Zhang Shenghao, Yuan Xingyu, Li Mingtao, Gong Kaiyuan, Zhou Chunyang, Gao Xiangpeng, Li Mingyang, Fan Fuqiang
Guangdong-Hong Kong Joint Laboratory for Water Security, Beijing Normal University, Zhuhai 519087, China; Center for Water Research, Advanced Institute of Natural Sciences, Beijing Normal University, Zhuhai 519087, China; School of Metallurgical Engineering, Anhui University of Technology, Maanshan 243032, Anhui, China.
Guangdong-Hong Kong Joint Laboratory for Water Security, Beijing Normal University, Zhuhai 519087, China; Center for Water Research, Advanced Institute of Natural Sciences, Beijing Normal University, Zhuhai 519087, China.
Int J Biol Macromol. 2025 Feb;290:138918. doi: 10.1016/j.ijbiomac.2024.138918. Epub 2024 Dec 17.
Challenges in developing adsorbents with sufficient phosphate (P) adsorption capacity, selectivity, and regeneration properties remain to be addressed. Herein, a multi-functionalized high-capacity nanocellulose/alginate hydrogel (La-NCF/SA-PEI [La: lanthanum, NCF: nanocellulose fiber, SA: sodium alginate, PEI: polyethyleneimine]) was prepared through environmentally friendly methods. The La-NCF/SA-PEI hydrogel, featuring a 3D porous structure with interwoven functional groups (amino, quaternary ammonium, and lanthanum), demonstrated a maximum P adsorption capacity of 78.0 mg/g, exceeding most La-based hydrogel adsorbents. The kinetic and isotherm fitting results confirmed the multilayer chemisorption process. Comprehensive experimental results, instrumental analysis, and computational results revealed that the ammonium phosphate complex (NH-O-P) and the inner-sphere complex (La-O-P) formed by La(OH) dominated the selective P adsorption process. Density-functional theory (DFT) was employed to calculate the bond length between phosphate and each component of the La-NCF/SA-PEI. The calculation results revealed the double-bridge adsorption between the N (apex) atom on La-NCF/SA-PEI and the O (apex) atomic site in phosphate, including electrostatic adsorption and two hydrogen bonds (bond lengths 1.001 and 1.008 Å) between the O of PO and the H of the protonated amino group. Except the remarkable P adsorption performance (both municipal sewage and aquaculture tail water), the La-NCF/SA-PEI hydrogel's high selectivity toward P, environmental compatibility, and easy separability from water underscore its significant potential for phosphate-contaminated water remediation. The multi-functionalized La-NCF/SA-PEI demonstrate promising potential for P removal applications and advanced the development of sustainable, biomass-based adsorbents design.
开发具有足够磷（P）吸附容量、选择性和再生性能的吸附剂仍面临挑战。在此，通过环保方法制备了一种多功能高容量纳米纤维素/海藻酸盐水凝胶（La-NCF/SA-PEI [La：镧，NCF：纳米纤维素纤维，SA：海藻酸钠，PEI：聚乙烯亚胺]）。La-NCF/SA-PEI水凝胶具有三维多孔结构，带有相互交织的官能团（氨基、季铵基和镧），其最大P吸附容量为78.0 mg/g，超过了大多数基于镧的水凝胶吸附剂。动力学和等温线拟合结果证实了多层化学吸附过程。综合实验结果、仪器分析和计算结果表明，由La(OH)形成的磷酸铵络合物（NH-O-P）和内球络合物（La-O-P）主导了选择性P吸附过程。采用密度泛函理论（DFT）计算了磷酸盐与La-NCF/SA-PEI各组分之间的键长。计算结果揭示了La-NCF/SA-PEI上的N（顶点）原子与磷酸盐中的O（顶点）原子位点之间的双桥吸附，包括静电吸附以及PO的O与质子化氨基的H之间的两个氢键（键长分别为1.001和1.008 Å）。除了显著的P吸附性能（对城市污水和水产养殖尾水均有效）外，La-NCF/SA-PEI水凝胶对P的高选择性、环境相容性以及易于从水中分离的特性突出了其在修复含磷污染水方面的巨大潜力。多功能化的La-NCF/SA-PEI在P去除应用中显示出广阔的前景，并推动了可持续的、基于生物质的吸附剂设计的发展。
