Key Laboratory of Wood Material Science and Utilization (Beijing Forestry University), Ministry of Education, Beijing 100083, PR China.
Key Laboratory of Wood Material Science and Utilization (Beijing Forestry University), Ministry of Education, Beijing 100083, PR China.
J Hazard Mater. 2021 Aug 15;416:125896. doi: 10.1016/j.jhazmat.2021.125896. Epub 2021 Apr 20.
Cork, a porous biomass material, is consist of thin-walled hollow prismatic cells arranged into a compact and orderly honeycomb-like structure and could be applied as an adsorption material. Here, cork-activated carbons (CACs) with a fluffy honeycomb-like structure were synthesized by two-step pyrolysis with solid KOH chemical activation to rapidly and efficiently adsorb methylene blue (MB) (maximum wavelength: 664 nm). The structure, morphology and surface functional groups of the CACs were characterized using BET, SEM, and FTIR analysis. The results show that the CACs have a well-developed hierarchical porous structure and an ultra-high specific surface area of 2864.9 m/g, which would facilitate the efficient diffusion and adsorption of MB molecules onto CACs. MB adsorption performance results show that the CACs have an outstanding maximum MB adsorption capacity (1103.68 mg/g) and fast adsorption kinetics (800 mg/L, 99.8% in 10 min), indicating that CACs possess significant advantages compared with most other adsorbents previously reported. The adsorption mechanism was studied by various kinetic models, isothermal models and thermodynamic models. Langmuir model is the most adapted to describe the adsorption process, indicating that the MB molecules are uniformly adsorbed on CAC's surface in a single layer. Moreover, MB adsorption by the CACs was an endothermic, spontaneous and randomly increasing adsorption. The regeneration test showed that the uptake of MB onto CACs can still reached 580 mg/g after three adsorption-desorption cycles, demonstrating the excellent reusability of CACs. The continuous adsorption performance of MB onto CACs was evaluated by a packed column test, which further confirmed its potential as an adsorbent for dye wastewater purification.
软木，一种由薄壁中空棱柱细胞组成的多孔生物质材料，排列成紧密有序的蜂窝状结构，可用作吸附材料。在这里，通过两步热解与固体 KOH 化学活化相结合，合成了具有蓬松蜂窝状结构的软木活性炭（CACs），可快速高效地吸附亚甲基蓝（MB）（最大波长：664nm）。通过 BET、SEM 和 FTIR 分析对 CACs 的结构、形貌和表面官能团进行了表征。结果表明，CACs 具有发达的分级多孔结构和超高的比表面积（2864.9 m/g），这有利于 MB 分子在 CACs 上的有效扩散和吸附。MB 吸附性能结果表明，CACs 具有出色的最大 MB 吸附容量（1103.68mg/g）和快速吸附动力学（800mg/L，10min 内达到 99.8%），表明 CACs 与之前报道的大多数其他吸附剂相比具有显著优势。通过各种动力学模型、等温模型和热力学模型研究了吸附机理。Langmuir 模型最适合描述吸附过程，表明 MB 分子在 CAC 的表面上以单层均匀吸附。此外，CACs 对 MB 的吸附是吸热、自发和随机增加的吸附。再生试验表明，CACs 对 MB 的三次吸附-解吸循环后仍可达到 580mg/g 的吸附量，证明了 CACs 的优异可重复使用性。通过填充柱试验评价了 MB 在 CACs 上的连续吸附性能，进一步证实了其作为染料废水净化吸附剂的潜力。
