State Key Laboratory Base of Eco-chemical Engineering, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, PR China.
J Hazard Mater. 2013 Sep 15;260:210-9. doi: 10.1016/j.jhazmat.2013.05.019. Epub 2013 May 18.
In this paper, a novel triethylene-tetramine grafted magnetic chitosan was synthesized. The chemical structure and the percentage content of each element of chitosan and its derivatives were characterized by elemental analysis, infrared spectroscopy, solid state (13)C NMR, X-ray diffraction analysis and thermogravimetric analysis, respectively. Their surface topography was observed by the transmission electron microscope. The results of adsorption kinetics and adsorption thermodynamics showed the adsorption mechanism could be better described by the pseudo-second-order equation (R>0.999). The adsorption isotherm was well fitted by the Langmuir equation (R>0.999), and 0<R(L)<1. The maximum adsorption capacity was 370.63 mg/g at the optimized adsorption conditions, which were pH=6, T=298 K, t=1.5h, C(0)=200 mg/L and adsorbent dose is 500 mg/L. The rate-limiting step may be the chemical adsorption rather than mass transport. The adsorbent still exhibited very good adsorption performance after the fifth regeneration cycle. The mechanism for adsorption and desorption was discussed.
本文合成了一种新型的三乙烯四胺接枝磁性壳聚糖。通过元素分析、红外光谱、固态（13）C NMR、X 射线衍射分析和热重分析分别对壳聚糖及其衍生物的化学结构和各元素的百分含量进行了表征。通过透射电子显微镜观察了它们的表面形貌。吸附动力学和吸附热力学的结果表明，吸附机制可以更好地用拟二级方程（R>0.999）来描述。吸附等温线很好地符合朗缪尔方程（R>0.999），且 0<R(L)<1。在优化的吸附条件下（pH=6、T=298 K、t=1.5h、C(0)=200 mg/L 和吸附剂用量为 500 mg/L），最大吸附容量为 370.63 mg/g。限速步骤可能是化学吸附而不是质量传递。吸附剂在经过第五次再生循环后仍表现出非常好的吸附性能。讨论了吸附和解吸的机制。
