Heterogeneous Fenton Oxidation Process Using Natural Martite

The current study aims to investigate removal of a triarylmethane dye called Acid Blue 5 (AB5) via heterogeneous Fenton-like process and compare it with its homogeneous counterpart. The heterogeneous and homogeneous catalysts used were martite and FeCl3.6H2O, respectively. The unmilled martite microparticles were processed with high energy planetary ball mill to form nanosized catalyst for heterogeneous Fenton-like process. Characterization was performed by SEM, EDX, X-ray dot mapping, BET, XRD, FT-IR, petrography and point of zero charge analyses. Among the three batches of martite nanoparticles formed with milling time of 1 h, 3 h and 5 h at the milling speed of 300 rpm, the catalytic performance of 5h milled nano-sized martite (19.23 m2/g of surface area) was the highest. The influence of initial pH, catalyst dosage, H2O2, initial dye concentration and scavengers on the AB5 degradation was investigated comparatively for heterogeneous and homogeneous processes. AB5 removal efficiency in heterogeneous system was either higher or the same as the homogeneous system in each case.