Concentration of FeSO₄ spent solutions by membrane distillation

The possibility of potential application of membrane distillation for the concentration of waste salt solutions has been presented in this work. It was found that the oxidation of iron compounds takes place during the process that was associated with the formation of a layer of oxides on the membrane surface. A fast decline of the permeate flux was observed due to the scaling phenomena. The problem of scaling was eliminated by the acidification with H₂SO₄ of the feed to the pH value of 2.