HDTMA改性蒙脱土的稳定性

利用十六烷基三甲基溴化铵(HDTMA)改性天然蒙脱土,观察其在不同环境条件下的稳定性.试验结果表明:随着阳离子交换量(CEC)的增加改性蒙脱土在蒸馏水中的稳定性逐渐降低,1.0CEC改性蒙脱土中HDTMA发生解吸.改性蒙脱土在水体中的稳定性随着振荡强度的加强而降低.从室温到70℃对改性蒙脱土的稳定性几乎无影响.超声波处理使改性蒙脱土的稳定性有所降低.NaCl能提高水体中改性蒙脱土的稳定性,而CaCl₂却使其稳定性有所下降.同酸性条件相比,在碱性条件下改性蒙脱土的稳定性更好.因此,废水的温度、pH和无机盐对低改性蒙脱土稳定性的影响都比较小,这为改性蒙脱土处理废水和它的再生提供了可能.同时在较低振荡强度下,改性蒙脱土也许还能成为废水生物处理的载体.

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.