In this investigation the degradation of a methylene blue sample was evaluated using the principle of the homogeneous Fenton Like process where iron as a catalyst was recovered from a synthetic sample of acid mine drainage by selective precipitation. Globally, acid mine drainage is considered an important residue of extractive mining and its uncontrolled dumping has negative effects on the ecosystem. Recovering a waste and using it as input to treat another is a relevant opportunity. Selective precipitation of iron was performed using a saturated solution of calcium hydroxide. The precipitated iron (III) hydroxide was solubilized with sulfuric acid to obtain iron (III) sulfate and then was used as a catalyst in the tests of degradation of methylene blue having as variables the amount of iron (III) sulfate, hydrogen peroxide, pH and time. All tests determined a degradation percentage abov...