ABSTRACT
The Al–Fe pillared interlayered clay catalyst (PILC) was synthesized by pillaring bentonite clay with Al and Fe metal cations. 4-Nitrophenol (4-NP) was oxidized over Al–Fe PILC using catalytic wet peroxide oxidation process. The catalyst was characterized using X-ray diffraction, BET, wavelength-dispersive X-ray fluorescence, FTIR, and thermogravimetric analysis/derivative thermogravimetric techniques. The Al–Fe PILC was thermally stable as compared to bentonite clay. Reaction kinetics for the catalytic oxidation of 4-NP onto Al–Fe PILC was described using Fermi’s equation. Fermi’s model was fitted well to the experimental data for the degradation of 4-NP and total organic carbon (TOC) removal histories and followed pseudo-first-order rate equation. The apparent activation energies for 4-NP degradation and TOC removal histories were 21.17 and 14.12 kJ/mol, respectively. In the present study, the mechanistic pathways for the catalytic oxidation of 4-NP based upon TOC reduction have been proposed. The toxicity of 4-NP after oxidation decreased as the zone of inhibition decreased to 5 mm from 12 mm.