Solar-light-assisted Fenton oxidation of 2,4-dinitrophenol (DNP) using Al2O3-supported Fe(III)-5-sulfosalicylic acid (ssal) complex as catalyst

Photoassisted Fenton oxidation of 2,4-dinitrophenol (DNP) was studied in detail using a novel Fe(III)-5-sulfosalicylic acid (ssal) complex loaded Al2O3 as catalyst in the presence of H2O2 and solar light. The effects of different reaction parameters such as initial pH, catalyst loading, H2O2 dosage, initial substrate concentration and temperature on photodegradation were investigated and the optimal operational parameters are reported. The repeatability of photocatalytic activity was also tested. The oxidative degradation of DNP by photo-Fenton-type process in the initiation phase and the fast phase both followed the pseudo-first-order kinetics, and possible reaction mechanisms describing the role of the ligand 5-sulfosalicylic acid and the route of degradation were proposed. The Al2O3-supported [Fe(III)-ssal] complex catalyst was found to be very efficient in the decolorization and COD reduction of real wastewater from DNP manufacturing. Thus, this study showed the feasible and potential uses of the catalytic system in oxidative degradation of various organic contaminants and industrial effluents.