METHYL ORANGE DEGRADATION USING Fe-ZSM-11 AS PHOTOCATALYST

S. GOMEZ, C. LEAL MARCHENA, M. DOMINE, L. PIZZIO, L. PIERELLA

Congreso; XXII INTERNATIONAL MATERIALS RESEARCH CONGRESS; 2013

In the present work the use of Fe-ZSM-11 catalysts in the photocatalytic degradation of methyl orange, an azodic dye present in wastewater from the textile industry, is presented. The materials were prepared using FeSO4 as Fe precursor and NH4-ZSM-11 (a medium pore zeolite) as support. The amount of FeSO4 was varied to obtain Fe concentrations of 2 and 10% (w/w) in the final material. The catalysts were characterized by various analytical techniques: X-ray diffraction (XRD), infrared spectrometry (FT-IR), N2 adsorption-desorption isotherms at the liquid-nitrogen temperature and Inductively coupled plasma - Optical Emission Spectroscopy (ICP-OES). The results showed a high crystallinity of the materials and the absence of characteristic peaks or bands iron oxides (XRD and FT-IR respectively). The specific surface area was determined using the Brunauer-Emmett-Teller method, decreases with the increment of Fe load in the matrix due to possible pore blockage. The values of Fe, Si and Al obtained by ICP were very similar to the theoretical values. The catalytic activity of the materials was evaluated in the photodegradation of methyl orange and compared with the zeolitic matrix without the Fe addition. The results show that the catalytic activity increases with the increment of Fe amount in the catalyst. The increase in the degradation of the catalysts is assigned to the complex Fe(OH)2+, that when is illuminated generates OH? radicals, which is assigned as the main responsible of the degradation and discoloration of methyl orange. The catalysts can be easily recovered and reused in at least 6 cycles, without significant loss of activity.