Properties of the Clinoptilolite: Characterization and Adsorption Tests with Methylene Blue

In this work, the physico-chemical properties of clinoptilolite (a natural zeolite) were analyzed by complementary techniques including X-ray diffractogram, N2 physisorption at -196 °C, FESEM and EDX analysis. Zeolite is classified as a mesoporous material (cavities≈ 15 nm) with a specific surface area of 36 m2 g-1 . The porous size distribution shows a peak in the mesoporous region. This zeolite is characterized by anhedral particles assembled on top of one another: this is a characteristic of material growth by magma with impurities (Mordenite) in the pores. The presence of impurities was evidenced with EDX analysis (Fe=0.68% at, Mg=0.47% at.). Then, the adsorption tests were performed with two solutions of methylene blue (MB) at different concentrations (namely 250 and 500 mgL-1). The results showed that the adsorption of the dye is more efficient in the case of250 mg L-1 concentration, with an abatement of 96% after 2h. The abatement corresponding to the higher concentration of MB is about 92.5% after 2h. The kinetic order of MB on clinoptilolite was calculated. The results suggest a second order reaction. In the future, clinoptilolite will be studied for the abatement of metal ion solutions in order to be used as a molecular sieve in the waste water treatment field.