In this study, the removal of methylene blue dye (MB) from aqueous solution was examined using a novel green adsorbent to overcome the obstacles encountered in chemical methods. Ricinus communis (RC) aqueous seeds extract was herein used as a reducing and capping agent to synthesize a novel nano-zero-valent iron (RC-nZVI) for the adsorption of harmful MB. Structural and morphological characterization of the synthesized RC-nZVI were performed using several techniques, e.g., steady-state absorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and zeta potential. The maximum efficiency of the removal was 96.8% at pH 6 and 25 °C. According to the kinetics study results, the adsorption process obeys the pseudo-first-order model. The experimental equilibrium data were fitted to the Freundlich isotherm model, the maximum adsorption capacity reached was 61.37 mg·g^–1, and the equilibrium parameters were determined. The synthesized RC-nZVI possesses good reusability and can be considered as a potential economic and environmentally friendly adsorbent.

中文翻译：

---

蓖麻籽提取物绿色合成纳米零价铁：表征及在亚甲基蓝污染水处理中的应用

在这项研究中，使用新型绿色吸附剂克服了化学方法中遇到的障碍，研究了从水溶液中去除亚甲蓝染料 (MB) 的过程。蓖麻(RC) 种子水提取物在本文中用作还原剂和封端剂，以合成用于吸附有害 MB 的新型纳米零价铁 (RC-nZVI)。使用多种技术对合成的 RC-nZVI 进行结构和形态表征，例如稳态吸收、扫描电子显微镜 (SEM)、透射电子显微镜 (TEM)、傅里叶变换红外 (FT-IR)、能量色散 X射线能谱 (EDS)、X 射线衍射 (XRD)、X 射线光电子能谱 (XPS) 和 zeta 电位。在 pH 6 和 25 °C 下，去除的最大效率为 96.8%。根据动力学研究结果，吸附过程服从准一级模型。实验平衡数据符合Freundlich等温线模型，达到的最大吸附量为61.37 mg·g^–1，并确定了平衡参数。合成的 RC-nZVI 具有良好的可重复使用性，被认为是一种潜在的经济和环境友好的吸附剂。