title: Effect of phosphate on the adsorption of Cu and Cd on natural hematite.
abstract: Interactions between anions and cations are important to understand the chemical processes of pollutants in environment. In this study, batch experiments were carried out to investigate the simultaneous adsorption of Cu and Cd on hematite as affected by phosphate. Phosphate pretreatment suppressed the maximum adsorption of Cu and Cd on hematite and moved the adsorption pH edges to a higher pH range. Phosphate application time had a marked impact on Cu and Cd adsorption and longer contact time resulted in more reduction of Cu and Cd adsorption. Results of back-titration, Fourier transform infrared (FTIR) spectroscopy study and ionic strength effect on the adsorption revealed that Cu and Cd were adsorbed on hematite mainly through the inner-sphere complex formation mechanism and phosphate treatment reduced the inner-sphere adsorption sites, thus decreasing Cu and Cd adsorption on hematite.
authors.affiliation: Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Shuzhen
authors.initials: S
authors.lastname: Zhang
authors.forename: Wei
authors.initials: W
authors.lastname: Jiang
authors.forename: Xiao-Quan
authors.initials: XQ
authors.lastname: Shan
mesh_terms: D000327:Adsorption; D002104:Cadmium / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry*; D012989:Soil Pollutants
chemical_list: D005290:Ferric Compounds; D010710:Phosphates; D012989:Soil Pollutants; D002104:Cadmium; C000499:ferric oxide; D003300:Copper