[Stability of HDTMA modified montmorillonite]

In order to probe the stability of organic montmorillonite, the nature montmorillonite was modified with hexadeeyltrimethylammonium (HDTMA) in different cation exchange capacity (CEC). The results of experiments showed that the stability of modified montmorillonite declined as its CEC was big and HDTMA was desorbed from 1.0 CEC modified montmorillonite. HDTMA bound to the montmorillonite surface was resistant to temperature(70 degrees C) and instable to strong ultrasonic and to vibrational intensity(180 r/min). The result also indicated that the stability of modified montmorillonite increased to NaCl(1.8 mol/L) but decreased to CaCl2 (1.8 mol/L) and modified montmorillonite was more stable in high-pH environment(12.00) than in low-pH environment(2.06). On the basis of the results of these studies, low CEC modified montmorillonite appeared suitable as a sorbent for wastewater chemical treatment and as carrier for wastewater biotreatment in low stir environment.