The application of the conventional flotation column to wastewater tre
atment has failed to realize its full potential, mainly because of ina
dequate mixing (or backmixing) and non-uniform dispersion of bubbles i
n the column. Thus, the challenge lies in the development of a mechani
cal design, which can provide proper hydrodynamic conditions that will
result in efficient separation, with high throughput. This paper desc
ribes a new column design, in which multiple draft tubes were used. Te
st results demonstrate that this new design is superior to that of the
conventional flotation column for wastewater treatment.