插层水滑石的组装及对对硝基甲苯的吸附

采取一步改性、离子交换和焙烧复原3种方法实现阴离子表面活性剂十二烷基硫酸钠(SDS)插层Mg3Al-NO3-水滑石(HT)的组装,通过XRD、FT-IR、TEM、TOC、NMR等表征手段对插层水滑石(SDS-HT)进行表征.研究了SDS-HT吸附对硝基甲苯的性能及影响因素,探讨了其吸附机理,并定量描述了分配作用和表面吸附对总吸附量的相对贡献.结果表明,3种插层方法均制备了层状结构良好的阴离子黏土,其中焙烧复原法制备的样品SDS含量最多. SDS在SDS-HT中形成了增溶(分配)作用较强的有机相,并影响表面吸附作用和分配作用在吸附过程中的贡献率.3种样品对对硝基甲苯均有良好的吸附作用,在本研究浓度范围内,对硝基甲苯的吸附主要由表面吸附作用提供,焙烧复原法所得样品平衡浓度为162mg/L时的吸附量最大,为44.5mg/g.

Assembly of SDS intercalcted hydrotaleite and the adsorption of p-nitrotoluene

Dodecyl sulfate sodium intercalated Mg3Al-NO3- hydrotalcite (SDS-HT) was assembled by one step synthesis, anion exchange and rehydration of the calcined hydrotalcite. The structural properties of SDS-HT were characterized by XRD, FT-IR, TEM, TOC and NMR. The adsorption properties of p-nitrotoluene on SDS-HT and the adsorption mechanism was investigated. In addition partition and adsorption contributions to the adsorption amount of p-nitrotoluene on the SDS-HT were quantitatively described. 3 samples prepared by different modification methods had the typical layered double hydroxides structure, and the sample synthesized by rehydration of the calcined hydrotalcite had the highest content of SDS. Anion surfactant SDS formed organic phase in SDS-HT, and the organic phase affected the ration of adsorption of p-nitrotoluene between the surface adsorption and partition. All samples adsorbed p-nitrotoluene effectively, and the effect of adsorption mainly resulted from surface adsorption. The maximum adsorption was 44.5mg/g, which was achieved at 162mg/L p-nitrotoluene aqueous solution on the sample of rehydration of the calcined hydrotalcite.