Postgraduate Program in Mining, Metallurgical and Materials Engineering, Federal University of Rio Grande do Sul., Porto Alegre 91501-970, Brazil.
Postgraduate Program in Engineering of Processes and Technologies, University of Caxias do Sul., Caxias do Sul 95070-560, Brazil.
Langmuir. 2021 Mar 16;37(10):3180-3188. doi: 10.1021/acs.langmuir.1c00123. Epub 2021 Mar 5.
The objective of this work was to characterize and study the behavior of the adsorption process of cellulose/biochar cryogels through isotherm models and adsorption kinetics. The cryogels were produced from a cellulose suspension obtained by mechanical fibrillation of 0.75 and 1.5% w/w unbleached long-fiber cellulose of the species. Into this suspension, 5, 10, and 20% w/w (relative to cellulose mass) biochar were added; then, the suspension was frozen and freeze-dried. After this, 2 mL of methyltrimethoxysilane (MTMS) was deposited on the cryogels. Characterization analyses were performed on the cryogels, including specific mass and porosity and sorption capacity, in addition to the study of adsorption kinetics and isotherms. The cryogels showed a porosity of above 90% and a specific gravity of less than 0.035 g cm. The heterogeneous sorption capacity varied according to the concentration of cellulose used, and with the addition of 5% w/w biochar in the cellulose cryogel, the highest sorption capacity was obtained, 73 g g of petroleum and 54 g g of SAE20W50 oil. In the study of adsorption isotherms, the Freundlich model best fitted the process. Therefore, it was concluded that the process of petroleum adsorption by the cellulose cryogel occurs in multiple layers. In addition, the cellulose/biochar cryogel developed in the present work is suitable for use in the adsorption of organic liquids.
本工作的目的是通过吸附等温线模型和吸附动力学来表征和研究纤维素/生物炭冷冻凝胶的吸附过程的行为。通过机械纤维化 0.75 和 1.5%w/w 的未漂长纤维纤维素 获得纤维素悬浮液来制备冷冻凝胶。向该悬浮液中加入 5%、10%和 20%w/w（相对于纤维素质量）的生物炭；然后，将悬浮液冷冻并冻干。之后，将 2 毫升甲基三甲氧基硅烷（MTMS）沉积在冷冻凝胶上。对冷冻凝胶进行了特性分析，包括比质量和孔隙率以及吸附能力，此外还研究了吸附动力学和吸附等温线。冷冻凝胶的孔隙率大于 90%，比重小于 0.035 g cm。非均相吸附能力根据使用的纤维素浓度而变化，并且在纤维素冷冻凝胶中添加 5%w/w 的生物炭时，获得了最高的吸附能力，石油的 73 gg 和 SAE20W50 油的 54 gg。在吸附等温线的研究中，Freundlich 模型最适合该过程。因此，可以得出结论，纤维素冷冻凝胶对石油的吸附过程是多层发生的。此外，本工作中开发的纤维素/生物炭冷冻凝胶适用于有机液体的吸附。
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