微波辅助对生物溶液超滤过程的影响

EFFECT OF MICROWAVE ASSISTED TECHNOLOGY ON ULTRAFILTRATION PROCESS OF BIOLOGICAL SOLUTION

为验证微波场强化植物提取的"膜超滤"假说机理,以聚醚砜超滤膜为研究对象,以膜通量为考察指标,结合膜和黄芪饮片显微结构的扫描电镜(SEM)表征,讨论了微波辐射对黄芪水提液超滤过程的影响。结果表明,驱动压力相同,微波辅助超滤30 min时,膜通量下降到初始值的57.36%,且膜表面观察不到凝胶层;而常规超滤30 min,膜通量已下降到初始值的30.29%,且膜表面覆盖一层约20μm的凝胶层。说明微波辐射能够减弱浓差极化现象,促进膜超滤过程中的物质传递。

To verify the hypothesis of＂membrane ultrafiltration＂on the enhancement of microwave field during the extraction of functional component from plant porous materials,choosing polyethersulfone（PES） as the ultra-filtration membrane,this paper presents a series of experiments on ultrafiltration of Astragalus water extraction solution.Combining the characterization of the microstructure of membrane by Scanning Electron Microscope（SEM）,we compare the ultrafiltration property of PES membrane assisted by microwave radiation with that by conventional method. Results indicate that with same driven pressure,the membrane flux decreased to 57.36%of initial value at microwave irradiation 200 W for 30 min,and it was 30.29%without microwave irradiation. Simultaneously,on the surface of membrane by the conventional method,gel layer（with thickness of about 20μm） can be observed,but nothing on the surface of membrane by the microwave assisted method.We suggest that the microwave irradiation is benefit to decrease the phenomenon of concentration polarization,promoting the process of mass transfer in the ultrafiltration of solution.