正渗透膜活性层朝向对正渗透过程的影响研究

Study on the Membrane Orientation in FO Process

为了研发和实用化PA正渗透系统,通过在线实时监测研究了一种新型聚酰胺(PA)正渗透膜的活性层在朝向料液(active layer-facing-feed solution,AL-FS)和汲取液(active layer-facing-draw solution,Al-DS)2种模式下的正渗透水通量、反向溶质通量、特性反向通量和脱盐率等4大因素及其变化规律。结果表明:在汲取液浓度较低时,2种模式下的水通量、反向溶质通量大致相当;在汲取液浓度较高时,AL-DS模式的水通量要高于AL-FS模式的水通量,同时,AL-DS模式的反向溶质通量大约是AL-FS模式的反向溶质通量的2倍;在AL-FS模式下的特性反向溶质通量略低于AL-DS模式下的特性反向溶质通量;AL-FS模式下的脱盐率略高于AL-DS模式下的脱盐率。

The variation of permeate flux,reverse solute flux,specific reverse solute flux and salt rejection of forward osmosis of a new developed polyamide(PA) FO membrane was studied via online real-time monitoring when the membrane orientation was AL-FS and AL-DS mode.It was found that the permeate flux and reverse solute flux of the PA membrane in the AL-DS mode and in the AL-FS mode were approximately equivalent when the draw solution concentration was low.The permeate flux of the PA FO membrane in the AL-DS mode was higher than that in the AL-FS mode and reverse solute flux in the AL-DS mode was almost twice as much than that in the AL-FS mode when the draw solution concentration was high.The specific reverse solute flux of PA membrane in the AL-FS mode was slightly lower than that in the AL-DS mode.The desalination ratio of PA membrane in the AL-FS mode was slightly higher than that in the AL-DS mode.