Shaanxi University of Science & Technology, Xi'an, 710021, China.
Shaanxi Research Institute of Agricultural Products Processing Technology, Xi'an, 710021, China.
Environ Sci Pollut Res Int. 2024 Apr;31(16):24220-24234. doi: 10.1007/s11356-024-32652-z. Epub 2024 Mar 4.
Two natural adsorbent materials, potassium humate (KHA) and montmorillonite (MMT), were successfully prepared by embedding them in sodium alginate (SA) gel spheres through physical cross-linking with CaCl. And CaCO was used as a porogenic agent to prepare the porous composites, KHA/SA/MMT. The materials were characterized by using XRD, TGA, SEM, and N adsorption/desorption equipment. The results showed that MMT and KHA were successfully embedded in the SA gel; the introduction of MMT increased the thermal stability of the composites and the embedding of MMT, and the porogenic effect of CaCO increased the specific surface area of the composites substantially, which provided favorable conditions for adsorption and treatment of pollutants. In addition, a one-way exploratory experiment yielded a higher removal rate of Rhodamine B (RhB) at D = 0.6 g/L, pH = 5, C = 100 mg/L, and t = 360 min. The adsorption kinetics and adsorption isotherm conformed to the secondary kinetic model and Langmuir model, respectively, and the maximum adsorption of RhB by KHA/SA/MMT could reach up to 884.96 mg/g at 303 K. The adsorption mechanism for RhB was shown by FT-IR and XPS analyses to be possibly bound by non-covalent bonding forces. After seven consecutive adsorption-desorption cycles, the adsorption of RhB by KHA/SA/MMT still reached 80.75%. Therefore, the prepared gel spheres have the advantages of easy regeneration and efficient reuse and great potential for application in purifying RhB from wastewater.
两种天然吸附材料——腐植酸钾（KHA）和蒙脱石（MMT），通过与 CaCl2 进行物理交联成功嵌入到海藻酸钠（SA）凝胶球中。然后使用 CaCO3 作为造孔剂制备多孔复合材料 KHA/SA/MMT。采用 XRD、TGA、SEM 和 N2 吸附/脱附设备对材料进行了表征。结果表明，MMT 和 KHA 成功嵌入到 SA 凝胶中；MMT 的引入提高了复合材料的热稳定性，同时 CaCO3 的造孔效应极大地提高了复合材料的比表面积，为吸附和处理污染物提供了有利条件。此外，在 D=0.6 g/L、pH=5、C=100 mg/L、t=360 min 的条件下，进行单向探索性实验，得到了 Rhodamine B（RhB）更高的去除率。吸附动力学和吸附等温线分别符合二级动力学模型和 Langmuir 模型，KHA/SA/MMT 对 RhB 的最大吸附量在 303 K 时可达 884.96 mg/g。通过 FT-IR 和 XPS 分析表明，RhB 的吸附机理可能是通过非共价键力结合的。经过七次连续的吸附-解吸循环后，KHA/SA/MMT 对 RhB 的吸附仍可达 80.75%。因此，所制备的凝胶球具有易于再生和高效重复使用的优点，在从废水中净化 RhB 方面具有很大的应用潜力。
