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

Pillared laponite clay-based Fe nanocomposites as heterogeneous catalysts for photo-Fenton degradation of acid black 1

A series of pillared laponite clay-based Fe nanocomposites (denoted as Fe-Lap-RD) were synthesized by the so-called pillaring technique under different conditions. N-2 adsorption/desorption, X-ray fluorescence spectroscopy (XRF), X-ray photoelectron spectroscopy (XPS), and X-ray powder diffraction (XRD) were used to characterize the Fe-Lap-RD nanocomposites. The photo-catalytic activity of the Fe-LapRD nanocomposites was evaluated in the photo-Fenton mineralization of 0.1 mM azo-dye acid black 1 (AB1) in the presence of 6.4 mM H2O2, 8W UVC light at an initial solution pH of 3.0. It was found that 100\% mineralization of the model pollutant AB1 was achieved, while only trace amount of leached ferric ion was detected after 120 min reaction when 1.0 g/l Fe-Lap-RD was used as catalyst, which was prepared without thermal aging, followed by calcination at 723 K. Due to its high photo-catalytic activity and negligible Fe leaching, the Fe-Lap-RD nanocomposite is a promising heterogeneous catalyst for the photo-Fenton mineralization of organic compounds. (C) 2004 Elsevier Ltd. All rights reserved