Simultaneous removal of dyes in the effluents of printing and dyeing industries is challenging, and the mechanism of the co-adsorption of dyes is still unclear. In this context, a novel adsorbent based on microcrystalline cellulose from cotton fiber through a simplified chemical modification process was prepared. Methylene blue (MB) and neutral red (NR) were selected to investigate their adsorption/co-adsorption on such functionalized microcrystalline cellulose. The experimental adsorption results indicated that the adsorption quantity of both dyes was similar for the single solute. The kinetics of adsorption processes could be better described with the pseudo-second order models for both single and binary dye solutes. The results of the co-adsorption suggested that the extended Langmuir model could well predict equilibrium. The maximum adsorption capacity of MB and NR for the single systems was 115.2 and 83.2 mg/g, respectively. Moreover, an antagonistic effect could be found in the binary dye solute. The obtained results revealed that the co-adsorption of dyes might be driven by hydrogen bonding, π-π stacking interaction as well as electrostatic interaction.

中文翻译：

---

使用棉纤维功能化微晶纤维素从水溶液中单一和二元吸附染料

同时去除印染工业废水中的染料具有挑战性，染料共吸附的机理尚不清楚。在此背景下，通过简化的化学改性工艺制备了一种基于来自棉纤维的微晶纤维素的新型吸附剂。选择亚甲蓝 (MB) 和中性红 (NR) 来研究它们在这种功能化微晶纤维素上的吸附/共吸附。实验吸附结果表明，两种染料对单一溶质的吸附量相似。吸附过程的动力学可以用单一和二元染料溶质的伪二级模型更好地描述。共吸附的结果表明扩展的朗缪尔模型可以很好地预测平衡。MB 和 NR 对单一系统的最大吸附容量分别为 115.2 和 83.2 mg/g。此外，在二元染料溶质中可以发现拮抗作用。结果表明，染料的共吸附可能是由氢键、π-π堆积相互作用以及静电相互作用驱动的。