CAS Key Laboratory of Mineralogy and Metallogeny, Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China; School of Chemical Engineering and Advanced Materials, The University of Adelaide, Adelaide, South Australia 5005, Australia.
Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Provincial Key Laboratory of Geology and Environment of Salt Lakes, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008, China.
Sci Total Environ. 2024 Nov 15;951:175641. doi: 10.1016/j.scitotenv.2024.175641. Epub 2024 Aug 20.
The extensive use of the antibiotic oxytetracycline (OTC) has led to considerable environmental contamination and other negative impacts, prompting an urgent need for a green, effective, and innovative OTC adsorption material. In this study, diatom-allophane bio-nanocomposites were synthesized using a simple and eco-friendly method, yielding a homogeneous coating of allophane nanoparticles on diatom surfaces. The resultant bio-nanocomposites were found to have hierarchically porous structures and abundant active sites derived from successful allophane loading and dispersion on diatom surfaces. The OTC adsorption capacity of this novel adsorbent is remarkable (219.112 mg·g), surpassing the capacities of raw allophane and diatoms by >5 and 10 times, respectively. Mechanistically, OTC adsorption by the bio-nanocomposites was found to be driven primarily by chemisorption through a process involving complexation between the amide and amino groups on OTC and the aluminum hydroxyl and carboxyl groups on the adsorbent surface. Electrostatic interactions and hydrogen bonding also contribute significantly to OTC capture. Furthermore, the diatom-allophane bio-nanocomposites exhibit excellent performance over a wide pH range (4-7), in the presence of various cations (Na, K, Ca, Mg) and anions (Cl, NO, SO), and in real water bodies. These findings demonstrate the potential of the diatom-allophane bio-nanocomposite as a green, efficient, and promising biological-mineral adsorbent for environmental remediation, leveraging the combined utilization of biological and mineral resources.
抗生素土霉素（OTC）的广泛使用导致了相当大的环境污染和其他负面影响，因此迫切需要一种绿色、有效和创新的 OTC 吸附材料。在本研究中，使用简单且环保的方法合成了硅藻-埃洛石生物纳米复合材料，在硅藻表面均匀涂覆了埃洛石纳米颗粒。结果表明，所得生物纳米复合材料具有分级多孔结构和丰富的活性位点，这是由于埃洛石在硅藻表面的成功负载和分散。这种新型吸附剂对 OTC 的吸附容量非常高（219.112mg·g），分别比原始埃洛石和硅藻的吸附容量高出>5 倍和 10 倍。从机理上看，生物纳米复合材料对 OTC 的吸附主要是通过化学吸附驱动的，涉及 OTC 上的酰胺和氨基与吸附剂表面上的铝羟基和羧基之间的络合。静电相互作用和氢键也对 OTC 的捕获有很大贡献。此外，硅藻-埃洛石生物纳米复合材料在很宽的 pH 值范围（4-7）内、存在各种阳离子（Na、K、Ca、Mg）和阴离子（Cl、NO、SO）以及实际水体中均表现出优异的性能。这些发现表明，硅藻-埃洛石生物纳米复合材料作为一种绿色、高效和有前途的生物-矿物吸附剂，具有用于环境修复的潜力，利用了生物和矿物资源的综合利用。
