Khalid Khazzal Hummadi*, Sha Luo, Songbo He*

Chemosphere, 2022, 287: 131907

https://doi.org/10.1016/j.chemosphere.2021.131907

ABSTRACT: In this work, the inverse fluidized-bed bio-adsorption column is applied for the first time and is demonstrated using the torrefied rice husk (TRH) for the removal of methylene blue from the solution. The bio-adsorbents were characterized by BET, FI-IR, and SEM. The inverse fluidized-bed adsorption column using TRH becomes saturated in the 95-min continuous adsorption, during which the breakthrough time is 22 min, the overall MB removal (R) is 84%, and the adsorption capacity (Q_exp) on the TRH is 6.82 mg g⁻¹. These adsorption characteristics are superior to those in the fixed-bed adsorption column (R of 52% and Q_exp of 2.76 mg g⁻¹) at a lower flow rate (100 vs. 283 cm³ min⁻¹). Torrefaction of RH significantly increases the surface area (28 vs. 9 m² g−¹) and enhances the surface functional groups, leading to an improved maximum equilibrium adsorption amount from 21.5 to 38.0 mg g⁻¹ according to Langmuir model in the batch adsorption system. Besides, the increased Q_exp on the TRH is also obtained in the inverse fluidized-bed (5.25 vs. 2.77 mg g−1, 89% higher) and the fixed-bed (2.76 vs. 1.53 mg g⁻¹, 80% higher) adsorption columns compared to that on the RH.

摘要：本研究首次应用反向流化床生物吸附柱，以焙烧稻壳（TRH）为吸附剂去除溶液中的亚甲基蓝。通过BET、FI-IR和SEM对生物吸附剂进行了表征。在连续吸附95分钟内，使用TRH的反向流化床吸附柱达到饱和，其穿透时间为22分钟，总亚甲基蓝去除率（R）为84%，TRH的吸附容量（Q_exp）为6.82 mg g⁻¹。这些吸附特性优于在较低流速下运行的固定床吸附柱（R为52%，Q_exp为2.76 mg g⁻¹，流速分别为100 cm³ min⁻¹ 和283 cm³ min⁻¹）。稻壳的焙烧处理显著增加了其比表面积（从9 m² g⁻¹提高至28 m² g⁻¹）并增强了表面官能团，根据间歇吸附体系的Langmuir模型，最大平衡吸附量从21.5 mg g⁻¹提高至38.0 mg g⁻¹。此外，与原始稻壳相比，TRH在反向流化床（5.25 vs. 2.77 mg g⁻¹，提高89%）和固定床（2.76 vs. 1.53 mg g⁻¹，提高80%）吸附柱中也表现出更高的Q_exp。