Coated nickel foam electrode for the implementation of continuous electro‐Fenton treatment

BACKGROUND: Electro‐Fenton technology has already demonstrated its ability to degrade organic pollutants. In this treatment hydroxyl radicals are formed due to the reaction of the iron catalyst along with in situ electrogenerated H₂O₂. However, one of the main limitations of this system is the iron released in the treated effluent. Therefore, retention of iron is required, and in this study, the use of a new cathode in which the iron is fixed on nickel foam is proposed as a solution to the electro‐Fenton treatment in continuous processes. RESULTS: The retention of iron was ensured by its fixation on nickel foam using chitosan, an eco‐friendly polymer, as coating agent. Different chitosan coatings were tested to optimize the manufacturing process of the new cathode. It was concluded that the best electrode for the electro‐Fenton treatment of different dyes (Poly R‐478 and Lissamine Green B) was obtained using a half‐coating electrode cover with iron–chitosan of medium molecular weight. Furthermore, its reusability was positively evaluated in successive cycles. Finally, a continuous treatment using a fluidized bed reactor was successfully performed for the treatment of dye Lissamine Green B. CONCLUSION: Summarizing, this new cathode is a suitable alternative for the treatment of coloured wastewater by continuous electro‐Fenton treatment. © 2014 Society of Chemical Industry