Juturu Rajesh, Vinayagam Ramesh, Murugesan Gokulakrishnan, Selvaraj Raja
Department of Biotechnology, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India.
Department of Chemical Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India.
Sci Rep. 2025 Apr 12;15(1):12670. doi: 10.1038/s41598-025-96439-z.
This study evaluates mesoporous-hydrochar derived from Acacia falcata leaves via a single-step hydrothermal treatment for Cr(VI) adsorption. Material characterization indicated that the adsorbent has a rough and porous structure. FTIR analysis confirmed Cr(VI) adsorption through functional group interactions, evidenced by peak intensity changes and the emergence of a Cr-O bond vibration at 669 cm. Two new peaks were observed in XPS spectra, corresponding to Cr 2p at 577.04 eV (Cr 2p3/2) and 586.67 eV (Cr 2p1/2) after adsorption, further substantiating the adsorption and Cr(VI) reduction. Batch experiments showed an improved adsorption capacity of 30.47 mg/g. Kinetic investigation adhered to the pseudo-second-order model, whereas the equilibrium dataset satisfied the Freundlich model, indicating a heterogeneous adsorption mechanism involving physisorption and chemisorption. The thermodynamic evaluation confirmed spontaneous and endothermic adsorption. Regeneration studies showed reduced Cr(VI) removal performance after four cycles, attributed to pore blockage and loss of functional groups while maintaining effective reuse potential. Spiked studies in various water matrices showed a slight decrease in Cr(VI) removal efficiency, yet it maintained over 95% efficiency, demonstrating its potential for real-world water treatment applications.
本研究评估了通过一步水热处理从镰叶相思树叶中获得的介孔水炭对六价铬（Cr(VI)）的吸附性能。材料表征表明，吸附剂具有粗糙的多孔结构。傅里叶变换红外光谱（FTIR）分析证实了通过官能团相互作用实现Cr(VI)吸附，这通过峰强度变化以及在669 cm处出现Cr-O键振动得以证明。X射线光电子能谱（XPS）光谱中观察到两个新峰，分别对应吸附后577.04 eV（Cr 2p3/2）和586.67 eV（Cr 2p1/2）处的Cr 2p，进一步证实了吸附和Cr(VI)的还原。批量实验表明吸附容量提高到30.47 mg/g。动力学研究符合准二级模型，而平衡数据集符合弗伦德利希模型，表明存在涉及物理吸附和化学吸附的非均相吸附机制。热力学评估证实吸附是自发且吸热的。再生研究表明，四个循环后Cr(VI)去除性能下降，这归因于孔堵塞和官能团损失，不过仍保持有效的重复利用潜力。在各种水基质中的加标研究表明Cr(VI)去除效率略有下降，但仍保持在95%以上，证明了其在实际水处理应用中的潜力。
