کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
628705 | 1455492 | 2006 | 11 صفحه PDF | دانلود رایگان |
The parameters of the model comprising the polarization layer and the Spiegler–Kedem–Katchalsky model ofmembrane transport were determined for a series of nanofiltration membranes. Membranes with different NaCl retentions were chosen. The experiments were performed at the same hydrodynamic conditions using 0.1 M NaClas feed. Different approaches to the calculation of parameters are presented, including the concentration dependence of Ps and σ. It was found that only Ps = f(cs) substantially improved the fitting of the model. A strong dependenceof the real retention coefficient, R, on the electrolyte permeability coefficient, Ps, was described by the empirical relation R=(1+q0Psqi)−1. No regular relationship between Robs and the reflection coefficient, σ, was found. For some membranes the inequality σ<1 was obtained. A strong relation between the thickness of polarization layer, lpol, and R was found, expressed by the power function lpol = d0Rdi (r2 = 0.986). Thus, in the modeling of membrane transport, one should include the polarization layer into the model instead of applying the ready correlations which do not take into account the membrane properties.
Journal: Desalination - Volume 198, Issues 1–3, 30 October 2006, Pages 335–345