HE Zi-sen 1,2, LIANG Xiao-liang 1, HE Hong-ping 1, ZHU Jian-xi 1, YUAN Peng 1
(1. Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China;
2. University of Chinese Academy of Sciences, Beijing 100049, China)
Abstract: In most natural magnetite, iron cations are usually isomorphously substituted by transitional metal cations. Some substitutions vary the surface reactivity of magnetite, and accordingly affect its catalytic activity in the degradation of organic pollutants. In this study, a series of chromium-substituted magnetite were synthesized by melting and characterized by X-ray diffraction (XRD) and X-ray absorption fine structure spectroscopy (XAFS). The obtained magnetite samples have a spinel structure, where Cr3+ occupies the octahedral sites in magnetite structure. Cr-substitution noticeably improved the degradation of acid orange Ⅱ by magnetite by way of a heterogeneous Fenton reaction. The degradation process followed the pseudo-first-order kinetic reaction. After 160 min of reaction, 40% of acid orange Ⅱ was mineralized.
Key words: chromium-substituted magnetite; XAFS; UV-Fenton; Acid OrangeⅡ
ACTA MINERALOGICA SINICA Vol. 34, No. 4, 2014, Page 439-445
