Iron(III)-induced photooxidation of arsenite in the presence of carboxylic acids and phenols as model compounds of natural organic matter

Iron species have essential influence on the environmental/geochemical behaviors of arsenic in water and soil. Colloidal ferric hydroxide (CFH) induces photooxidation arsenite (As(III)) to arsenate (As(V)) at neutral pH through surface complexation ligand-to-metal charge transfer (LMCT). However, effect co-existing natural organic matter (NOM) complexation-photolysis this process has remained unclear. In present work, As(III) induced by CFH was investigated presence various carboxylic acids polyphenols as simple model compounds NOM. Two different light sources ultraviolet A (UVA) (?max = 365 nm) B (UVB) 313 were used for treatment experimental ternary system control binary respectively. The obtained results demonstrated that all NOM inhibited As(III)/CFH 7. Moreover, correlation analysis between pseudo-first order rate constant kobs property parameters showed stable Fe(III) (logKFe-NOM) well molecular weight percentages total acidity exhibited significant correlations. quantitative structure-activity relationship (QSAR) established these three utilizing a multiple linear regression method, which can be employed estimate efficiency iron Thus, work contributes understanding environmental interactions iron.