The application of the advanced oxidation process using a green oxidant Na2FeO4 for the treatment of a synthetic AMD sample was performed. The results indicated that this method could be effective for ameliorating the quality of sludge generated through the oxidation process of iron (II) and removal of other metals from the AMD. Metals were removed through coagulation and co-precipitation processes due to ferric ions generated from the oxidation of iron (II) and breakdown of ferrate (VI) ions. The produced sludge was characterized by, SEM-EDS, XRD and FT-IR while the concentration of metals was determined using ICP-OES and UV-Vis spectroscopy analyses. The UV-Vis analysis results confirmed with the ones of ICP-OES that iron has completely removed from the synthetic AMD, which also confirmed the prevented the sludge from bulking. Only 15 minutes are enough for all metals to be removed from the water when it is being treated with this novel sodium ferrate (VI).