表面活性剂对多壁碳纳米管吸附磺胺二甲嘧啶的影响

Effect of surfactants on the sorption characteristics of sulfadimidine onto multi-walled carbon nanotubes

碳纳米材料在吸附有机污染物方面有很好的应用前景,表面活性剂和抗生素是近年来倍受关注的两类新兴有机污染物.以多壁碳纳米管(MWNTs)为吸附剂,磺胺类抗生素磺胺二甲嘧啶(SM2)为模型化合物,采用批量平衡法研究了表面活性剂共存时对SM2在MWNTs上吸附行为的影响.实验表明:准二级动力学方程能很好地描述SM2在MWNTs上的吸附动力学过程;在吸附等温线实验中,阳离子表面活性剂CTAB在低浓度时抑制SM2在MWNTs上的吸附,高浓度时显著促进SM2的吸附,而阴离子表面活性剂SDBS及非离子表面活性剂Tween-60均对SM2在MWNTs上的吸附起到抑制作用;在离子强度对CTAB和SM2竞争吸附的影响实验中发现,离子强度越高,CTAB对SM2在MWNTs上吸附的促进作用越强.

Multi-walled carbon nanotubes （MWNTs） is a good candidate for the sorption of toxic organic pollutants. Surfactants and antibiotics are two kinds of new-emerging organic pollutants that have been received much attention in recent years. In this paper, MWNTs was used as adsorbent and sulfadimidine （ SM2 ） as model compound to investigate the effect of various surfactants on the sorption behavior of SM2 onto MWNTs employing batch experiments. The results showed that the sorption kinetics of SM2 in the presence of various surfactants was well described by a pseudo-second-order rate model. At low concentrations, the cationic surfactant （CTAB） inhibited the sorption of SM2 onto MWNTs while promoted the sorption at high concentrations. Both the anionic surfactant SDBS and non-ion surfactant Tween-60 inhibited the sorption of SM2 onto MWNTs. Ionic strength promoted the facilitation of CTAB on the sorption of SM2, and the higher of the ionic strength,the stronger of the facihtating effect.