Enhancing foam drainage using foam fractionation column with spiral internal for separation of sodium dodecyl sulfate.

A new type of foam fractionation column with spiral internal had been designed for enhancing the foam drainage and thus for the removal of minute hazardous materials. The column without spiral internal was served as the comparison column, and an anionic surfactant sodium dodecyl sulfate (SDS) was used as the foaming solution. Effects of liquid loading volume, initial SDS concentration and superficial gas velocity on enrichment ratio and recovery percentage of SDS were investigated. The experimental results showed that the spiral column successfully enhanced the enrichment ratio of SDS by reducing countercurrent resistance between the rising bubbles and the entrained liquid of reflux. Enrichment ratio of SDS obtained by using the spiral column was 15.7, which was 2.5 times of that obtained by using the comparison column under the suitable operating conditions of liquid loading volume 0.4 L, initial SDS concentration 0.2g/L and superficial gas velocity 1.7 mm/s.