摘要
为了探究十二烷基二甲基甜菜碱(BS-12)在水合针铁矿(α-FeOOH)表面的吸附过程和机理,在不同pH值、离子强度以及温度下采用批处理法研究了针铁矿对BS-12的吸附特征;并对BS-12在针铁矿表面的吸附机制进行了探讨.研究结果表明:针铁矿对BS-12的吸附平衡时间约为8 h,吸附过程符合伪二级动力学模型,吸附速率受化学吸附机理控制.Freundlich等温吸附模型能较好地描述针铁矿对BS-12的吸附,pH值对针铁矿吸附BS-12影响显著,主要取决于针铁矿的电荷零点和BS-12的等电点;离子强度的增加对BS-12的吸附有促进作用;温度的升高促进BS-12的吸附.热力学参数结果表明,针铁矿对BS-12的吸附是一个具有熵增和焓增特征的自发性吸热过程.BS-12在针铁矿表面的吸附是一个较慢发生的吸热的化学吸附的过程,主要吸附机制为化学键作用和疏水结合模式.
To explore the process and the mechanism of dodecyl bataine(BS-12)adsorption on the goethite,batch experiments were carried out under different contact time,pH,ionic strengths and temperatures.The adsorption kinetics and thermodynamics were studied.The results show that the adsorption equilibrium time of BS-12 on goethite was about 8 hours.The adsorption process can be described by the Pseudo-second-order kinetic model and Freundlich equation with good correlation coefficients.The adsorption was significantly influenced by pH,depending on the pHZPC of the goethite and the isoelectric point of BS-12.The adsorption ability could be enhanced with the increase of ionic strength and the temperature.The thermodynamic parameters analysis results show that the adsorption of BS-12 on goethite was a spontaneous process characterized by entropy and enthalpy.The adsorption of BS-12 on goethite was a slow endothermic process which was regulated by chemical bonding and hydrophobic binding mode.
作者
吴琼
张洋
孟昭福
WU Qiong;ZHANG Yang;MENG Zhaofu(College of Natural Resources and Environment,Northwest A&F University,Yangling 712100;Xi' an Solid Waste Administration,Xi' an 710038;Key Laboratory of Plant Nutrition and Agri-Environment in Northwest China,Ministry of Agriculture,Yangling 712100)
出处
《环境科学学报》
CAS
CSCD
北大核心
2019年第9期3045-3052,共8页
Acta Scientiae Circumstantiae
基金
国家自然科学基金(No.41271244)
