Removal of phenol by heterogenous photo electro Fenton-like process using nano-zero valent iron

This study presents the removal of phenol by heterogenous photo electro Fenton-like (PEF-like) system using nano-zero valent iron (NZVI). NZVI was characterized using X-ray diffraction (XRD) and Scanning Electron Microscope (SEM) analysis. The effect of initial pH, initial concentration of phenol, NZVI dosage and initial H2O2 concentration on phenol removal was studied. The removal efficiency was increased with an increase in NZVI dosage and decreased with an increase in initial phenol concentration and initial pH. The optimum dosage of NZVI and H2O2 were found to be 0.5 g/L and 500 mg/L, respectively and complete removal of phenol was observed within 30 min at these conditions at an initial pH and initial phenol concentration of 6.2 and 200 mg/L, respectively. The analysis of kinetics showed that the removal of phenol by PEF-like process followed pseudo first-order kinetics. The variation of H2O2 concentration during the reaction was monitored at different current densities and the optimum current density was found to be 12 mA/cm2.

► Performance of different Fenton based processes was compared.
► Possibility of the usage of NZVI in Fenton processes was explored.
► PEF-like process with NZVI was studied for the degradation of phenol in detail.