Immobilization of nanoscale Fe(0) in and on PVA microspheres for nitrobenzene reduction

• Published in: Journal of hazardous materials 2009-12, Vol.172 (2-3), p.1357-1364
• Main Authors: Bai, X, Ye, Z F, Qu, Y Z, Li, Y F, Wang, Z Y
• Format: Article
• Language: English
• ISSN: 0304-3894
• DOI: 10.1016/j.jhazmat.2009.08.004

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 600-700km than those with diameter of 10-12km. The nitrobenzene (NB) reduction reactions followed pseudo-first-order kinetics. The normalized surface rate constants (k(S(A) values were determined to be 0.162Lh(-(1m(-(2 for L-Fe(0)/PVA microspheres, 0.098Lh(-(1m(-(2 for S-Fe(0)/PVA microspheres, and 0.023Lh(-(1m(-(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.