正渗透过程参数对渗透性能的影响

Effect of Process Parameters on Osmosis Performance During Forward Osmosis

正渗透是新的非热能驱动膜过程。采用界面聚合的方法制备了中空纤维复合膜。以Na2SO4、MgSO4、NaCl和Mg-Cl2水溶液作为驱动液进行了正渗透实验。实验表明,正渗透通量随着驱动液浓度的增加而增加,其中Na2SO4、MgCl2水溶液的渗透通量大于MgSO4、NaCl水溶液的。驱动液中无机盐向原水中扩散的渗透速率随无机盐浓度的增加而增加,且MgCl2>NaCl>Na2SO4>MgSO4。原水流速对正渗透通量的影响极小,而驱动液流速对正渗透通量的影响较大。

Forward（direct） osmosis（FO） is a non-thermal membrane process.A polyamide composite hollow fiber membrane was prepared by the interfacial polymerization.The reverse osmosis properties of the composite membrane were studied.In the present study,four draw solutions（Na2SO4,MgSO4,NaCl and MgCl2） were employed by the FO process to extract water from feed water across the composite membrane.Water osmosis flux was increased with the concentration of draw solutions in forward osmosis mode.The osmosis flux of Na2SO4,MgCl2 solutions is far higher than that of MgSO4,NaCl solutions.Change of osmosis velocity of the inorganic salts was described as MgCl2NaClNa2SO4MgSO4,and the osmosis velocity increased with the increase of inorganic salt concentration.Effect of raw water flux rate was generally very small on permeated flux,but the permeated flux was then raised to higher with increaseing draw solution flux rate.