Institute of Highland Forest Science, Chinese Academy of Forestry. Research Center of Engineering and Technology of Characteristic Forest Resources, Key Laboratory of Breeding and Utilization of Resource Insects, National Forestry and Grassland Administration, Kunming, 650223, China; Nanjing Forestry University, Nanjing, 210037, China.
College of Forestry, Southwest Forestry University, Kunming, 650224, China.
Environ Res. 2024 Jul 1;252(Pt 1):118252. doi: 10.1016/j.envres.2024.118252. Epub 2024 Feb 5.
To effectively remove tannic acid (TA) from wastewater, using green and natural materials has attracted increasing attention. Inspired by Galla Chinensis (GC) with high content of TA, this study synthesized a biomimetic porous adsorbent to mimic the GC structure using dialdehyde tapioca starch (DTS) and gelatin (GL). The TA adsorption performance and mechanism of synthetic porous material were investigated. Results revealed that the porous material exhibited a maximum TA adsorption capacity of 1072.01 mg/g, along with a high removal rate of 95.16% under the conditions of a DTS-GL mass ratio of 1:1, DTS aldehyde content of 48.16%, a solid content of 5%, and a pH of 2 at 25 °C. The adsorption of TA by DTS was not affected by water-soluble cationic and anion. The adsorption kinetics of TA on the porous material followed the pseudo-second-order model, and this Langmuir adsorption model (R = 0.9954) which were well described the adsorption of TA by the material, indicating that the adsorption primarily occurred in a monolayer. FTIR, XRD, DSC, TG, XPS, and SEM-EDS were employed to characterize the structure characteristics of the porous material. The cross-linking between DTS and GL by Schiff base reaction imparted a chemical structure could absorb TA by hydrogen bonding. The TA desorption rates of in 30% acetone and 40% ethanol solutions were 88.76% and 91.03%, respectively. The porous material prepared by the GC-inspired approach holds promise as an ideal choice for loading polyphenolic compounds and provides a new perspective for the design and application of bioinspired engineering materials.
为了有效去除废水中的单宁酸（TA），使用绿色环保、天然的材料引起了广泛关注。本研究受单宁酸含量较高的五倍子启发，采用双醛淀粉（DTS）和明胶（GL）合成了一种仿生多孔吸附剂来模拟五倍子结构，研究了合成多孔材料的 TA 吸附性能和吸附机制。结果表明，在 DTS-GL 质量比为 1:1、DTS 醛基含量为 48.16%、固含量为 5%、pH 值为 2 的条件下，该多孔材料对 TA 的最大吸附量为 1072.01mg/g，去除率高达 95.16%。DTS 对 TA 的吸附不受水溶性阳离子和阴离子的影响。多孔材料对 TA 的吸附动力学符合准二级动力学模型，Langmuir 吸附模型（R2=0.9954）能较好地描述 TA 在多孔材料上的吸附过程，表明吸附主要发生在单层。采用傅里叶变换红外光谱（FTIR）、X 射线衍射（XRD）、差示扫描量热法（DSC）、热重分析（TG）、X 射线光电子能谱（XPS）和扫描电子显微镜-能谱仪（SEM-EDS）对多孔材料的结构特征进行了表征。DTS 和 GL 之间通过席夫碱反应交联形成的化学结构可以通过氢键吸附 TA。多孔材料在 30%丙酮和 40%乙醇溶液中的解吸率分别为 88.76%和 91.03%。该方法制备的多孔材料有望成为负载多酚类化合物的理想选择，为仿生工程材料的设计和应用提供了新的视角。
