陶瓷超滤膜在右旋糖酐分离中的应用

Application of ceramic ultrafiltration membranes for dextran separation

本文采用自制的陶瓷超滤膜分离右旋糖酐,研究了操作参数如压力、温度、膜面流速和料液浓度等对陶瓷超滤膜分离右旋糖酐的影响,并对操作参数进行了优化.所用陶瓷超滤膜材料为氧化锆,切割分子量约为2 700,纯水渗透率约为375L/(m^2·h·MPa).研究表明,增大操作压力,膜通量以及右旋糖酐的截留率均有所增加.当操作压力增加至0.3 MPa时,右旋糖酐与果糖的分离因子最大,二者的分离效果最好.温度变化时,膜通量随温度的升高而升高,但右旋糖酐的截留率随温度的上升而下降.适当增大膜面流速有利于增大膜通量和右旋糖酐的截留率.此外,还考察了陶瓷超滤膜在右旋糖酐分离纯化过程中的稳定性.当料液浓度为60g/L时,陶瓷膜在连续12h的运行过程中,膜通量稳定在24L/(m^2·h)左右,分离因子稳定在11.5以上.陶瓷超滤膜在右旋糖酐分离方面展现了良好的应用前景.

ZrO2 ultrafiltration membrane （MWCO=2 700） was used to separate and purify the dextran solution.The influences of operating pressure,temperature,crossflow velocity and feed concentration on membrane flux and retention rate as well as the stability were investigated.It was demonstrated that the membrane flux and retention rate of dextran increased with transmembrane pressure.When the transmembrane pressure was 0.3 MPa,the separation factor of dextran and fructose reached the maximum.With the increase of temperature,the membrane flux increased but the retention rate of dextran fell down.With the increase of crossflow velocity,the membrane flux also increased.When crossflow velocity was 2.8 m/s,retention rates of dextran achieved up to 92％.When the feed concentration was 60 g/L,the separation performance of ceramic membrane was almost stable in a 12 h operating test.The flux and separation factor were stable at 24 L/（m2 h） and 11.5,respectively.The results indicated that the ZrO2 ultrafiltration membrane exhibited a good potential application in the separation and purification of dextran.