气升式纳滤装置是一种新型膜过滤装置,具有能耗低、过滤条件温和等优点,在生化产品的分离纯化中应用前景广泛.以杆菌肽水溶液为过滤体系,采用孔径为0.9 nm的TiO2陶瓷纳滤膜,系统考察了曝气量和跨膜压差对气升式纳滤装置过滤性能的影响.结果表明,曝气可有效提升通量和截留率:当跨膜压差为0.3 MPa时,曝气量由20 L·h-1增大到100 L·h-1,通量和截留率分别提升34.0％和14.5％,在曝气量100 L·h-1时两者达到最大,进一步增大曝气量,通量和截留率开始下降;当跨膜压差为0.1、0.3、0.5 MPa时,对应的最优曝气量分别为60、100、140 L·h-1.并通过模型计算,分析了不同操作条件下,气升式纳滤装置流体力学性质和能耗的变化情况.%Due to the advantages of low energy consumption and mild filtration condition, airlift nanofiltration equipment as a new type one has a potential wide application in purifying and separating bio-products. With bacitracin aqueous as the test media, the effects of aeration rate and transmembrane pressure drop on filtration performance of airlift nanofiltration equipment using TiO2 ceramic membrane with a pore size of 0.9 nm were investigated systematically. The results show that the aeration can efficiently improve the flux and trapped ratio. When transmembrane pressure drop is 0.3 MPa, both the steady flux and the steady rejection increase firstly with increasing aeration rate and reach the maximum when aeration rate is 100 L·h-1, then decrease with further increasing aeration rate. When aeration rate increase from 20 L·h-1 to 100 L·h-1, the steady flux and the steady rejection increase by 34.0% and 14.5%, respectively. On the other hand, the optimal aeration rate is 60 L·h-1, 100 L·h-1 and 140 L·h-1, respectively, when transmembrane pressure is 0.1 MPa, 0.3 MPa and 0.5 MPa Meanwhile, based on mathematical modeling, the hydrodynamic and the energy consumption of airlift nanofiltration equipment at different operating conditions were also discussed.
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