摘要
应用阳离子表面活性剂十六烷基三甲基溴化铵(HDTMA)、溴代十六烷基吡啶(CPB)、四乙基溴化铵(TEA)和四丁基溴化铵(TBA)分别对凹凸棒石原土进行改性,研究有机改性凹凸棒土对水中邻硝基苯酚的吸附作用.结果表明,四种改性土对水中邻硝基苯酚的吸附在较短的时间内即基本达到平衡,且对水中邻硝基苯酚的吸附去除率与改性土的有机碳含量呈明显的正相关,同样条件下其去除能力大小的顺序是CPB改性土(HDTMA改性土(TBA改性土(TEA改性土;当体系pH值大于邻硝基苯酚的pKa时,CPB改性土对邻硝基苯酚的吸附能力明显增强;CPB改性土对邻硝基苯酚的吸附过程更适合用Henry吸附等温线进行描述,该吸附过程的主要机制是分配作用;CPB改性土对邻硝基苯酚的吸附过程是吸热反应,该吸附过程中无化学键力和配位基交换力等强作用力;阴离子表面活性剂十二烷基苯磺酸钠(SDBS)的存在抑制了CPB改性土对邻硝基苯酚的吸附.
Attapulgite were respectively by modified by cationic surfactants HDTMA, CPB, TEA and TBA. The sorption of o-nitrophenol in water by these four modified attapulgites were studied, and the effects of temperature, pH and different concentration of sodium dodecyl benzene sulfonate （SDBS） on o-nitrophenol adsorption in CPB-modified attapulgite were investigated. Results showed that the sorption of o-nitrophenol on the four modified attapulgites can reach the equilibrium in a few minutes. The removal efficiency of o-nitrophenol in water was positively correlated with the organic carbon content of the modified attapulgite and with the removal efficiency decreasing in the order CPB-modified attapulgite 〉 HDTMA-modified attapulgite 〉 TBA-modified attapulgite 〉 TEA-modified attapulgite. The removal efficiency of o-nitrophenol by CPB- modified attapulgite increased rapidly while the pH 〉 pKa. The sorption isotherm of o-nitrophenol fitting for Henry＇s isotherms equation showed that partition mechanism accounted for the removal of phenol from water by CPB-modified attapulgite. The sorption process was endothermic reaction, without strong action force of ligand-exchange and chemical bonding; The removal efficiency of o-nitrophenol declines with the increase of the concentration of SDBS.
出处
《环境化学》
CAS
CSCD
北大核心
2007年第3期339-342,共4页
Environmental Chemistry
基金
江苏省科学基金(BK2005220)资助项目
