改性膨润土对水体中多环芳烃的吸附  

Adsorption of polycyclic aromatic hydrocarbons from aqueous solutions using modified bentonite

作　　者：史兵方[1] 左卫元[1] 仝海娟[1] 

机构地区：[1]百色学院化学与生命科学系,广西百色533000

出　　处：《环境工程学报》2015年第4期1680-1686,共7页Chinese Journal of Environmental Engineering

基　　金：国家自然科学基金资助项目(41163007);广西自然科学基金项目(2012GXNSFAA053036);广西教育厅项目(2013LX156;201010LX505)

摘　　要：改性膨润土被广泛地应用于吸附水体中重金属离子和有机污染物,但关于改性膨润土吸附水体中多环芳烃混合物的动力学研究鲜见报道。利用十二烷基三甲溴化铵和十二烷基磺酸钠对膨润土进行改性,并将之应用于吸附水体中萘、蒽、菲和芘4种多环芳烃,考察了吸附剂投加量、时间和温度等条件对吸附效果的影响。实验结果表明,在25℃、吸附时间40 min、起始浓度为1.25 mg/m L、改性膨润土的投加量为4 g/L的条件下,该吸附剂对萘、蒽、菲和芘的吸附率分别为99.1%、99.6%、98.7%和98.9%。改性膨润土对水体中4种多环芳烃的吸附机理服从准二级动力学方程,该吸附剂吸附等温线服从Langmuir方程。Modified bentonites have been widely recognized as potential sorbents to remove toxic metals or organic pollutants from aqueous solution. Few reports,especially on the adsorption kinetics of polycyclic aromatic hydrocarbons( PAHs),are available for PAHs removal by modified bentonite. In this study,crude bentonite was modified with dodecyl trimethyl ammonium bromide( DTAB) and sodium dodecylbenzenesulfonate( SDBs). The modified bentonite was used to adsorb naphthalene,anthracene,phenanthrene,and pyrene from aqueous solution.The influences of some parameters such as modified bentonite dosage,contact time,and temperature on the naphthalene,anthracene,phenanthrene,and pyrene removal by the modified bentonite were studied. Results showed that the maximum removal rates of naphthalene,anthracene,phenanthrene,and pyrene were 99. 1%,99. 6%,98. 7%,and 98. 9%,respectively,under the following conditions: temperature of 25℃,contact time of 40 min,the four PAHs initial concentration of 1. 25 mg / m L,and modified bentonite dosage of 4 g / L. All results suggest that the sorption of the four PAHs by modified bentonite followed the second-order kinetics model very well. In addition,the Langmuir model gave an acceptable fit to the experimental data.

关 键 词：天然膨润土 改性 吸附 动力学 多环芳烃 

分 类 号：X52[环境科学与工程—环境工程]