Study on stability of organo modified bentonite
有机改性膨润土的稳定性研究

Cetyltrimethylammonium bromide(HDTMA), as a cationic surfactant, was used for organic modification of bentonite, with study of the stability of organo modified bentonite under such various conditions as shaking time,shaking intensity,temperature,pH and salts. The results showed that 0.6CEC modified bentonite had better stability,and the stability of organobentonite declined when the dosage of surfactant exceeded 0.6CEC under the same conditions. Shaking time, shaking intensity and temperature had little effect on the stability of organobentonite; the stability could be reduced by lower pH, while neutral condition and the higher pH could increase the stability of organobentonite. As for 0.6CEC modified bentonite, the stability of organobentonite greatly enhanced with increasing concentrations of NaCl and CaCl2 from 0.2 mol/L to 0.6 mol/L, but the stability finally decreased if the concentration continued rising. Hence, when the concentration of NaCl and CaCl2 was 0.6 mol/L, the stability of 0.6CEC modified bentonite was better than that of 0.8CEC and 1.0CEC , which could be used as absorbent for treatment of wastewater without second pollution.