NaHCO3 enhanced Rhodamine B removal from aqueous solution by graphite–graphite electro Fenton system

• Graphite–graphite electro Fenton system was successfully applied for dye removal.
• NaHCO3 was found as better supporting electrolyte.
• RhB degradation pathway has been proposed.

Dyes are toxic and carcinogenic materials that exist in the aquatic environment. It is of great research interest in the field of environmental engineering to remove dyes from the aquatic environment. This study investigated the Rhodamine B (RhB) removal efficiency of graphite–graphite electro Fenton (EF) system. Batch experiments were conducted to study the effects of main parameters, such as Fe2+ concentration, initial solution pH and supporting electrolyte concentrations on dye removal. The optimum pH and Fe2+ concentration for 10 mg/l RhB solution was found to be 3 and 10 mg/l, respectively. Increase in dye removal efficiency of EF system was observed with the addition of NaHCO3 and is mainly due to the additional hydroxyl radical production. The experimental results indicated that ∼99% of RhB was removed by the reaction with OH radicals generated from the electrolytically assisted Fenton’s reaction, after 180 min of electrolysis. Degradation pathway for the RhB removal was proposed from gas chromatography mass spectrometer (GC/MS) data. From the present study, it can be concluded that graphite–graphite electro Fenton system in the presence of NaHCO3 is an efficient tool for the removal of dyes from aqueous solution.