改性累托石对苯酚和铬的吸附等温线及分形维数  

ADSORPTION ISOTHERMS AND FRACTAL DIMENSION OF MODIFIED RECTORITE

作　　者：黄韵[1] 马晓燕[1] 朱雅红[1] 

机构地区：[1]西北工业大学理学院应用化学系,西安710072

出　　处：《硅酸盐学报》2005年第11期1381-1384,共4页Journal of The Chinese Ceramic Society

基　　金：西北工业大学研究生创新种子基金(Z200585)资助项目

摘　　要：用十二烷基二甲基苄基氯化铵[C12H25(CH3)2(C6H5CH2)NCl,1227]、十六烷基三甲基溴化铵[C16H33(CH3)3NBr,1631]、十八烷基三甲基溴化铵[C18H37(CH3)3NBr,1831]3种表面活性剂改性天然黏土累托石(rectorite,REC),得到3种有机改性累托石:1227 REC,1631 REC和1831 REC。用3种有机改性累托石对水溶液中有机物苯酚和无机重金属离子Cr(Ⅵ)的吸附实验,对比了它们的吸附等温线及相应的分形模型。实验结果表明:改性REC对苯酚和Cr(Ⅵ)的吸附作用分别是由阴阳离子静电吸引和表面配位反应所引起的。吸附剂的“吸附活性位”的分形维数计算表明:1227 REC和1631 REC对苯酚的分形维数分别是2.85,2.91;1227 REC,1631 REC和1831 REC对Cr(Ⅵ)的分形维数分别是2.65,2.86和2.73。Natural rectorite （REC） was modified with dodecyl benzyl dimethyl ammonium chloride [C12 H25 （CH3）2 （C6Hs - CH2 ） NCI, 1 2271, hexadecyl trimethyl ammonium bromide[C16 H33 （CH3）3 NBr, 16311 and octadecyl trimethyl ammonium bromide [C18 H37 （CH3）3 NBr, 1831], respectively. Then three kinds of organic-modified rectorite were obtained： 1.227 - REC, 1631 -REC, 1831 -REC which were used as adsorbents for phenol or Cr（ VI ） ions in water. A comparison of adsorption isotherms and of the isotherm fractal model shows that the adsorption reactions for phenol and Cr（ VI ） are caused by static electric attraction between the cation and anion and surface complexation reaction respectively. The fractal calculation for active absorption sites of absorbents shows that the fractal dimensions of 1227 - REC and 1631 REC are respectively 2.85 and 2. 91 for phenol and those of 1227 - REC, 1631 REC and 1831- REC are respectively 2. 65, 2.86and2.73 forCr（VI）.

关 键 词：表面活性剂 累托石 苯酚 六价铬离子 分形维数 

分 类 号：TQ424.24[化学工程]