The application of fiber adsorbents in water treatment has recently received major attention due to its cost-effectiveness, good recyclability, and easy separation. Herein, we developed a novel strategy to prepare quaternary ammonium salt functionalized polyacrylonitrile fibers with a polarity tunable surface micro-environment to enhance the removal of wastewater phosphate. For this purpose, quaternized fibers with hydrophilic hydroxyl (PAN_T-C2-OHF) and hydrophobic alkyl with different chain lengths (PAN_T-C2F, PAN_T-C4F, PAN_T-C6F, and PAN_T-C8F) were constructed and characterized. Results of the adsorption experiment revealed that PAN_T-C2-OHF containing hydrophilic hydroxyl groups had the best adsorption capacity for phosphate (24.44 mg g^-1) within the adsorption equilibrium of 5 min. Furthermore, PAN_T-C2-OHF could effectively remove wastewater phosphate in a wide pH range (3-9), even in the presence of Cl^-, CO₃^2-, NO₃^-, etc. The adsorption kinetics and isotherms of PAN_T-C2-OHF for phosphate were better described by the pseudo-second kinetics and Langmuir isotherm models, indicating a monolayer chemical adsorption process. Besides, PAN_T-C2-OHF possessed excellent recyclability of at least 10 times and an extremely low adsorption limit for phosphate (0.02 mg P L^-1) in actual wastewater. In brief, this study provides proof for PAN_T-C2-OHF as a new environmental adsorbent with high efficiency, selectivity, and reusability for removal and recovery of phosphate.

纤维吸附剂在水处理中的应用最近因其成本效益，良好的可回收性和易于分离而受到了广泛的关注。在这里，我们开发了一种新的策略来制备季铵盐官能化的聚丙烯腈纤维，该纤维具有极性可调的表面微环境，以增强废水磷酸盐的去除。为此，具有亲水性羟基（PAN _T-C2-OH F）和具有不同链长的疏水性烷基（PAN _T-C2 F，PAN _T-C4 F，PAN _T-C6 F和PAN _T-C8 F的季铵化纤维）的结构和特征。吸附实验结果表明，PAN _T-C2-OH含有亲水性羟基的F在5分钟的吸附平衡内对磷酸盐的最佳吸附容量（24.44 mg g ^-1）。此外，PAN _T-C2-OH ˚F可以有效地去除废水中磷酸盐宽pH范围内（3-9），即使在氯的存在^-，CO ₃ ^2-，NO ₃ ^-等的吸附动力学和等温线拟秒动力学和Langmuir等温线模型可以更好地描述磷酸盐的PAN _T-C2-OH F，表明其为单层化学吸附过程。此外，PAN _T-C2-OH F具有至少10倍的优异可回收性，并且对磷酸盐（0.02 mg PL^-1）在实际废水中。简而言之，这项研究为PAN _T-C2-OH F作为一种新型的环境吸附剂提供了证据，该吸附剂具有高效，高选择性和可重复使用性，可以去除和回收磷酸盐。