Abstract In this paper, the wood powder from the shell of Argan nuts was used in raw form, or modified form by Sodium hydroxide, as a new economic and ecologic adsorbent. The effectiveness of these materials was evaluated on Methylene Blue (MB), a cationic dye. Those adsorbents were characterized by using scanning electron microscopy (SEM) and Fourier transformed infrared spectroscopy (FTIR). The effect of contact time (2-180 min), adsorbent dose (0.02- 0.8 g), initial dye concentration (50-500 mg/L), pH (2-10.5), and temperature (24-50°C) on the adsorption capacity was studied in a batch reactor. Result obtained showed that the process of MB adsorption onto both adsorbents is in good agreement with the Langmuir adsorption isotherm (R²=0.99 and qe, exp ≈ qe, cal=14.28 for ASN and 64.62 mg/g for ASNN) and followed the pseudo-second-order kinetic model (R²≈1 and qe, cal ≈ qe, exp). According to the equilibrium study, MB was better adsorbed on the modified powder (Qmax ≈ 70 mg/g) than on the raw powder (Qmax ≈ 14 mg/g). The thermodynamic study gives a negative enthalpy (- 28.70 for ASN and - 60.45 KJ/mol for ASNN), a negative Gibbs free energy (- 13.0 for ASN and -16.5 KJ/mol for ASNN), and negative entropy (- 53.14 for ASN and - 148.04 J/mol/K for ASNN) That confirms that the adsorption reaction is energetically favorable, exothermic and spontaneous. We propose an adsorption mechanism-based to electrostatic attractions and H- bonding interaction. The modified adsorbent was found to be comparable or better than others already studied materials, because of its high adsorption capacity and in only 10 minutes of agitation and its efficiency even after five utilizations.

中文翻译：

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用于吸附阳离子染料的来自刺阿干树的高效吸附剂：动力学、机理、等温线和热力学研究

摘要 本文以摩洛哥坚果壳中的木粉为原料，或用氢氧化钠改性，作为一种新型的经济生态吸附剂。这些材料的有效性在亚甲蓝 (MB)（一种阳离子染料）上进行了评估。这些吸附剂通过使用扫描电子显微镜 (SEM) 和傅里叶变换红外光谱 (FTIR) 进行表征。接触时间（2-180 分钟）、吸附剂剂量（0.02-0.8 克）、初始染料浓度（50-500 毫克/升）、pH（2-10.5）和温度（24-50°C）对在间歇反应器中研究吸附能力。获得的结果表明，MB 在两种吸附剂上的吸附过程与朗缪尔吸附等温线（R²=0.99 和 qe，exp ≈ qe，ASN 和 64 的 cal=14.28）非常吻合。ASNN 为 62 mg/g）并遵循伪二级动力学模型（R²≈1 和 qe，cal ≈ qe，exp）。根据平衡研究，MB 更好地吸附在改性粉末（Qmax ≈ 70 mg/g）上，而不是在原料粉末上（Qmax ≈ 14 mg/g）。热力学研究给出了负焓（对于 ASN 为 - 28.70，对于 ASNN 为 - 60.45 KJ/mol）、负吉布斯自由能（对于 ASN 为 - 13.0，对于 ASNN 为 -16.5 KJ/mol）和负熵（对于 ASN 为 - 53.14和 - 148.04 J/mol/K (ASNN) 这证实了吸附反应在能量上是有利的、放热的和自发的。我们提出了一种基于静电引力和氢键相互作用的吸附机制。发现改性吸附剂与其他已经研究过的材料相当或更好，