Al Ghamdi Khalid, Ahmad Aqeel, Falca Gheorghe, Alrefaeia Meshal Nawaf, Al-Hamouz Othman Charles S
Department of Chemistry, King Fahd University of Petroleum and Minerals (KFUPM), Dhahran 31261, Saudi Arabia.
Interdisciplinary Research Center for Refining and Advanced Chemicals, King Fahd University of Petroleum and Minerals (KFUPM), Dhahran 31261, Saudi Arabia.
Polymers (Basel). 2024 Aug 31;16(17):2495. doi: 10.3390/polym16172495.
Mercury, a highly toxic metal and pollutant, poses a significant risk to human health and the environment. This study describes the synthesis of a new nitrogen-doped heteroaromatic hyper-crosslinked polyamine () via the polycondensation of 2,6-diaminopyrazine and tris(4-formylphenyl)amine for the efficient removal of mercury ions from aqueous solutions. The polymer was characterized by solid-state C-NMR and FT-IR spectroscopy. A powder X-ray diffraction and thermogravimetric analysis showed that the polymer was semicrystalline in nature and stable up to 500 °C. Adsorption isotherms indicated that mercury adsorption occurred via mono- and multilayer adsorption by , as depicted by the Langmuir, Freundlich, and Redlich-Peterson isotherm models, with a maximum adsorption capacity of = 333.3 mg/g. Adsorption kinetic models suggested that the adsorption process was fast and effective, reaching equilibrium within 20 min. Thermodynamics of the adsorption process revealed that it was endothermic and spontaneous in nature due to the positive Δ of 48 kJ/mol and negative Δ values of -4.5 kJ/mol at 293 K. Wastewater treatment revealed 98% removal of mercury indicating the selective nature of . Finally, exhibited excellent performance and regeneration up to three cycles, demonstrating its great potential as an adsorbent for environmental remediation applications.
汞是一种剧毒金属和污染物，对人类健康和环境构成重大风险。本研究描述了通过2,6 - 二氨基吡嗪和三（4 - 甲酰基苯基）胺的缩聚反应合成一种新型氮掺杂杂芳族超交联多胺（），用于从水溶液中高效去除汞离子。通过固态碳氮核磁共振和傅里叶变换红外光谱对该聚合物进行了表征。粉末X射线衍射和热重分析表明该聚合物本质上是半结晶的，在高达500°C时稳定。吸附等温线表明汞的吸附是通过该聚合物的单层和多层吸附发生的，如朗缪尔、弗伦德利希和雷德利希 - 彼得森等温线模型所描述，最大吸附容量为 = 333.3 mg/g。吸附动力学模型表明吸附过程快速有效，在20分钟内达到平衡。吸附过程的热力学表明，由于在293 K时48 kJ/mol的正Δ和 - 4.5 kJ/mol的负Δ值，该过程是吸热且自发的。废水处理显示汞的去除率为98%，表明该聚合物具有选择性。最后，该聚合物表现出优异的性能和高达三个循环的再生能力，证明了其作为环境修复应用吸附剂的巨大潜力。
