Iron recovery from the Fenton's treatment of winery effluent using an ion-exchange resin

A new sludge free Fenton's process for wastewater treatment is proposed. Fenton's reagent is an interesting oxidation treatment for organic matter removal from liquid effluents. However, its main drawback is the iron sludge produced at the end of the reaction. An integrated methodology is recommended involving the application of ion exchange resins that recover dissolved iron without the need of sludge production. The results reveal high iron removal efficiencies (~ 100%). On the other hand, this strategy is able to fulfill iron removal requirements even if some iron precipitation occurs during Fenton's peroxidation. In fact, sludge dissolution is promoted and the resulting dissolved iron is then adsorbed by the resin. Langmuir model was able to satisfactorily describe the experimental results leading to a qm = 56 mg/g. A design of experiments approach allowed concluding that pH is a key parameter for ion-exchange. This combined strategy overcomes Fenton's main shortcoming and will boost the industrial application of this interesting wastewater treatment approach.