Nanoscale zero-valent iron is a promising reagent in environmental remediation due to its high surface activity. Relative to granular zero-valent iron, it shows increased reactivity due to its higher surface area.Compared to conventional iron catalysts (supported or unsupported iron ions and/or iron oxides) [12–16], the application of active nano-Fe0 surface gives rise to Fe2+ generation and potent Fenton type reactions, and results in a modified Fenton process, Advanced Fenton Process (AFP). It is well acknowledged that the reduction of Fe3+ ion to Fe2+ is faster at the Fe0 surface compared to the homogeneous
Fenton process (only Eq. (2)), as shown in Eqs. (2) and (3).