Abstract Sisal fibers were employed as cost-effective adsorbent material to remove methylene blue (MB) and reactive black 5 (RB5) dyes from aqueous solutions. The fibers were characterized and the effects of adsorbent dosage and pH were investigated. Kinetic, equilibrium, and thermodynamics were analyzed. Desorption studies were performed and simulated textile effluents were treated with the fibers. The results revealed that the homogeneous surface diffusion model (HSDM) for cylindrical geometry was able to explain the adsorption kinetics, being the diffusion coefficients (DS) of 3.45 and 1.94 × 10−14 cm2 s−1 for MB and RB5, respectively. The BET model was adequate to represent the equilibrium data for MB and RB5. Adsorption capacities reached 553.4 and 310.2 mg g−1 for MB and RB5, respectively. Adsorption was spontaneous and favorable. Chemisorption was involved in the MB adsorption, while, physisorption was dominant for RB5 adsorption. Sisal fibers were efficient to decolorize a simulated effluent, reaching color removal percentage of 85%. It can be concluded that sisal fibers are a promising adsorbent to treat colored effluents, since has low cost, require little processing and possess high adsorption capacity for anionic and cationic dyes.

中文翻译：

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剑麻纤维作为一种替代且具有成本效益的吸附剂，用于从水溶液中去除亚甲蓝和活性黑 5 染料

摘要 剑麻纤维被用作经济高效的吸附材料，可从水溶液中去除亚甲蓝 (MB) 和活性黑 5 (RB5) 染料。对纤维进行了表征，并研究了吸附剂用量和 pH 值的影响。分析了动力学、平衡和热力学。进行解吸研究并用纤维处理模拟的纺织流出物。结果表明，圆柱形几何形状的均匀表面扩散模型 (HSDM) 能够解释吸附动力学，MB 和 RB5 的扩散系数 (DS) 分别为 3.45 和 1.94 × 10−14 cm2 s−1。BET 模型足以代表 MB 和 RB5 的平衡数据。MB 和 RB5 的吸附容量分别达到 553.4 和 310.2 mg g-1。吸附是自发且有利的。MB吸附涉及化学吸附，而RB5吸附则以物理吸附为主。剑麻纤维可以有效地对模拟污水进行脱色，达到 85% 的脱色率。可以得出结论，剑麻纤维是一种很有前途的吸附剂来处理有色废水，因为它成本低，几乎不需要加工，对阴离子和阳离子染料具有高吸附能力。