Gas-dispersive capability of a hollow-fiber membrane, manufactured specifically for the use in fine bubbles generation, is tested for attaining high gas-liquid mass transfer rate under low-gas-throughput, shallow-sparging (at depths < 0.7 m) conditions. The hollow fiber is wound In a plane spiral form, each of which can be piled in a cylindrical module. A bubble column is used in the presence as well as absence of a draft tube, which the module can fit to and serve. as part of. To enhance the effectiveness in the module’s generating fine bubbles, electrolytes are added to the liquid phase, water. Over a superficial gas velocity range of 0.1-2 mm/s, the hollow-fiber module (in comparison to conventional perforated-plate distributors) demonstrates, even with moderate gas-supply pressures (<0.3. MPa), as high as 3-fold and 20-fold increases in the volumetric mass transfer coefficient in the absence and presence of the electrolytes, respectively. The former has been attained with a negligible increase in the gas holdup; the latter has accompanied a large (similar to 20-fold) increase in the gas holdup. While in the latter case the bubbles are very finely dispersed, the draft-tube mode of operation secures still reasonable liquid circulation with nonclustering, spherical bubbles uniformly dispersed in each of the core and annular regions of the bubble column.