In this study, a graphene oxide/polyvinylidene fluoride (GO/PVDF) tight hollow fiber membrane (HFM) with improved permeability was fabricated via one-step direct spinning process to fractionate the dyes and salts (NaCl and Na2SO4) in textile wastewater. Scanning electron microscopy (SEM) indicated that the GO/PVDF HFM possessed a smooth and tight outer selective layer and a relatively porous and loose inner surface. The optimized HFM not only possesses a small mean pore radius of 1.14 nm, but also has a high pure water flux of 24.8 L/m2·h·bar. The stronger negative charge (− 40 mV at pH = 7) was obtained by the GO/PVDF HFM. Due to the synergistic effects of size exclusion and charge repulsion, the resultant HFM exhibited excellent rejection for dyes (i.e., close to 100% for Congo red and Methyl blue, 98.9% for Eriochrome black T) and low salts rejection (i.e., 1% for NaCl, 11% for Na2SO4). Besides, with appropriate addition of hydrophilic GO to the doped solution, the resultant membrane exhibited good hydrophilicity, antifouling property and excellent stability. The newly developed tight HFM would be of great significance for effective fractionation and treatment of textile wastewater.

中文翻译：

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制备具有提高渗透性的紧密 GO/PVDF 中空纤维膜，以有效分离纺织废水中的染料和盐

在这项研究中，通过一步直接纺丝工艺制备了一种具有改进渗透性的氧化石墨烯/聚偏二氟乙烯 (GO/PVDF) 紧密中空纤维膜 (HFM)，以分离纺织废水中的染料和盐类（NaCl 和 Na2SO4）。扫描电子显微镜 (SEM) 表明 GO/PVDF HFM 具有光滑且紧密的外部选择性层和相对多孔且松散的内表面。优化后的HFM不仅具有1.14 nm的小平均孔径，而且具有24.8 L/m2·h·bar的高纯水通量。GO/PVDF HFM 获得了更强的负电荷（pH = 7 时为 - 40 mV）。由于尺寸排阻和电荷排斥的协同效应，所得的 HFM 对染料表现出优异的排斥性（即，对刚果红和甲基蓝的排斥率接近 100%，98。Eriochrome black T 为 9%）和低盐截留率（即 NaCl 为 1%，Na2SO4 为 11%）。此外，在掺杂溶液中适当添加亲水性GO，所得膜表现出良好的亲水性、防污性和优异的稳定性。新开发的紧密HFM对于纺织废水的有效分馏和处理具有重要意义。