CTMAB改性凹凸棒土对磺胺嘧啶的吸附研究

Adsorption Study of Sulfadiazine by CTMAB Modified Attapulgite

以江苏盱眙和甘肃白银两地出产的凹凸棒土(ATP)为基底物质,用十六烷基三甲基溴化铵(CTMAB)对两种凹凸棒土进行改性,分别制备了10倍阳离子交换容量的CTMAB-江苏凹土和5倍阳离子交换容量的CTMAB-白银凹土两种改性吸附剂。通过批量平衡吸附实验研究了两种吸附剂对磺胺嘧啶(SD)的吸附效果,由动力学实验可知CTMAB-江苏凹土对SD有更好的吸附效果,吸附过程符合拟二级动力学模型。CTMAB-江苏凹土对SD的吸附过程可用Langmuir模型拟合,最大吸附容量为12.440 mg/g。SD浓度越高,越有利于CTMAB-江苏凹土对SD的吸附。pH值为弱酸性和中性时有利于CTMAB-江苏凹土对SD的吸附。腐殖酸浓度大于10 mg/L时会严重影响CTMAB-江苏凹土对SD的吸附。

In this experiment,attapulgite(ATP)produced in Xuyi,Jiangsu and Baiyin,Gansu were used as the base material,and two kinds of attapulgite were modified with cetyltrimethylammonium bromide(CTMAB),respectively.Two modified adsorbents,CTMAB-Jiangsu attapulgite with 10 times the cation exchange capacity and CTMAB-silver attapulgite with 5 times the cation exchange capacity were made.The adsorption effect of the two adsorbents on sulfadiazine(SD)was studied by batch equilibrium adsorption experiments.Batch adsorption experiments showed that the adsorption capacity of CTMAB-Jiangsu attapulgite was hither compared to the CTMAB-Baiyin attapulgite for the SD.The sorption kinetic of SD on CTMAB-Jiangsu attapulgite was best described by the pseudo second-order model.Equilibrium data were best represented by the Langmuir model,which had the maximum adsorption capacity of 12.440 mg/g.The adsorption process was pH dependent and the strong adsorption capacity was obtained under faintly acid and neutral condition.The adsorption capacity increased with the initial SD concentration but decreased with increasing solution humic acid(HA),while the concentration of HA was above10 mg/L.