The present study aims at investigating the effects of multiple fabrication and design parameters on the performance of nanofiltration (NF) membranes. By employing the Plackett-Burman design method, obtained results demonstrate that citric acid (0–1.5 wt.%), TiO₂ (0–1 wt.%), and solvent evaporation time (1–3 min) are the top dominant factors affecting the pure water flux (PWF) of NF membranes. Also, the effects of the dominant factors and their corresponding interactions are statistically assessed through RSM technique by employing a quadratic model. Based on the ANOVA results the proposed models for the PWF and CaSO₄ rejection responses are statistically significant. The calculated optimum values for citric acid, TiO₂, and solvent evaporation time are 0.87 wt.%, 0.98 wt.%, and 1.34 min respectively. It is shown that by increasing the concentration of TiO₂ both PWF and rejection of membrane enhanced from 108.8–131.5 (lit.m⁻².h^-1) and from 73.5–83 % respectively. Furthermore, an increment in citric acid concentration leads to the promotion of the surface hydrophilicity and salt rejection of membranes. From the morphological point of view, increasing the TiO₂ concentration leads to formation of membranes with more porous sublayers while longer solvent evaporation times results in the formation of membranes with smaller macrovoids.

本研究旨在调查多种制造和设计参数对纳滤（NF）膜性能的影响。通过采用Plackett-Burman设计方法，获得的结果表明，柠檬酸（0–1.5 wt。％），TiO ₂（0–1 wt。％）和溶剂蒸发时间（1-3 min）是最主要的因素。影响NF膜的纯净水通量（PWF）。此外，通过采用二次模型，通过RSM技术对统计学上主要因素的影响及其对应的相互作用进行了评估。基于方差分析结果，所提出的PWF和CaSO ₄排斥反应模型具有统计学意义。柠檬酸TiO _2的最佳计算值，和溶剂蒸发时间分别为0.87重量％，0.98重量％和1.34分钟。结果表明，通过增加TiO ₂的浓度，PWF和膜截留率分别从108.8–131.5（lit.m ^-2 .h ^-1）和73.5–83％增强。此外，柠檬酸浓度的增加导致膜表面亲水性的提高和膜的脱盐性。从形态学的观点来看，增加TiO ₂浓度导致形成具有更多多孔亚层的膜，而更长的溶剂蒸发时间导致形成具有较小大孔的膜。