Feasibility of an electrochemically assisted Fenton method using Fe^2 +/HOCl system as an advanced oxidation process

The feasibility of an electrochemically assisted Fenton treatment using a Fenton-type reaction of ferrous iron (Fe^2 +) and hypochlorous acid (HOCl) is discussed in this research. The reactor used was composed of an undivided single cell with a ruthenium dioxide-coated titanium anode and a stainless steel cathode, in which Fe^2 + and HOCl were catalytically regenerated from ferric iron at the cathode and chloride ion at the anode, respectively. Although the reactor functioned well, the degradation rate of 1,4-dioxane as a hydroxyl radical probe decreased at the current density more than 6.92 mA cm⁻². The decrease in degradation rate was inferred to be caused by the vain consumption of hydroxyl radicals by excess HOCl and the deposition of ferric hydroxide on the cathode at relatively high current density. The current efficiency of 1,4-dioxane removal remained more than 90% at the current density less than 6.92 mA cm⁻² and the iron concentration not less than 1.0 mmol L⁻¹. Consequently, this technique is thought to be applicable to the treatment of wastewater containing high concentration of chloride ion such as landfill leachate, scrubber wastewater from incineration plants, etc.