A hybrid flotation–microfiltration cell for effluent treatment Original Research Article

Air bubbling is one of the techniques used to limit membrane fouling. Under appropriate conditions, it could be used also as the transport means for flotation, which is another efficient separation method applied in water treatment. The present paper reviews briefly the integration of both processes in the same tank, taking advantage of dispersed-air flotation combined with microfiltration (MF) by submerged membranes. Process parameters investigated were the nature, size and concentration of solid particles (zeolite, hydrotalcite, zinc hydroxide and iron colloidal particles), the type and concentration of selected ions (Zn2+, P–PO43−), the effect of gas flow rate, as well as the frequency and length of backflushing, which reduces the fouling of membranes.