Analysis of dissolved oxygen removal in hollow fibre membrane modules: effect of water vapour

A mathematical model with consideration of water vapour permeation has been developed to describe vacuum degassing in a hollow fibre membrane module. The dissolved oxygen (DO) removal in ultrapure water production has been considered in the study. The results indicate that the water vapour permeation enhances the mass transfer of DO across the membrane and thus, favors the DO removal. This beneficial effect of the water vapour permeation is more remarkable in the lumen-feed operation than that in the shell-feed operation. As the module length increases, the improvement on the DO removal due to the water vapour permeation is diminished. Using the vacuum degassing, length of the hollow fibre modules has to be restricted within 1.6 m in order to maintain the efficiency of DO removal. The experimental data for DO removal using a silicone rubber membrane module is in good agreement with the simulation results and strongly supports the analysis.