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纳米孔膜的过滤类似于反渗透和超滤,均属于压力驱动的膜过程,但其传质机理却有所不同。根据实验数据用作图的方法得出膜的真实截留率,进而求出膜面浓度。通过实验发现,细孔模型中对特征参数σ和ω的计算与实验值有一定的出入,主要是由于在细孔模型中只考虑了结构尺寸对截留率的影响,而在道南效应决定膜对盐的截留性能的情况下,截留性能主要依赖于离子和膜之间的静电相互作用,电荷因素不容忽略,因此细孔模型用于描述纳米孔膜的分离机理时,其准确性不高。
Nanofiltration membrane filtration is similar to reverse osmosis and ultrafiltration, are pressure-driven membrane process, but the mass transfer mechanism is different. According to the experimental data used as a graph to get the true rejection of the membrane, and then find the membrane surface concentration. The experimental results show that the calculation of the characteristic parameters σ and ω in the pore model has some discrepancies with the experimental values, mainly because only the influence of structure size on the rejection rate is considered in the pore model. However, In the case of salt rejection performance, the entrapment performance mainly depends on the electrostatic interaction between the ions and the membrane, and the charge factor can not be neglected. Therefore, the pore model is not accurate enough to describe the separation mechanism of the nanoporous membrane.