This research work is based on the isolation of cellulosic fibers from Tunisian olive sawdust (TOS) by alkaline treatment using a solution of NaOH at different concentrations: 5% w/v (TOS5) and 20% w/v (TOS20). The valorization of these cellulosic supports was assessed by the adsorption ability of methylene blue (MB), chosen as a model compound of organic dyes. SEM and FTIR analyses have shown that alkaline treatment produces a delignification of TOS and an elimination of hemicellulose. A transformation of cellulose I to cellulose II was shown by XRD following the decrease of the crystallinity indices passing from TOS5 (∼37%) to TOS20 (∼30%). The spectroscopic study confirmed that the intermolecular and intramolecular hydrogen bonds have a primordial role in the forms and the structural stability of the cellulosic substrates. Thereby, the deconvolution of OH stretching vibration band confirmed the transition from cellulose I to cellulose II by the occurrence of a new band at 3,080 cm⁻¹ for TOS20. The increase of iodine adsorption values (ISV) from 40 mg·g⁻¹ for TOS5 to 65mg·g⁻¹ for TOS20 is behind the improvement of the accessibility of cellulosic support with alkaline treatment of TOS. The adsorption of MB onto the surface of cellulosic substrates in aqueous mixtures was studied quantitatively. The corresponding isotherms in basic medium have shown the formation of a monolayer following the Langmuir model characterized by 14 mg·g⁻¹, 52 mg·g⁻¹ and 76 mg·g⁻¹ onto the TOS, TOS5 and TOS20, respectively. The desorption efficiency of MB in acid medium increased with 37%, 57% and 71% for TOS, TOS5 and TOS20, respectively. Hence, the extracted cellulosic fibers are likely to be a promising adsorbent for the removal of organic dye from aqueous solutions.

这项研究工作基于使用不同浓度的 NaOH 溶液碱处理从突尼斯橄榄锯末 (TOS) 中分离纤维素纤维：5% w/v (TOS5) 和 20% w/v (TOS20)。通过选择作为有机染料模型化合物的亚甲蓝 (MB) 的吸附能力来评估这些纤维素载体的价值。SEM 和 FTIR 分析表明，碱处理使 TOS 脱木素和消除半纤维素。在结晶度指数从 TOS5 (~37%) 降低到 TOS20 (~30%) 之后，通过 XRD 显示纤维素 I 向纤维素 II 的转变。光谱研究证实，分子间和分子内氢键对纤维素底物的形态和结构稳定性具有重要作用。从而，^-1对于 TOS20。碘吸附值 (ISV) 从TOS5 的40 mg·g ^-1增加到 TOS20 的 65mg·g ^-1是通过 TOS 的碱处理改善纤维素载体的可及性的背后。定量研究了 MB 在水性混合物中纤维素基质表面的吸附。基本介质中的相应等温线显示了遵循以 14 mg·g ^-1、52 mg·g ^-1和 76 mg·g ^{-1 为}特征的 Langmuir 模型形成的单层分别在 TOS、TOS5 和 TOS20 上。对于TOS、TOS5和TOS20，MB在酸性介质中的解吸效率分别提高了37%、57%和71%。因此，提取的纤维素纤维可能是一种有前途的吸附剂，可用于从水溶液中去除有机染料。