Composite PVA/PVDF pervaporation membrane for concentrated brine desalination: Salt rejection, membrane fouling and defect control

作者：Li Lin; Hou Jingwei^*; Ye Yun; Mansouri Jaleh; Chen Vicki

来源：Desalination, 2017, 422: 49-58.

DOI：10.1016/j.desal.2017.08.011

• Pervaporation
• Dip coating
• Submerged
• Brine desalination
• Complete salt rejection
• Long-term stability

Pervaporation has been considered as a promising candidate for brine treatment. In this study, composite pervaporation membranes were prepared by a simple dip coating method with commercially available materials, polyvinyl alcohol (PVA) and PVDF supporting membranes. The membrane with a thin PVA layer (similar to 0.3 mu m) had a high flux of 16.38 L/m(2) h with Milli-Q water at an operating temperature of 80 degrees C. However, gradual diffusion of the salt ions was observed on the membrane during single brine treatment (100 g/L NaCl). In comparison, the membrane with a thicker coating layer (similar to 0.8 mu m) could maintain the permeate conductivity at 1-1.5 mu S/cm for over 300 h' operation, with only minor loss of flux. Furthermore, stable salt rejection was demonstrated with different feed solutions, e.g. concentrated NaCl brine, feed containing organic and/or inorganic foulant, and model inland desalination brine. The membrane can maintain its original performance after 300 days storage at room temperature, and it showed satisfactory fouling resistance and cleaning efficiency. Finally, this work also explored the controlling of coating layer defects by comparing different coating techniques, and the effect of supporting membranes was also studied.

• 出版日期2017-11-15
• 单位UNESCO