Adsorption Properties of Two Hydrazone Compounds Modified MCM-41 towards Cr（Ⅵ）

Two kinds of novel hydrazone compounds, 2-oxo propionic acid-4-methyl benzoyl hydrazone synthesis (hydrazone1) and 2-oxo propionic acid-4-nitrobenzene hydrazone (hydrazone 2), were synthesized and characterized by infrared spectroscopy and X-ray diffraction methods. Then they were used to modify MCM-41 molecular sieve by physical impregnation method. Adsorption properties of two hydrazone compounds modified MCM-41 towards Cr (Ⅵ) were tested and the influencing factors were studied such as adsorption time, pH, mass of adsorbent and temperature. In addition, thermodynamic and kinetic fitting of adsorption process were also carried out. The results showed that the proper conditions for modified MCM-41 to adsorb Cr (Ⅵ) were when the adsorption time was 40 min, the dosage of modified MCM-41 was 0.3 g, solution pH was 6, and the solution temperature 20 ℃. Removal rates of MCM-41-hydrazone 1 and MCM-41-hydrazone 2 towards Cr (Ⅵ) could reach to 97.6% and 98.2%, respectively. The adsorption process was an exothermic and entropy decreasing non spontaneous reaction.The adsorption processes satisfied simple pseudo-first-order kinetics and quasi secondary-order kinetics.