ABSTRACT

The objectives of this work were to develop polyacrylonitrile nanofibres modified with the commercial Cyanex 272 extractor and apply them for the recovery of gallium present in aqueous solution. The nanofibres were produced using the centrifugation technique, employing Forcespinning® equipment. The average nanofibre diameter ranged from 530 to 840 nm. The highest adsorption of gallium was achieved at pH 2.5, with a pseudo-second order kinetic model and the Freundlich equilibrium isotherm model providing the best fits of the experimental data. The thermodynamic parameters showed that the adsorption was spontaneous, favourable, and endothermic. The maximum capacity of the PAN/Cyanex 272 nanofibres for the recovery of gallium was 38.93 mg g⁻¹. In successive reuse cycles, the nanofibres showed a small decrease of the adsorption capacity for the metal after the first cycle, while the efficiency remained constant in the subsequent cycles. The desorption efficiency remained constant throughout the cycles, with values in the range 80%–90%. The findings demonstrated that PAN/Cyanex 272 nanofibres have excellent potential for use as adsorbents, providing good capacity for the recovery of gallium and satisfactory stability during reuse in several cycles.

摘要

这项工作的目的是开发用商业 Cyanex 272 萃取器改性的聚丙烯腈纳米纤维，并将它们用于回收水溶液中存在的镓。纳米纤维是使用离心技术生产的，采用 Forcespinning® 设备。平均纳米纤维直径范围为 530 至 840 nm。镓的最高吸附在 pH 2.5 时实现，伪二级动力学模型和 Freundlich 平衡等温线模型提供了实验数据的最佳拟合。热力学参数表明吸附是自发的、有利的和吸热的。PAN/Cyanex 272 纳米纤维回收镓的最大容量为 38.93 mg g ^-1. 在连续的重复使用循环中，纳米纤维在第一次循环后对金属的吸附能力略有下降，而在随后的循环中效率保持不变。解吸效率在整个循环过程中保持不变，值在 80%–90% 范围内。研究结果表明，PAN/Cyanex 272 纳米纤维具有用作吸附剂的出色潜力，为镓的回收提供了良好的能力，并且在多次循环重复使用期间具有令人满意的稳定性。