Electro-Fenton Method Oxidation of Salicylic Acid in Aqueous Solution with Graphite Electrodes

Electro-Fenton (EF) oxidation of salicylic acid (SA) from an aqueous solution was studied in a continuous stirred tank reactor with the purpose of optimizing the process parameters on a laboratory scale. A laboratory-scale continuous-flow rectangular reactor, with a predetermined 3 L liquid volume of SA in the reactor, was used for this study. Electrolytic reactions carried out for 100mg/L of SA solution, the parameters of catalyst concentration, pH, voltage, flow rate (residence time), and electrode spacing were varied. Electrolysis was carried out for a period of 10h to optimize these parameters. A maximum of 70% oxidation was obtained at an initial Fe2+ concentration of 5mg/L, pH of 2.5, voltage of 2.5 V, flow rate of 10mL/min, and electrode spacing of 3cm, after 10h of electrolysis. Results obtained show the feasibility of this continuous EF process for the oxidation of SA.