A hybrid MF process based on flotation

In the present work, a two-stage process was used for zinc ions removal from aqueous solutions. The first stage consists of the sorption of metal ions onto zeolite and the second one the separation of the metal-loaded sorbent in a hybrid cell. The later combines dispersed-air flotation and micro-filtration in one unit. The main parameters investigated were zeolite concentration, solution pH, collector type and concentration as well as the submerged membranes backflush. The higher the zeolite dose the higher the transmembrane pressure and the lower the permeability was observed. Backflush found to have a small effect on hybrid cell operation, under the studied conditions, while the collector type was a crucial parameter. Zinc ion removal was almost complete. A 90% zeolite recovery by flotation, which was the foreseen aim, reached successfully. (C) 2003 Elsevier B.V. All rights reserved.