Pan Shu-Xin, Xie Ting-Zheng, Xiao Tang-Fu, Xie Jie-Hui
Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University Guangzhou 510006 China
School of Environmental Science and Engineering, Guangzhou University Guangzhou 510006 China.
RSC Adv. 2020 Dec 17;10(72):44470-44480. doi: 10.1039/d0ra09193f. eCollection 2020 Dec 9.
Thallium (Tl) is a highly toxic heavy metal, and its pollution and remediation in aquatic environments has attracted considerable attention. To reduce or remove Tl pollution in the environment, various strategies have been applied. Graphene oxide (GO) has abundant oxygen-containing functional groups, indicating its high application potential for pollution remediation methods involving binding to metal ions or positively charged organic molecules or electrostatic interaction and coordination. However, the adsorption of Tl to GO occurs physical adsorption, for which the adsorption efficiency is low. Therefore, herein, we report a new method to effectively remove Tl pollution in water. We combined GO with aza-crown ether, which enhanced the electronegativity and ability to bind metal ions. The functionalized graphene oxide (FGO) demonstrated high efficiency through a wide pH gradient of 5-10, with a dominant Tl(i) adsorption capacity (112.21 mg g) based on the Langmuir model (pH 9.0, adsorbent concentration of 0.8 g L). The adsorption of Tl(i) during removal fit a pseudo-second-order kinetic model well. The mechanisms of Tl removal involve physical and chemical adsorption. In summary, our study provides a new method for the detection and treatment of Tl-containing wastewater by using FGO.
铊（Tl）是一种剧毒重金属，其在水环境中的污染及修复问题已引起广泛关注。为减少或消除环境中的铊污染，人们已采用了各种策略。氧化石墨烯（GO）含有丰富的含氧官能团，这表明其在涉及与金属离子或带正电荷的有机分子结合、静电相互作用及配位作用的污染修复方法中具有很高的应用潜力。然而，铊在GO上的吸附属于物理吸附，吸附效率较低。因此，在此我们报道一种有效去除水中铊污染的新方法。我们将GO与氮杂冠醚相结合，这增强了其电负性及结合金属离子的能力。功能化氧化石墨烯（FGO）在5 - 10的宽pH梯度范围内表现出高效性，基于朗缪尔模型（pH 9.0，吸附剂浓度0.8 g/L），其对Tl(i)的主要吸附容量为112.21 mg/g。去除过程中Tl(i)的吸附很好地符合准二级动力学模型。铊的去除机制包括物理吸附和化学吸附。总之，我们的研究为利用FGO检测和处理含铊废水提供了一种新方法。
