Department of Chemical Engineering, S.V. National Institute of Technology, Surat 395007, Gujarat, India.
J Hazard Mater. 2010 Aug 15;180(1-3):309-15. doi: 10.1016/j.jhazmat.2010.04.032. Epub 2010 Apr 24.
Removal of heavy metals from wastewater is of critical importance due to their high toxicity and tendency to accumulate in living organisms. In the present work, performance of a nanofiltration (NF) membrane has been studied to separate cadmium and nickel ions from multicomponent aqueous solutions at different operating conditions. It is observed that the separation of cadmium and nickel ions increases with increase in applied pressure and decreases with increase in feed concentration at a constant feed flow rate. The maximum observed solutes rejection of cadmium and nickel ions are 80.57% and 85.27% for CdCl(2)-NiCl(2)-water system and 97.26% and 98.90% for CdSO(4)-NiSO(4)-water system, respectively, for an initial feed concentration of 0.005 g/L. This difference in rejection is due to the charge density of the anions. It is also observed that the order of solute rejection sequence is inversely proportional to the diffusion coefficient. The NF membrane is characterized by an irreversible thermodynamics (IT) based Spiegler-Kedem model, coupled with film theory. Boundary-layer thickness and membrane transport parameters are estimated using Levenberg-Marquadt method. The estimated parameters are used to predict the membrane performance and found that the predicted values are in satisfactory agreement with the experimental results.
由于重金属毒性高且易于在生物体中积累，因此从废水中去除重金属至关重要。本工作研究了纳滤（NF）膜在不同操作条件下从多组分水溶液中分离镉和镍离子的性能。结果表明，在恒定进料流速下，随着操作压力的增加和进料浓度的增加，镉和镍离子的分离率增加。对于 CdCl2-NiCl2-水体系，最大观察到的镉和镍离子的溶质截留率分别为 80.57%和 85.27%，对于 CdSO4-NiSO4-水体系，最大观察到的镉和镍离子的溶质截留率分别为 97.26%和 98.90%，初始进料浓度为 0.005 g/L。这种截留率的差异是由于阴离子的电荷密度造成的。还观察到，溶质截留顺序与扩散系数成反比。NF 膜的特征在于基于不可逆热力学（IT）的 Spiegler-Kedem 模型，与膜理论相结合。使用 Levenberg-Marquadt 方法估算边界层厚度和膜传输参数。使用估算的参数来预测膜性能，发现预测值与实验结果吻合良好。
