Efficient removal of Orange G using Prussian Blue nanoparticlessupported over alumina

Abstract

Prussian Blue nanoparticles (PBNP) synthetized and adsorbed onto g-Al2O3 spheres were prepared and characterized by transition and scanning electron microscopy (TEM, SEM), energy dispersive X-ray spectroscopy (EDS) and sorptometry. Adsorption and reaction runs were performed using aqueous solutions of a model azo dye Orange G. The adsorption capacity of the PBNP/g-Al2O3 at 323 and 343 K at initial pH 3 and 6 was studied. The presence of PBNP increased the adsorption capacity of the support and this effect was more pronounced at initial pH=6. However, since the adsorbent life time was narrow and its regeneration quite difficult, PBNP/g-Al2O3was tested as a heterogeneous Fenton-like catalyst. The catalytic activity and stability for oxidation of Orange G were investigated in terms of discolouration, TOC and oxidant conversion. At the best operating condition studied (343 K and pH0= 3), complete dye discolouration and 60% of mineralization were attained while reaction largely overcomes adsorption. At this temperature the catalyst activity and its characteristics remained almost invariable during 9 cycles of 5 h each and iron leaching occurred in low extent.