Abstract In this paper, a study on the removal of imitated polystyrene (PS) microplastics in water was carried out based on the adsorption capacity of three-dimensional reduced graphene oxide (3D RGO). Scanning electron microscopy and X-ray diffractometry characterization showed that the freeze-dried 3D RGO formed a distinct porous spatial structure. Different experimental parameters, such as pH, ion concentration (C0), contact time (t), and temperature (T), were studied to investigate the PS microplastic adsorption performance of 3D RGO. The adsorption mechanism was mainly attributed to the strong π–π interaction between the carbon ring of 3D RGO and the benzene ring of PS microplastics. Sorption kinetic and isothermal data were obtained by the well-fitted Langmuir adsorption isotherm model and pseudo-second-order kinetic model. Furthermore, the result of thermodynamic analysis showed that the adsorption of PS microplastics was a spontaneous endothermic process. Under the optimal conditions of pH = 6, C0 = 600 mg/L, t = 120 min, and T = 26 °C, the maximum adsorption capacity of the prepared 3D RGO on PS microplastics was 617.28 mg/g. Furthermore, this method exhibited good feasibility in tap water and lake water.

中文翻译：

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三维还原氧化石墨烯对聚苯乙烯微塑料的吸附研究

摘要本文基于三维还原氧化石墨烯（3D RGO）的吸附能力，开展了去除水中仿聚苯乙烯（PS）微塑料的研究。扫描电子显微镜和 X 射线衍射表征表明，冻干的 3D RGO 形成了独特的多孔空间结构。研究了不同的实验参数，如pH、离子浓度(C0)、接触时间(t)和温度(T)，以研究3D RGO对PS微塑料的吸附性能。吸附机制主要归因于3D RGO的碳环与PS微塑料的苯环之间强烈的π-π相互作用。通过拟合良好的Langmuir吸附等温线模型和准二级动力学模型获得吸附动力学和等温数据。此外，热力学分析结果表明，PS微塑料的吸附是自发吸热过程。在pH=6、C0=600mg/L、t=120min、T=26℃的最佳条件下，制备的3D RGO对PS微塑料的最大吸附容量为617.28mg/g。此外，该方法在自来水和湖水中表现出良好的可行性。