CTMAB/CPAM复合改性膨润土吸附水中苯酚和硝基苯

Sorption of Phenol and Nitrobenzene in Water by CTMAB/CPAM Organobentonites

用十六烷基三甲基溴化铵(CTMAB)和阳离子型聚丙烯酰胺(CPAM)改性膨润土,制得系列CTMAB-膨润土(C-Bt)、CPAM-膨润土(P-Bt)和复合改性膨润土(C/P-Bt).采用XRD分析了各类有机膨润土的底面间距,并比较了它们吸附水中苯酚和硝基苯的性能.结果显示,C/P-Bt的底面间距大于相应的C-Bt和P-Bt,表明CTMAB与CPAM能同时层插到膨润土层间.C/P-Bt吸附性能优于C-Bt及C-Bt加P-Bt,在相同平衡浓度下(苯酚为7 045 mg/L,硝基苯为409 mg/L),60C/4%P-Bt对苯酚和硝基苯的吸附量分别为150 mg/g和69 mg/g,吸附量比60C-Bt分别提高了26%和28%,比60C-Bt加4%P-Bt分别提高了22%和26%,表现出明显协同吸附效应.这说明CTMAB在C/P-Bt层间的排列模式受CPAM的影响,形成了对有机物亲和能力更强的吸附介质.该新型有机膨润土在有机污染控制中有良好的应用前景.

A series of cetyltrimethyl amonium bromide bentonite （C-Bt）, cationic polyacrylamide bentonite （P-Bt） and composite organobentonite （C/P-Bt） were synthesized by modifying bentonite with cetyltrimethyl ammonium bromide （CTMAB） and/or cationic polyacrylamide （CPAM）. The basal spacings of the obtained organobentonites were analyzed with XRD. The sorption capacities of phenol and nitrobenzene to these organobentonites from water were examined. The results showed that the basal spacing values of C/P- Bt were larger than those of C-Bt and P-Bt, which indicated a simultaneous intercalation of bentonite interlayers by CTMAB and CPAM. The sorption capacity of C/P-Bt was better than that of C-Bt. Under the same equilibrium concentration （7 045 mg/L for phenol and 409 mg/L for nitrobenzene） , the sorbed amounts of phenol and nitrobenzene on 60C/4% P-Bt were 150 and 69 mg/g, which enhanced 26% and 28% respectively comparing with those on 60C-Bt. Furthermore, the sorption capacity of 60C/4% P-Bt was better than the sum of 60C-Bt and 4% P-Bt, and the sorbed amounts of phenol and nitrobenzene enhanced 22% and 26% respectively, showing an obvious synergistic sorption effect. An explanation for these results was that the arrangement model of CTMAB within the C/ P-Bt interlayers was affected by CPAM, which led to the formation of organic phase with better affinity to the organic compounds. This novel organobentonites may have wide applications in organic pollution control.