Quantitative Insights into Phosphate-Enhanced Lead Immobilization on Goethite.

ABSTRACT: Despite extensive study, geochemical modeling often fails to accurately predict lead (Pb) immobilization in environmental samples. This study employs the Charge Distribution MUlti-SIte Complexation (CD-MUSIC) model, X-ray absorption fine structure (XAFS), and density functional theory (DFT) to investigate mechanisms of phosphate (PO₄) induced Pb immobilization on metal (hydr)oxides. The results reveal that PO₄ mainly enhances bidentate-adsorbed Pb on goethite via electrostatic synergy at low PO₄ concentrations. At relatively low pH (below 5.5) and elevated PO₄ concentrations, the formation of the monodentate-O-sharing Pb-PO₄ ternary structure on goethite becomes important. Precipitation of hydropyromorphite (Pb₅(PO₄

SUBMITTER: Lian W 

PROVIDER: S-EPMC11223472 | biostudies-literature | 2024 Jul

REPOSITORIES: biostudies-literature