Shemy Marwa H, Mohamed Reham A, Abdel-Khalek Ahmed A, Alqhtani Haifa A, Al Zoubi Wail, Abukhadra Mostafa R
Department of Chemistry, Faculty of Science, Beni-Suef University, Beni-Suef City, Egypt.
Department of Biology, College of Science, Princess Nourah Bint Abdulrahman University, Riyadh, Saudi Arabia.
Front Chem. 2025 May 8;13:1583305. doi: 10.3389/fchem.2025.1583305. eCollection 2025.
The development of highly efficient, recyclable adsorbents for heavy metal remediation remains a critical challenge in environmental engineering. This study introduces a novel cetyltrimethylammonium bromide-functionalized magnesium silicate (CTAB/MS) nano-adsorbent was synthesized through a multi-step surface modification of serpentinite involving intercalation with dimethyl sulfoxide, methanol treatment, and CTAB incorporation. The resulting nanostructure was extensively characterized and applied for the removal of cadmium (Cd), cobalt (Co), and copper (Cu) ions from contaminated water. The characterization findings confirmed significant morphological and structural modifications, including enhanced surface area, functional group availability, and mesoporosity, which contributed to enhanced adsorption performance. The kinetic modeling confirmed that the process predominantly followed a pseudo-first-order model, suggesting that rapid physisorption mechanisms controlled the initial adsorption phase. Equilibrium studies revealed that adsorption followed the Langmuir isotherm model, indicating monolayer adsorption on homogeneous active sites, with maximum adsorption capacities of 491.9 mg/g (Cd), 481.8 mg/g (Co), and 434.3 mg/g (Cu) at 303 K. Furthermore, statistical physics-based isotherm model incorporating steric and energetic parameters provided deeper mechanistic insights. The adsorption energy (ΔE) values remained below 12.66 kJ/mol, confirming a predominantly physical adsorption process, while thermodynamic analysis indicated an exothermic and spontaneous nature, as evidenced by negative free enthalpy (G) and internal energy (E) values. The recyclability assessment demonstrated that CTAB/MS retained over 70% of its adsorption efficiency after five consecutive regeneration cycles, underscoring its long-term applicability in water treatment. This highlights the potential of CTAB/MS as an advanced, cost-effective, and sustainable solution for large-scale water purification.
开发用于重金属修复的高效、可回收吸附剂仍然是环境工程中的一项关键挑战。本研究介绍了一种新型十六烷基三甲基溴化铵功能化硅酸镁（CTAB/MS）纳米吸附剂，它是通过对蛇纹石进行多步表面改性合成的，包括用二甲基亚砜插层、甲醇处理和引入CTAB。对所得纳米结构进行了广泛表征，并将其用于去除受污染水中的镉（Cd）、钴（Co）和铜（Cu）离子。表征结果证实了显著的形态和结构变化，包括比表面积增加、官能团可用性提高和介孔率增加，这些都有助于提高吸附性能。动力学模型证实，该过程主要遵循伪一级模型，这表明快速的物理吸附机制控制了初始吸附阶段。平衡研究表明，吸附遵循Langmuir等温模型，表明在均匀活性位点上的单层吸附，在303K时，对Cd、Co和Cu的最大吸附容量分别为491.9mg/g、481.8mg/g和434.3mg/g。此外，结合空间位阻和能量参数的基于统计物理的等温模型提供了更深入的机理见解。吸附能（ΔE）值保持在12.66kJ/mol以下，证实了主要是物理吸附过程，而热力学分析表明该过程是放热和自发的，自由焓（G）和内能（E）值为负证明了这一点。可回收性评估表明，CTAB/MS在连续五次再生循环后仍保留其吸附效率的70%以上，突出了其在水处理中的长期适用性。这凸显了CTAB/MS作为大规模水净化的先进、经济高效且可持续解决方案的潜力。
