Zhang Shenghao, Li Mingyang, Zhang Hao, Fan Fuqiang, Zhou Chunyang, Lao Kangwen, Gao Xiangpeng
Key Laboratory of Mine Low-Carbon Reclamation and Solid Waste Resource Utilization of Ma'anshan, Anhui University of Technology, Ma'anshan, Anhui 243032, China; Advanced Institute of Natural Sciences, Beijing Normal University at Zhuhai, Zhuhai, Guangdong 519087, China.
Key Laboratory of Mine Low-Carbon Reclamation and Solid Waste Resource Utilization of Ma'anshan, Anhui University of Technology, Ma'anshan, Anhui 243032, China.
Int J Biol Macromol. 2024 Nov;280(Pt 4):136117. doi: 10.1016/j.ijbiomac.2024.136117. Epub 2024 Sep 27.
The excessive amounts of phosphorus (P) discharged and usage have caused eutrophication and algal blooms, which seriously jeopardize the environment even the human health. In this study, carbon nanotubes (CNTs) served as carriers to develop a lanthanum-based sodium alginate hydrogel (La-CNT-COOH/SA) aimed at efficiently removing phosphate from wastewater. Characterization results confirmed successful deposition of La(OH) nanoparticles onto CNT-COOH. The optimal adsorption efficiency of La-CNT-COOH/SA hydrogels occurred at pH 4, with a maximum adsorption capacity of 54.4 mg/g under an initial phosphate concentration of 60 mg/L. Batch experiments demonstrated that La-CNT-COOH/SA performed well across a favorable pH range and exhibited high tolerance to common coexisting ions during phosphate adsorption. Adsorption isotherms indicated a dominance of both physical and chemical mechanisms in phosphate removal by La-CNT-COOH/SA. At elevated phosphate concentrations, the adsorption process followed quasi-second-order kinetics, primarily driven by chemical adsorption. Multi-instrument characterization emphasized that the substantial loading of La(OH) on CNT-COOH significantly contributed to adsorption, alongside crosslinked lanthanum ions on sodium alginate and abundant hydroxyl groups. Mechanisms of adsorption by La-CNT-COOH/SA encompassed electrostatic interactions, surface precipitation, and in-sphere complexation (La-O-P). These findings on fabrication, properties, and adsorption mechanisms of the phosphate-removal hydrogel lay a theoretical foundation for applying biomass-based materials in large-scale remediation practices.
过量排放和使用的磷（P）已导致富营养化和藻华，严重危害环境甚至人类健康。在本研究中，碳纳米管（CNTs）作为载体，开发了一种基于镧的海藻酸钠水凝胶（La-CNT-COOH/SA），旨在有效去除废水中的磷酸盐。表征结果证实La(OH)纳米颗粒成功沉积在CNT-COOH上。La-CNT-COOH/SA水凝胶在pH为4时吸附效率最佳，在初始磷酸盐浓度为60mg/L时最大吸附容量为54.4mg/g。批次实验表明，La-CNT-COOH/SA在适宜的pH范围内表现良好，在磷酸盐吸附过程中对常见共存离子具有高耐受性。吸附等温线表明，La-CNT-COOH/SA去除磷酸盐的过程中物理和化学机制均占主导地位。在较高的磷酸盐浓度下，吸附过程遵循准二级动力学，主要由化学吸附驱动。多仪器表征强调，La(OH)在CNT-COOH上的大量负载对吸附有显著贡献，同时海藻酸钠上的交联镧离子和丰富的羟基也有贡献。La-CNT-COOH/SA的吸附机制包括静电相互作用、表面沉淀和球内络合（La-O-P）。这些关于除磷水凝胶的制备、性能和吸附机制的研究结果为将生物质基材料应用于大规模修复实践奠定了理论基础。
