Halo-organic pollutants: The effect of an electrical bias on their decomposition mechanism on porous iron electrodes

[Display omitted] •Electrical bias on an iron electrode dramatically changes de-halogenation products.•Alkyl radicals are formed during the de-halogenation of organic compounds by ZVI.•FeC σ bond polarity is reversed when significant negative potential is applied on iron electrode.•Negative potential inhibits the passivation of the ZVI.•In batch pollutants de-halogenations, negative potential bias should be applied. The de-halogenation processes of CH2BrCHBrCOO− and of CH2ClCH(OH)COO− on Zero Valent Iron (ZVI) powders and porous iron electrodes were studied. The results suggest that by applying a negative voltage bias on the electrode, the composition of the products obtained is dramatically changed. Furthermore, the applied potential inhibits the passivation of the ZVI. Thus, it is recommended that the application of a negative potential to porous ZVI is desirable in batch treatment of halo-organic pollutants.