Chemical Activation of Spent Diatomaceous Earth by Alkaline Etching in the Preparation of Mesoporous Adsorbents

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• 作者：Wen-Tien Tsai ; Kuo-Jong Hsien ; and Chi-Wei Lai
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2004
• 出版时间：November 10, 2004
• 年：2004
• 卷：43
• 期：23
• 页码：7513 - 7520
• 全文大小：235K
• 年卷期：v.43,no.23(November 10, 2004)
• ISSN：1520-5045

文摘

This work was to study the activation regeneration of spent diatomaceous earth (SDE) for thepreparation of mesoporous silica adsorbents by using alkaline activation method. Under theexperimental conditions investigated, it was found that the alkaline activation method by sodiumhydroxide under the controlled conditions significantly etched to proceed inwardly to the interiorof the existing pore structure in the clay minerals, leaving a framework possessing a largeBrunauer-Emmett-Teller surface area (over 100 m²/g) and total pore volume (over 0.3 cm³/g).The results indicated that these samples are type IV with a hysteresis loop. This observationwas also in close agreement with the examinations on the scanning electron microscopy, X-raydiffraction, and Fourier transform infrared. Further, the adsorption rate of methylene blue ontothe resulting clay adsorbent can be well described with the pseudo-second-order reaction model.The physical properties of the diatomaceous earth and resulting adsorbent were also consistentwith the parameters obtained from the fittings of the common isotherms (Langmuir andFreundlich).