The adsorption of methylene blue (MB) on graphene-based adsorbents was tested through the batch experimental method. Two types of graphene-based adsorbents as graphene oxide (GO) and reduced graphene oxide (RGO) were compared to investigate the best adsorbent for MB removal. So that optimizing the MB removal for the selected type of graphene-based adsorbent, the diverse experimental factors, as pH (2–10), contact time (0–1440 min), adsorbent dosage (0.5–2 g/L), and initial MB concentration (25–400 mg/L) were analyzed. The conclusions indicated that the MB removal rised with an increase in the initial concentration of the MB and so rises in the amount of adsorbent used and initial pH. Maximum dye removal was calculated as 99.11% at optimal conditions after 240 min. Adsorption data were compiled by the Langmuir isotherm (R²: 0.999) and pseudo-second-order kinetic models (R²: 0.999). The Langmuir isotherm model accepted that the homogeneous surface of the GO adsorbent covering with a single layer. And the adsorption energy was calculated as 9.38 kJ mol⁻¹ according to the D-R model indicating the chemical adsorption occurred. The results show that GO could be utilized for the treatment of dye-contaminated aqueous solutions effectively.

中文翻译：

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石墨烯基吸附剂在染料污染废水处理中的应用 动力学和等温线研究

通过批量实验方法测试亚甲基蓝（MB）在石墨烯基吸附剂上的吸附。比较了两种基于石墨烯的吸附剂，即氧化石墨烯 (GO) 和还原氧化石墨烯 (RGO)，以研究去除 MB 的最佳吸附剂。为了优化所选类型的石墨烯基吸附剂的 MB 去除，各种实验因素，如 pH (2-10)、接触时间 (0-1440 分钟)、吸附剂剂量 (0.5-2 g/L) 和分析了初始 MB 浓度 (25–400 mg/L)。结论表明，MB 去除率随着 MB 初始浓度的增加而增加，因此所用吸附剂的量和初始 pH 值也随之增加。在最佳条件下 240 分钟后，最大染料去除率计算为 99.11%。吸附数据由朗缪尔等温线 (R ²: 0.999) 和伪二级动力学模型 (R ² : 0.999)。Langmuir 等温线模型接受 GO 吸附剂的均匀表面覆盖有单层。根据表明发生化学吸附的 DR 模型，吸附能计算为 9.38 kJ mol ^-1。结果表明，GO可以有效地处理染料污染的水溶液。