Photo-assisted fenton mineralization of an azo-dye acid black 1 using a modified laponite clay-based Fe nanocomposite as a heterogeneous catalyst

Photo-assisted Fenton mineralization of an azo-dye Acid Black 1 (AB1) was studied in detail using a modified laponite clay-based Fe nanocomposite (Fe-Lap-RD) as a heterogeneous catalyst in the presence of H2O2 and UV light. The Fe-Lap-RD was characterized by X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), X-ray photoelectron spectroscopy (XPS), and N-2 adsorption. The effects of reaction parameters such as initial AB1 concentration, H2O2 concentration, Fe-Lap-RD catalyst loading, initial solution pH, UV light wavelength and power, and reaction temperature on the mineralization of AB1 were investigated. Under the optimal reaction conditions (6.4 mM H2O2, 1.0 g Fe-Lap-RD/L, 8 W UVC, initial solution pH = 3.0), complete discoloration and over 90% total organic carbon (TOC) removal of 0.1 mM AB1 were achieved after 90 min reaction. Discoloration kinetics of AB1 was also studied to obtain apparent reaction rate constants and reaction activation energy.