Preparation of Si-Al/¦Á-FeOOH catalyst from an iron-containing waste and surface-catalytic oxidation of methylene blue at neutral pH value in the presence of H₂O₂

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• 作者：Baoling Yuan^a ; ^{yuanbl@hotmail.com} ; Junge Xu^a ; Xiaoting Li^a ; Ming-Lai Fu^b ; ^{mlfu@iue.ac.cn}
• 关键词：Grinding wheel ash ; Fenton-like reaction ; Iron oxide ; Surface&ndash ; catalytic oxidation ; Non-radical mechanism
• 刊名：Chemical Engineering Journal
• 出版年：2013
• 出版时间：15 June, 2013
• 年：2013
• 卷：226
• 期：Complete
• 页码：181-188
• 全文大小：1014 K

文摘

The tested Si-Al/¦Á-FeOOH composite was prepared by dissolution, precipitation and aging of a high iron-containing grinding wheel ash (GWA). The obtained Si-Al/¦Á-FeOOH composite was characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscope/energy dispersive X-ray spectrometer (SEM/EDS) analyses. The characterized composite was then evaluated for the decolorization of methylene blue (MB) in the presence of H₂O₂ at various pH conditions. The extent of MB decolorization was characterized using UV-Vis spectra, total organic carbon (TOC) and Fourier transform infrared spectroscopy (FTIR). The surface-catalytic oxidation mechanism was discussed and the roles of silica and alumina were also evaluated through preparation of four kinds of catalysts from analytical reagents (ARs). The results showed that ¦Á-FeOOH (75.40 wt % Fe) was the predominate content in Si-Al/¦Á-FeOOH composite with 2.26 wt % Si and 1.02 wt % Al. The Fenton-like process (Si-Al/¦Á-FeOOH composite combined with H₂O₂) can effectively oxidize MB at pH 6.46 % and 72 % of TOC removal can be achieved after 60 min catalytic oxidation. The surface-catalytic oxidation by Si-Al/¦Á-FeOOH/H₂O₂ may proceed mainly through a non-radical mechanism. The introduction of silica played an important role in the enhancement of the ¦Á-FeOOH adsorptive capacity by the inhibition of the formation of crystalline structure of FeOOH, and the introduction of alumina might enhance the ¦Á-FeOOH catalytic activity and also prevent the iron from leaching from Si-Al/¦Á-FeOOH catalyst.