有机改性膨润土的稳定性研究

利用十六烷基三甲基溴化铵(HDTMAB)对膨润土进行有机改性,研究了不同振荡时间、振荡强度、温度、pH以及盐溶液浓度下改性后有机膨润土的稳定性。结果表明,表面活性剂用量为0.6CEC时,改性的膨润土比较稳定。在同一环境因素下,当表面活性剂用量大于0.6CEC时,有机膨润土的稳定性均随着改性剂用量的增加而降低。振荡时间、振荡强度以及反应温度对有机膨润土稳定性影响不明显;酸性条件下会降低有机膨润土的稳定性,而中性、碱性条件下,有机膨润土的稳定性会提高;对于0.6CEC改性的有机膨润土,当NaC l、CaC l2的浓度由0.2 mol/L增加到0.6 mol/L时有机膨润土的稳定性得到了显著的提高,浓度继续增大,稳定性下降。所以当外界NaC l或CaC l2浓度为0.6 mol/L时,0.6CEC改性的有机膨润土相对0.8CEC以及1.0CEC改性的膨润土稳定,可用做废水处理的吸附剂,且无二次污染。

Study on stability of organo modified bentonite

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.