(378y) In situ Microextraction/Stripping Using Supported Liquid Membrane (SLM): A Comprehensive Numerical Study

Recently, micro-SLM (supported liquid membrane) in-situ extraction/stripping has drawn vast research attention for its advantages of high mass/heat transfer rate, much less sample consumption and automatic operation potential applied in drug purification and environmental element analysis. For both design and optimization purpose, a deep understanding of mass transfer mechanisms in the micro-SLM process is of vital importance. However, the interplay of molecule diffusion, interfacial extraction/stripping equilibrium and microflow (convection) at the microscale results in complicated mass transfer mechanisms, which remain unclear so far. In the present study, we established a comprehensive 3D numerical simulation to investigate the hydrodynamics and mass transfer behaviors in a spiral micro-SLM device and reveal its mass transfer mechanisms. Five different mass transfer mechanisms were first determined and explained in detail. Three dimensionless numbers were defined to distinguish these mass transfer mechanisms and generate a mechanism zoning map. The proposed model and the zoning map are very useful to predict the mass transfer behaviors of the micro-SLM process in both lab and industry.