摘要
采用离子交换法制备了十二烷基苯磺酸根(DBS-)和柠檬酸根(Cit3-)复合改性层状双氢氧化物(LDHs),简写为DBS-Cit-LDHs。利用粉末X射线衍射分析、红外光谱分析、比表面积测定以及元素分析等技术手段对样品进行了表征。结果表明,DBS-和Cit3-已柱撑进入LDHs层间。研究了DBS-Cit-LDHs对水中重金属离子Cu2+和有机污染物双酚A(BPA)的协同吸附性能。吸附实验结果表明,DBS-Cit-LDHs能同时高效去除Cu2+和BPA:对Cu2+的强吸附能力缘于DBS-Cit-LDHs层间Cit3-与Cu2+形成了稳定配合物;对BPA的强吸附能力缘于分配作用,且吸附能力与样品比表面积无关。DBS-Cit-LDHs对Cu2+的吸附动力学和热力学分别符合准二级动力学方程和Freundlich等温式;对BPA的吸附分别符合准一级动力学方程和Linear等温式。二者吸附过程的ΔGo和ΔHo均为负值,表明吸附为自发放热过程。
A novel type of adsorptive material, dodecylbenzenesulfonate （DBS）-citrate （Cit）-layered double hydroxide（ LDHs）, DBS-Cit-LDHs, was synthesized by modifying Mg-A1 LDHs with both DBS- and citrate3- anions using ion-exchange method. DBS-Cit-LDHs was characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, low-temperature N2 adsorption, and elemental analysis. The surface property and structure of DBS-Cit-LDHs are significantly ahered from Mg-Al LDHs. Batch adsorption experiments indicate that DBS-Cit-LDHs can simultaneously adsorb biphenol A（BPA） and Cu^2＋ from the mixed solution. The adsorption kinetics of Cu^2＋ and BPA can be well fitted with the pseudo-second order kinetic model and pseudo-first order kinetic model, respectively. The adsorption isotherm of Cu^2＋ and BPA can be well fitted with the Freundlich and Linear equations, respectively. BPA adsorption is attributed to a partition retention mechanism. Cu^2＋ adsorption is dominated by the formation of complexes between Cu^2＋ and citrate^3- anions in the interlayer of DBS-Cit-LDHs. The negative values of △G^0 and △H^0 observed for BPA and Cu^2＋ adsorption confirm the spontaneity and exothermic nature, respectively. These results indicate the potential application of DBS-Cit-LDHs in treating wastewater containing both organic compounds and heavy metals.
出处
《应用化学》
CAS
CSCD
北大核心
2015年第7期816-824,共9页
Chinese Journal of Applied Chemistry
基金
山西省自然科学基金项目(2013011040-8)
国家级大学生创新训练项目(201310122002)
山西省大学生创新训练项目(2014431)
山西省高等学校教学改革项目(J2013104)
山西省教育科学"十二五"规划项目(GH-12086)资助~~
