Table : Initial and residual concentrations of metals Besides complete removal of Fe 2+ , these results showed that our targeted metals especially Mn and Zn also can be reduced or completely removed by this emerging oxidizing and coagulating agent from the synthetic AMD as the resulting pH was greater than 9. The results also confirmed the complete removal of Fe 2+ through oxidation process from synthetic AMD as shown with the UV-Vis spectroscopic results. In this regard, ferrate (VI) confirmed to be a promising oxidant, flocculent and coagulant and no harmful by-products are formed in its selfdecomposition to Fe (III) hydroxides and oxides.