A new type of continuous-flow heterogeneous electro-Fenton reactor for Tartrazine degradation

A new type of continuous-flow heterogeneous electro-Fenton (EF) reactor, in which electrochemically formed H2O2 was externally injected to the iron-carbon granules packed bed, was designed to degrade a model dye, Tartrazine. The gas diffusion electrode (GDE) can generate H2O2 efficiently, and the iron-carbon granules were used as the heterogeneous catalyst for the Fenton oxidation of the pollutants. The important operating parameters such as initial concentration of Tartrazine, pH, modified Fe-C dosage, wastewater flow rate and current were optimized. The continuous-flow EF reactor exhibited good performance even after 12 h continuous operations with the Tartrazine removal of 80% and TOC removal of nearly 30%. Compared with the conventional EF reactor, this novel continuous EF reactor can efficiently degrade the target pollutants from low concentration electrolyte. The electric energy consumption in this new type continuous-flow reactor was 0.15 kWh/(g TOC), whereas it was 0.69 kWh/(g TOC) in the batch reactor under the same experimental conditions. All results demonstrated that this novel EF system was energy-efficient and potential for treatment of wastewater without or low concentration electrolyte.