摘要
采用溶液共混和相转移技术,经二乙烯三胺五乙酸(DTPA)和三聚氰胺(MA)共价键合作用,制备了具有螯合配位作用的改性聚偏氟乙烯共混膜(DTPA-MA/PVDF),研究了DTPA-MA/PVDF共混膜对水溶液中Ni2+的吸附性能、吸附热力学及吸附动力学。结果表明,DTPA-MA/PVDF共混膜对Ni2+具有优良的吸附性能,吸附量随温度升高而下降。热力学参数ΔG0<0、ΔH0<0、ΔS0>0,证实了DTPA-MA/PVDF共混膜对Ni2+的吸附为自发的放热过程。DTPA-MA/PVDF共混膜对Ni2+的等温吸附较好地符合Langmuir等温吸附模型,D-R等温吸附表明该吸附过程为离子交换反应,该吸附过程的动力学符合准二级动力学方程。经4次吸附/脱附循环后,DTPA-MA/PVDF共混膜对Ni2+吸附量仍大于0.025mg/cm2,脱附率仍超过90%。
The blended polyvinylidene fluoride membrane was prepared by anchoring the chelating agent diethylenetriamine-pentaacetic acid （DTPA） to the membrane via the amide covalent bond reaction between DTPA and melamine（MA）, using the combination of solution blending technique and phase inversion process. The adsorption property, the adsorption isotherm and the batch sorption kinetics of Ni^2＋ by the DTPA-MA/PVDF blended membrane were studied. The results of simulation indicate that the DTPA-MA/PVDF membrane possesses an excellent adsorption property of Ni^2＋, and the adsorption capacity of the blended membrane decreases with the increase of temperature. The value of △G^0 〈0, △H^0 〈0, and △S^0 〉0, shows that the adsorption of Ni^2＋ by the DTPA-MA/PVDF membrane is a spontaneous and exothermic process. The isotherms of adsorption of Ni^2＋ by the blended membrane fit better to Langmuir isotherm model. The results of D-R adsorption isotherm show that the adsorption mechanism is assumed to be an ion exchange between the nickel ion and the chelating functional group of the blended membrane. The batch sorption kinetics accords with the pseudo-second-order kinetics model. For the DTPA-MA/PVDF membrane the adsorption capacity of Ni^2＋ is more than 0.025 mg/cm^2, and the desorption efficiency is beyond 90% after 4 adsorption/desorption processes.
出处
《唐山师范学院学报》
2010年第2期16-20,共5页
Journal of Tangshan Normal University
基金
河北省教育厅自然科学研究计划项目(Z2008134)
关键词
二乙烯三胺五乙酸
三聚氰胺
聚偏氟乙烯共混膜
重金属离子
等温吸附
动力学方程
Diethylenetriaminepentaacetic acid
melamine
polyvinylidene fluoride blended membrane
heavy metal ion
adsorption isotherm
kinetics equation
