Hydrodynamic study and optimization strategy for the surfactant recovery from aqueous solutions

Foam fractionation for recovery of cetyl pyridinium chloride (CPC) from aqueous medium was studied. The effect of process parameters such as air flow rate, foam height, feed concentration, pH, and time was investigated to optimize the process. The maximum recovery of CPC obtained was 97.71% to 94.18% with an enrichment ratio of 3 and 1.21 for 8 CMC to 20 CMC. The average bubble size of the foam in the fractionation column was estimated by the photographic technique from which interfacial area was determined. Effect of surfactants on the theoretical liquid side mass transfer coefficient (k(L)) was also investigated which is based on the determination of the diffusivity coefficient of surfactant on the surface of the liquid and was found to be 7.52 x 10(-3) m/s whereas the experimental liquid side mass transfer coefficient was determined from the local volumetric mass transfer coefficient (k(L)a) and was found to be 7.01 x 10(-3) m/s for the feed concentration of 20 CMC. (C) 2010 Elsevier BM. All rights reserved.