Methylene blue adsorption on activated carbon prepared from Posidonia oceanica (L.) dead leaves: Kinetics and equilibrium studies
Methylene blue adsorption on activated carbon prepared from Posidonia oceanica (L.) dead leaves: Kinetics and equilibrium studies
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DOI：
10.1016/j.cej.2010.12.038
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发表时间：
2011-03-15
影响因子：
15.1
通讯作者：
Katsaros, Fotis K.
中科院分区：
文献类型：
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作者：
Dural, Mehmet Ulas;Cavas, Levent;Katsaros, Fotis K.
Posidonia oceanica（L）是地中海的一种特有种，与陆生植物一样，其叶子也会季节性脱落。枯叶作为废弃物大量堆积在海滩上，造成了巨大的环境和经济问题。死生物质为活性炭（AC）的生产提供了丰富的、可再生的和低成本的前体。在这方面，通过化学活化海洋棕（L）枯叶来制备AC。制备过程包括氯化锌浸渍比例高达45%，然后在氮气气氛中在高达873 K的温度下碳化。制备的海洋大球藻P. oceanica（L.）采用扫描电镜和氮气孔隙率仪对活性炭（POAC）进行了研究，并测定了其孔结构特征。关于POAC 45样品，实现了1483 m2/g的比表面积和约1 cm 3/g的总孔体积，同时获得了微孔性和中孔性。考察了POAC在初始浓度、炭用量、pH、温度等条件下对水溶液中亚甲基蓝（MB）的吸附潜力，并确定了最佳实验条件。样品显示相对较快的动力学在约60 min内达到平衡，其遵循二级速率方程，而吸附不受溶液pH的影响。Langmuir模型提供了最好的拟合实验数据和吸附容量随温度的升高而增加。结果表明，前驱体的加入使活性炭在318 K时对亚甲基蓝的吸附容量达到285.7 mg/g。综上所述，海洋原毛藻（P. oceanica（L.））枯叶可作为制备优质活性炭的原料。(C)2010 Elsevier B. V.保留所有权利。
Posidonia oceanica (L) is an endemic species in the Mediterranean Sea, which, like terrestrial plants, loses it leaves seasonally. The dead leaves are accumulated on the beaches in huge quantities as waste material, causing great environmental and economical problems. The dead biomass offers an abundant, renewable and low cost precursor for the production of activated carbon (AC). In that respect ACs were prepared by chemical activation of P. oceanica (L) dead leaves. The preparation process consisted of zinc chloride impregnation at ratios up to 45%, followed by carbonization in nitrogen atmosphere at temperatures up to 873 K. The prepared P. oceanica (L.) activated carbons (POAC) were studied by SEM and Nitrogen porosimetry and the pore structural characteristics were determined. Concerning the POAC45 sample, a specific surface area of 1483 m(2)/g and a total pore volume of about 1 cm(3)/g were achieved, while both microporosity and mesoporosity were obtained. The adsorption potential of POAC for the removal of methylene blue (MB) from aqueous solutions was also investigated under varying conditions of initial concentration, carbon dosage, pH, temperature and the optimum experimental conditions were determined. The samples revealed relatively fast kinetics reaching equilibrium in around 60 min, which follow the second order rate equation, while adsorption was unaffected by the pH of the solution. The Langmuir model provided the best fit to the experimental data and sorption capacity increased with increasing temperature. The results showed that proposed precursor lead to AC with increased sorption capacity for MB reaching a value of 285.7 mg/g at 318 K. In conclusion, P. oceanica (L.) dead leaves can be used as a raw material for preparation of high quality activated carbon. (C) 2010 Elsevier B.V. All rights reserved.