College of Chemistry and Chemical Engineering, State Key Laboratory of Applied Organic Chemistry, Institute of Biochemical Engineering and Environmental Technology, Lanzhou University, Lanzhou 730000, PR China.
J Hazard Mater. 2009 Dec 30;172(2-3):1357-64. doi: 10.1016/j.jhazmat.2009.08.004. Epub 2009 Aug 8.
In this study, nanoscale Fe(0) was immobilized in and on poly(vinyl alcohol) (PVA) microspheres by the inverse suspension crosslinked method. Two different sizes of Fe(0)/PVA microspheres were synthesized in the presence and absence of dispersant. The chelating action between Fe(2+) and PVA was identified by Fourier transform infrared and X-ray photoelectron spectroscopy. The morphology and distribution of the obtained Fe(0)/PVA microspheres were characterized by environmental scanning electron microscope, energy-dispersive X-ray spectrometry, and X-ray diffraction. Nanoscale Fe(0) particles were mostly dispersed over the surface of the microspheres. They were distributed more homogeneously on the surfaces of Fe(0)/PVA microspheres with diameter of 600-700 microm than those with diameter of 10-12 microm. The nitrobenzene (NB) reduction reactions followed pseudo-first-order kinetics. The normalized surface rate constants (k(SA)) values were determined to be 0.162 L h(-1)m(-2) for L-Fe(0)/PVA microspheres, 0.098 L h(-1)m(-2) for S-Fe(0)/PVA microspheres, and 0.023 L h(-1)m(-2) for nanoscale Fe(0) particles. Furthermore, with the analysis of the products by GC/MS, possible reductive pathways of NB by Fe(0)/PVA microspheres were suggested. The recovery rates of iron in microspheres were determined to be 81.17% for large Fe(0)/PVA and 60.31% for small Fe(0)/PVA.
在这项研究中，纳米级 Fe(0) 通过反悬浮交联法固定在聚乙烯醇（PVA）微球中。在有无分散剂的情况下合成了两种不同尺寸的 Fe(0)/PVA 微球。傅里叶变换红外和 X 射线光电子能谱证实了 Fe(2+)与 PVA 之间的螯合作用。通过环境扫描电子显微镜、能量色散 X 射线光谱和 X 射线衍射对所获得的 Fe(0)/PVA 微球的形态和分布进行了表征。纳米级 Fe(0) 颗粒主要分散在微球的表面上。在直径为 600-700 微米的 Fe(0)/PVA 微球表面上，纳米级 Fe(0) 颗粒的分布比在直径为 10-12 微米的 Fe(0)/PVA 微球表面上更加均匀。硝基苯（NB）的还原反应遵循准一级动力学。归一化表面速率常数（k(SA)）值分别为 L-Fe(0)/PVA 微球为 0.162 L h(-1)m(-2)，S-Fe(0)/PVA 微球为 0.098 L h(-1)m(-2)，纳米级 Fe(0) 颗粒为 0.023 L h(-1)m(-2)。此外，通过 GC/MS 对产物进行分析，提出了 Fe(0)/PVA 微球还原 NB 的可能途径。微球中铁的回收率分别为大 Fe(0)/PVA 为 81.17%，小 Fe(0)/PVA 为 60.31%。
