Dioxin and 1,2-dichlorobenzene adsorption in aluminosilicate zeolite Beta

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• 作者：Laetitia Bullot ; Maher Ben Abda ; Angélique Simon-Masseron ; T. Jean Daou…
• 关键词：Beta zeolite ; Dioxin ; Chlorobenzene ; Adsorption
• 刊名：Adsorption
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：23
• 期：1
• 页码：101-112
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Industrial Chemistry/Chemical Engineering; Surfaces and Interfaces, Thin Films; Engineering Thermodynamics, Heat and Mass Transfer;
• 出版者：Springer US
• ISSN：1572-8757
• 卷排序：23

文摘

The influence of sodium cations content in zeolite Beta crystals of different sizes (between 200 nm and 2 μm) on the adsorption of pollutants (dioxin and polychlorobenzene) is investigated. In this study, protons which balance the negative charge of the zeolitic framework are partially replaced by sodium cations. Chemical, structural and textural analyses performed on the exchanged crystals indicate that the exchange rates reached 75–80 % and that the structure of zeolites is preserved. Adsorptions of pollutants in zeolite Beta samples were successfully carried out using 1,2-dichlorobenzene (gas phase) and 2,3-DiChloroDibenzo-p-Dioxin: 2,3-DCDD (liquid phase) but reveal different behaviors. Indeed, all samples adsorb the same amount (around 7 molecules) of 1,2-dichlorobenzene per unit-cell of zeolite, whereas the dioxin adsorption amounts increase with the amount of sodium cations. Compared to their protonic forms, the dioxin adsorption capacities were multiplied by a factor of 1.3 for the sodium exchanged small crystals (size between 200 nm and 1 μm) and by a factor of 4 for the sodium exchanged microcrystals (size between 1 and 2 μm) for an equilibrium concentration of 2,3-DCDD of 0.5 mmol/L in both cases.