The redistribution process of As(Ⅲ) and Fe(Ⅱ) caused by As/Fe ratio, organic matter, and co-existing ions: Co-precipitation and co-oxidation

The contamination of arsenic (As) in aqueous environments has drawn widespread attention, and iron compounds may largely alter the migration ability of As. However, the stability of As(III) in Fe-As system with the intervention of organic matter (OM) remains unclear. Herein, we had explored the co-precipitation and co-oxidation processes of As-Fe system by using batch experiments combined with Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS) in this research. The precipitation quantity of As(III) increased (28.85-92.41 %) when the As/Fe ratio decreased, and increased (24.20-64.20 %) with pH increased. The main active substance for oxidizing As(III) was H