Preparation Of 2-Ethylanthraquinone Modified Gas Diffusion Electrode And Application On Phenol Degradation In Wastewater With Electro-Fenton Mathod

In this paper a 2-ethylanthraquinone (2-EAQ) modified gas diffusion electrode was introduced into electro-Fenton system to oxidate phenol in wastewater. As a cathode,2-EAQ modified gas diffusion electrode generated hydrogen peroxide for Fenton reaction by 2-EAQ autoxidation property and oxygen reduction reaction. Fe2+ for Fenton reaction was added at the beginning and may provided durativily by anode sacrificed. Under the synergy of electro-Fenton system, a hydroxyl radical (·OH), as a nonselected oxidation agent, would degrade phenol in wastewater.At first, the basic structure, component and physical, chemical properties of organic catalyst 2-EAQ were obtained by XRD, FITR, GC, TG-DTA. 2-EAQ autoxidation property was approved by CV test, and also that 2-EAQ autoxidation could exsit in 1-14 range of pH. A simple 2-EAQ modified glassy carbon electrode was prepared for study the oxygen reduction reaction on carbon materials in acid and alkali. The different mechanism of 2-EAQ reduction was investigated that a 2 proton 2 electron reaction happened in acid but 2 proton 1 electron reaction happened in alkali.Considering the preparation and resistant in acid and alkali, two supporter, nickel web and carbon clothes, were used. The physical and chemical properties of 2-EAQ modified gas diffusion electrodes were obtained by XRD, SEM, hydrophobic angle test, Four Probes test and BET. The reductive peaks of oxygen reduction reaction and the pair of peaks related to 2-EAQ autoxidation were shown on CV curves in alkali but acid because of the different reaction mechanism.Concentration of hydroxyl radicals was determined by automatic potentiometric titration. Two electrochemical cell for phenol degradation was designed. Electrolytes contained 100 mg·L-1 phenol,10 g·L-1 FeSO4,10 g·L-1 Na2SO4, pH=3, electrodes distance 2 cm, current density 600 A·m-2, area of electrodes 20 cm2, electrolysis time 60min. The degradation rates of phenol were increased in dependence of electrolysis time. When the proportion of 2-EAQ in gas diffusion electrode was more than 20%, the degradation rates of phenol was constant,80% with Fe anode after 60min.