Liu Huijuan, Cheng Zhifei, Wu Xianliang, Xie Jiao
The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, Department of Nutrition and Food Hygiene, School of Public Health, Guizhou Medical University, Guiyang, 561113, Guizhou, China.
Basic Teaching Department, Guizhou Vocational College of Agriculture, Guizhou, 551400, China.
Sci Rep. 2025 Apr 24;15(1):14395. doi: 10.1038/s41598-025-99307-y.
Metformin, a typical pharmaceutical and personal care product (PPCPs), has a significant role in protecting brain cognitive function and delaying multiple organs aging, as well as causes seriously endocrine and reproductive interference to aquatic organisms due to drug abuse. Graphene that is of stable structure, flexible connection between carbon atoms, and the conjugated large pi bonds has been used to wastewater treatment, while Graphene-based materials used to remove PPCPs are rarely reported. Therefore, two graphene oxide (GO) based materials, including silane coupling agent modified product (CTOS-mGO) and Pyracantha fortuneana proanthocyanidin extract reduced product (PFPA-rGO), were used for metformin removal from aqueous solution as well as revealed the mechanism in this adsorption process. The results showed that metformin could be quickly and effectively removed by GO, CTOS-mGO and PFPA-rGO, of which the best material of adsorption effects was CTOS-mGO. The pseudo-second-order kinetic could effectively describe their adsorption process, and they achieved more than 80% removal rate within 15 to 20 min. Metformin adsorption by GO, CTOS-mGO and PFPA-rGO were all spontaneous and exothermic. CTOS-mGO was of the largest adsorption capacity and recycling utilization for metformin removal in comparison with GO and PFPA-rGO. The optimal adsorption temperature and pH for the GO and CTOS-mGO, PFPA-rGO adsorbents were 293 K and pH 6.0, 293 K and pH 7.0, 303 K and pH 6.0, respectively. Our results suggested that the aromatic rings and the abundant oxygen-containing functional groups distributed on the surface of the sheets endowed them with the characteristics of π-electron acceptors or donors, and metformin with dissociative properties could serve as a stabilizer for this π-π interaction. In addition, the electrostatic interaction between the positively charged metformin and the negatively charged GO and CTOS-mGO were also important contributors to the adsorption reaction. Our results emphasized that the GO based materials might be an effective method for alleviating metformin and other PPCPs pollution, which also provided a reference for environmental remediation of similar pollutants.
二甲双胍是一种典型的药品和个人护理产品（PPCPs），在保护大脑认知功能和延缓多器官衰老方面具有重要作用，但由于药物滥用，它会对水生生物造成严重的内分泌和生殖干扰。石墨烯具有稳定的结构、碳原子之间灵活的连接以及共轭大π键，已被用于废水处理，而用于去除PPCPs的石墨烯基材料鲜有报道。因此，本文使用了两种基于氧化石墨烯（GO）的材料，包括硅烷偶联剂改性产物（CTOS-mGO）和火棘原花青素提取物还原产物（PFPA-rGO），用于从水溶液中去除二甲双胍，并揭示了该吸附过程的机制。结果表明，GO、CTOS-mGO和PFPA-rGO能够快速有效地去除二甲双胍，其中吸附效果最佳的材料是CTOS-mGO。准二级动力学能够有效地描述它们的吸附过程，它们在15至20分钟内实现了80%以上的去除率。GO、CTOS-mGO和PFPA-rGO对二甲双胍的吸附均为自发且放热过程。与GO和PFPA-rGO相比，CTOS-mGO对二甲双胍的吸附容量最大且可循环利用。GO、CTOS-mGO和PFPA-rGO吸附剂的最佳吸附温度和pH分别为293K和pH 6.0、293K和pH 7.0、303K和pH 6.0。我们的结果表明，片层表面分布的芳香环和丰富的含氧官能团赋予了它们π电子受体或供体的特性，具有解离性质的二甲双胍可以作为这种π-π相互作用的稳定剂。此外，带正电荷的二甲双胍与带负电荷的GO和CTOS-mGO之间的静电相互作用也是吸附反应的重要贡献因素。我们的结果强调，基于GO的材料可能是减轻二甲双胍和其他PPCPs污染的有效方法，这也为类似污染物的环境修复提供了参考。
