摘要
为提高双子表面活性剂改性蛭石的吸附性能,用碳酸钠对天然蛭石进行同质化处理,合成芳香反离子季铵盐型双子表面活性剂(GC-S)并作为改性剂,通过水热法对钠基蛭石(Vt-Na)进行插层处理,制备有机蛭石(GC-S-Vt)。通过核磁共振氢谱(1HNMR)、X射线粉末衍射(XRD)、傅里叶变换红外光谱(FT-IR)、热重(TG)和扫描电子显微镜(SEM)进行表征,考察改性有机蛭石对甲基橙(MO)的吸附效率及表面活性剂含量、pH值对改性有机蛭石对甲基橙的吸附效率的影响。改性后蛭石的亚甲基对称与非对称伸缩振动峰增强表明GC-S成功用于有机蛭石的改性。改性后的GC-S-Vt层间距增大,这是由于有机反离子修饰的双子表面活性剂增加了蛭石层间距,并提高了其对MO的吸附质量比。当GC-S的添加量为0.8 CEC,温度为25℃时,GC-S-Vt对阴离子染料甲基橙的吸附效率由改性前的2%提高至98.31%。在pH值为5、吸附时间为60 min时,GC-S-Vt对甲基橙的吸附质量比最大。此外,本文还考察了改性有机蛭石对甲基橙的吸附动力学与热力学行为。试验结果发现,甲基橙的吸附符合拟二级动力学模型与Langmuir吸附模型,且GC-S-Vt对甲基橙的吸附属于自发的物理吸附过程。此外,4次吸附-脱附循环后,吸附剂对甲基橙的去除率依旧保持在70%以上,展现出优异的再生性能。因此,改性的有机蛭石GC-S-Vt可作为去除甲基橙的有效吸附剂。
To improve the adsorption performance of vermiculite modified by Gemini surfactant,the modified organic-vermiculite(GC S Vt)was prepared in this work.The natural vermiculite was homogenized with sodium carbonate,obtaining sodium-based vermiculite(Vt Na).The quaternary ammonium salt Gemini surfactant(GC S)was synthesized and was treated as a modifier for intercalation treatment of Vt Na by hydrothermal method,obtaining the GC S Vt.The basic properties of GC S Vt were characterized by Nuclear magnetic resonance hydrogen spectroscopy(1 HNMR),X ray Diffractometer(XRD),Fourier Transform Infrared Spectroscopy(FT IR),Thermogravimetry analysis(TG),and Scanning Electron Microscope(SEM)test.The effect of surfactant content and pH on the adsorption efficiency of the modified organicvermiculite is also evaluated.It is found that the increase of symmetric and asymmetric stretching vibration peaks of methylene of GC S VT demonstrates successful preparation of vermiculite modified by GC S.The layer spacing of modified organic-vermiculite is increased,which is ascribed to the reason that organic counterion-modified Gemini surfactant significantly increases the vermiculite layer spacing,improving the adsorption amount.When the dosage of vermiculite is 0.8 CEC at 25℃,the adsorption efficiency of modified GC S Vt for anionic dye methyl orange is improved to 98.31%,comparing the original adsorption efficiency of 2%of unmodified vermiculite.The maximum adsorption amount of the methyl orange is obtained at pH=5 after 60 min.Then the adsorption kinetics and thermodynamic behavior of methyl orange by modified organic vermiculite are investigated.The experimental results show that the adsorption kinetics law for methyl orange by using GC S Vt is in line with the pseudo-second-order kinetic model and Langmuir model.The adsorption thermodynamic law reveals that the adsorption for methyl orange by GC S Vt is the spontaneous physical adsorption process.In addition,the removal rate of methyl orange is still retained at 70%after four sorptio
作者
贾振福
殷杰蕊
张文龙
薛润
左承未
JIA Zhenfu;YIN Jierui;ZHANG Wenlong;XUE Run;ZUO Chengwei(College of Chemistry and Chemical Engineering,Chongqing University of Science&Technology,Chongqing 401331,China)
出处
《安全与环境学报》
CAS
CSCD
北大核心
2023年第10期3741-3748,共8页
Journal of Safety and Environment
基金
重庆市自然科学基金项目(cstc2021jcyj-msxmX0805)。
关键词
环境工程学
蛭石
有机反离子
甲基橙
吸附
environmental engineering
vermiculite
counter ion
methyl orange
adsorption
