce the local coordination environment of two environmental contaminants, arsenate and chromate, on the mineral goethite (α-FeOOH). Based on the oxyanion−Fe distances, it was concluded that three different surface complexes exist on goethite for both oxyanions: a monodentate complex, a bidentate-binuclear complex, and a bidentate-mononuclear complex. At low surface coverages, the monodentate complex was favored while at higher coverages the bidentate complexes were more prevalentthe bidentate-binuclear complex appears to be in the greatest proportion at these highest surface coverages. Therefore, modeling efforts for chromate or arsenate retention on goethite need to consider a monodentate complex at very low coverages, both the monodentate and bidentate complexes at intermediate coverages, and predominantly the bidentate complexes at very high coverages.
Related Papers
- → Individual and competitive adsorption of phosphate and arsenate on goethite in artificial seawater(2003)141 cited
- → Competitive and cooperative adsorption of arsenate and citrate on goethite(2009)36 cited
- → Using machine learning to explore oxyanion adsorption ability of goethite with different specific surface area(2023)15 cited
- Effect of Dissolved Organic Acids on Arsenate Adsorption-desorption onto Soil Mineral(2009)
- → [Characteristics and Influencing Factors of Monothioarsenate Adsorption on Goethite].(2020)