Effect of Electrochemical Oxidation Processes on Acetaminophen Degradation in Various Electro-Fenton Reactors

Abstract

This study investigates the effect of pH, Fe2+ and H2O2 concentrations, and the molar ratio of H2O2 to Fe2+ on acetaminophen (ACT) degradation by the double-cathode cylinder-type and box-type electro-Fenton (EF) reactors. The effect of sulfate, nitrate, and phosphate on ACT degradation is examined. The experimental results showed that ACT removal in the box-type EF reactor was significantly more affected by Fe2+ and H2O2 concentrations than in the cylinder-type EF reactor. The optimum pH in the two reactors was 3 under low and high concentrations of Fenton's reagent. ACT removal in the two reactors decreased when the molar ratio of H2O2 to Fe2+ increased from 150 to 1500. The cylinder-type EF process had better ACT removal efficiency than the box-type EF process. A 22% increase in chemical oxygen demand (COD) removal was observed with the EF process, while a 34% increase was obtained with the photoelectro-Fenton (PEF) process. The inhibition effect of inorganic ions on ACT degradation in the EF and PEF processes was in the order of PO43−> NO3− = SO42−.