Hydrophobic Fe-Zeolites for Removal of MTBE from Water by Combination of Adsorption and Oxidation

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• 作者：Rafael Gonzalez-Olmos ; Frank-Dieter Kopinke ; Katrin Mackenzie ; Anett Georgi
• 刊名：Environmental Science & Technology (ES&T)
• 出版年：2013
• 出版时间：March 5, 2013
• 年：2013
• 卷：47
• 期：5
• 页码：2353-2360
• 全文大小：336K
• 年卷期：v.47,no.5(March 5, 2013)
• ISSN：1520-5851

文摘

Several zeolites were evaluated as adsorbents for the removal of MTBE from water in a screening process. It was observed that the SiO₂/Al₂O₃ molar ratio is a decisive factor for the adsorption properties, at least in the case of ZSM5 zeolites. ZSM5 zeolites with SiO₂/Al₂O₃ ratios >200 were found to provide the best sorption properties for MTBE. To design a combined sorption/reaction method, regeneration of the loaded zeolites by selected advanced oxidation processes (AOP) was studied: (1) Fenton treatment using H₂O₂ with dissolved iron salts and (2) heterogeneous Fenton-like oxidation with Fe immobilized on the zeolites. The first was ineffective in regenerating loaded zeolites. However, heterogeneous catalysis using Fe species immobilized on the zeolite by liquid ion exchange was markedly more effective. Although these hydrophobic zeolites have a low ion exchange capacity, resulting in iron loadings of 鈮?.09 wt %, it was possible to obtain sufficiently active catalysts. Hydrophobic Fe-zeolites can therefore be regarded as promising materials for the removal of MTBE from water, since they allow the combination of efficient adsorption and oxidative degradation of MTBE by H₂O₂. In contrast to the homogeneous catalysis by dissolved iron ions, these heterogeneous catalysts work at near-neutral pH and can be easily reused. Fe-zeolites as adsorbents/catalysts showed a good stability in both batch and column experiments.