ADSORPTIVE PERFORMANCE OF MCM-41 TOWARDS Hg(II) IN WATER. ADSORPTION AND DESORPTION STUDIES

摘要

MCM-41 mesoporous material was prepared under a standard conditions by using cetyltrimethylammonium bromide as a structure-directing agent and tetraethyl orthosilicate as silica source from the liquid phase at 80 degrees C. Powder X-ray diffraction and scanning electron microscopy used to characterize the product, showed that the MCM-41 material had an average particle size of 110 nm. The synthesized material was used to investigate the effects of acidity, adsorption time, the concentration of Hg2+, adsorbent dosage and temperature on the adsorption of Hg2+. The results showed that the optimal adsorptive conditions were: pH 5.0, m(MCM-41):mHg(2+) 6.67, temperature 20 degrees C and contact adsorption time 60 min, for the initial Hg2+ concentration of 1.0 mg/cm(3). The maximum adsorptive amount of Hg2+ was 56.48 mg Hg2+/g MCM-41. The results of the desorptive effect of three desorption agents such as HCl, HNO3 and HAc showed that the best desorbent was HCl at the concentration of 0.10 mol/dm(3). The highest desorption efficiency was 77.21% for the desorption time 2 h.